# Fileset

[MS 20250724.pdf](https://mdr.nims.go.jp/filesets/5e5d65ac-413b-43b2-aa44-e1e512ca1c49/download)

## Creator

Yotaro Kasahara, [Takashi Takeda](https://orcid.org/0000-0002-5254-2819), [Shun Dekura](https://orcid.org/0000-0003-2498-6428), [Hayato Anetai](https://orcid.org/0000-0001-7469-8489), [Atsuro Takai](https://orcid.org/0000-0003-3457-3352), [Ichiro Hisaki](https://orcid.org/0000-0002-8170-5605), [Masayuki Takeuchi](https://orcid.org/0000-0002-0207-0665), [Tomoyuki Akutagawa](https://orcid.org/0000-0003-3040-1078)

## Rights

This document is the Accepted Manuscript version of a Published Work that appeared in final form in The Journal of Physical Chemistry B, copyright © 2025 American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see https://doi.org/10.1021/acs.jpcb.5c04027.[In Copyright](http://rightsstatements.org/vocab/InC/1.0/)

## Other metadata

[Ring-Size Effect on Molecular Assembly Structures and Optical Properties of <i>C</i><sub>3</sub>-Symmetrical Dehydrobenzoannulene Derivatives](https://mdr.nims.go.jp/datasets/8ef1b2b0-0a5b-4679-9671-33629254c04c)

## Fulltext

1  Ring-Size Effect on Molecular Assembly Structures and Optical Properties of C3-Symmetrical Dehydrobenzoannulene Derivatives  Yotaro Kasahara,a,b Takashi Takeda,a, b, c* Shun Dekura,a, b Hayato Anetai,d Atsuro Takai,d Ichiro Hisaki,e Masayuki Takeuchi,d, f and Tomoyuki Akutagawa a, b*  a Graduate School of Engineering, Tohoku University, Sendai 980-8579, Japan, b Institute of Multidisciplinary Research for Advanced Materials (IMRAM), Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577, Japan, c Faculty of Science, Shinshu University, 3-1-1 Asahi, Matsumoto 390-8621, Japan, and d Molecular Design and Function Group, National Institute for Material Science (NIMS), 1-2-1 Tsukuba, 305-0047, Japan, e Graduate School of Engineering Science, The University of Osaka, Toyonaka, Osaka 560-8531, Japan. f Research Center for Autonomous Systems Materialogy (ASMat), Institute of Integrated Research (IIR), Institute of Science Tokyo, 4259 Nagatsuta-cho, Midori-ku, Yokohama, 226-8501 Japan.   RECEIVED DATE (to be automatically inserted after your manuscript is accepted if required according to the journal that you are submitting your paper to) Institute of Multidisciplinary Research for Advanced Materials (IMRAM), Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577, Japan Phone:  +81-22-217-5653 Fax:   +81-22-217-5655 E-mail  takashi@shinshu-u.ac.jp and akutagawa@tohoku.ac.jp mailto:takashi@shinshu-u.ac.jpmailto:akutagawa@tohoku.ac.jp  2  Abstract: We reported that C8[12]DBA, a C3-symmetric hexadecahydrotribenzo[12]annulene ([12]DBA) with a pore surrounded by three −C≡C− bonds, forms a stable molecular glass during cooling from the liquid state when an octylbenzoate group was introduced at the molecular terminal. In this study, to understand the influence of the molecular structure of C3-symmetric DBA derivatives on molecular assembly structures and optical properties, we newly synthesized C8[18]DBA, which has a pore surrounded by more elongated −C≡C−C≡C− bonds. Furthermore, a comparison was made with an octylbenzoate-substituted triphenylene derivative (C8Trip) that has C3 symmetry and no pore at the molecular center. The strength of intermolecular interactions decreased in the order C8[18]DBA > C8Trip > C8[12]DBA. C8[18]DBA formed π-dimers and gave crystalline molecular assemblies, whereas in C8[12]DBA, the suppression of π-π interactions stabilized the glass state. C8[18]DBA did not exhibit dielectric anomalies, whereas C8Trip and C8[12]DBA showed dielectric relaxation associated with the thermal motion of the octyl ester chains. Furthermore, while C8[12]DBA exhibited similar fluorescence spectra in solution and solid states, both C8[18]DBA and C8Trip exhibited aggregation-induced quenching with a significant decrease in fluorescence intensity in the solid state.      3  1. Introduction Between single crystals and liquids, there exist mesophases such as liquid crystal phase1 and/or plastic crystals.2,3 These mesophases are in a thermally excited dynamic state where molecular rotation and diffusion are active. Recently, by precisely controlling the degrees of freedom of molecular rotation dynamics, it has become possible to show physical properties such as ferroelectricity, ion conductivity, and barocaloric effect.4–11 On the other hand, organic glasses without order in molecular center-of-mass position and molecular orientation suppress grain boundaries and crack formation in thin films, exhibiting high dielectric strength and excellent durability. As such, they are important materials for forming stable thin film structures in organic electronics.12–20 From a molecular design perspective, controlling intermolecular interactions and understanding glass formation are critical challenges. To date, molecular glasses based on designs incorporating molecular shape, structural flexibility, and intermolecular interactions have been reported, including starburst-type molecules developed by Shirota et al.,12,13 propellane skeletons, camphorsulfonamides, pillararene, and cholesteryl group-substituted carbazole derivatives.21–28 In molecules capable of forming both crystalline and glassy phases, chromic phenomena and polarization properties associated with changes in molecular arrangement have been observed, and the relationship between phase transition behavior and intermolecular interactions has been discussed.23,26–28 We have discovered that rod-shaped dumbbell molecules linked with camphorsulfonamide and adamantylamine undergo a transition from a liquid to a plastic crystal and then to an orientational glass.25 In such systems, the correlation between intermolecular interactions and dielectric relaxation, chromic behavior, and luminescence properties can be discussed at the molecular level. However, due to the non-equilibrium nature and structural disorder of molecular glasses, it is difficult to understand intermolecular interactions using methods such as X-ray crystallographic analysis. Symmetrical polyaromatic hydrocarbons (PAHs) such as porphyrin, pyrene, perylene, and pentacene tend to form crystalline molecular assemblies via π-stacking columns and multiple C–H•••π   4  interactions, and do not form a glass state.29,30 C3-symmetric hexadehydrotribenzo[12]annulene ([12]DBA), where three phenylene groups are bridged by ethynyl groups (−C≡C−), has a pore at the molecular center, resulting in limited intermolecular interaction, and thus is expected to exhibit intermolecular interactions different from those of symmetric PAHs.31,32 Additionally, [12]DBA exhibits distinctive physical properties in terms of optical characteristics, aromaticity, redox properties, and single-molecule conductivity, and is known to exhibit luminescence behavior with a large Stokes shift.33–40 The molecular assembly structures of [12]DBA derivatives change dramatically depending on the position and type of substituents. Unsubstituted [12]DBA forms a herringbone packing structure due to multiple C−H•••π interactions,41 whereas introducing substituents such as carboxyl groups at the 2, 6, 10-positions or 2, 3, 6, 7, 10, 11-positions, diverse crystalline structures with varying dimensionalities emerge, including one-dimensional (1D) columns,42–44 two-dimensional (2D) layers,43,45–47 three-dimensional (3D) tetrahedral structures,43 and isolated dimers.22,48 Additionally, the formation of 1D columnar liquid crystals49 and nanostructures38,39,50–52 has also been reported.  We reported molecular glass based on [12]DBA with bulky octylbenzoate groups at 2,3,6,7,10,11-position (C8[12]DBA in Scheme 1).22 [12]DBA derivatives with phenylcarboxyl and methylbenzoate groups form crystalline states made up of HOF and π-stacked dimer structures through hydrogen-bonding and π-stack interactions. These crystals cause a red-shift in the absorption spectrum because of strong π-π interactions. On the other hands, the intermolecular π-π interactions of C8[12]DBA were weakened due to steric hindrance of the phenylene units and thermal fluctuation of octyl-ester chains, inhibiting crystallization, and C8[12]DBA exhibited isolated-molecule-like luminescence behavior and dielectric relaxation phenomena caused by thermal fluctuations in the alkyl ester chains in the solid state. This result provides a new design strategy for π-molecular-based glass materials. However, many details regarding the intermolecular interactions contributing to the formation of the glass phase and their dynamics remain unclear.   5  In dehydrobenzoannulene (DBA) derivatives, the ring size can be controlled by designing the synthetic precursor.53,54 Iyoda, Diederich, Haley, Goodson, Komatsu, and others have shown the redox properties and optical properties of DBA derivatives with various ring sizes.33,37–39,53,55,56 Furthermore, Tahara, Tobe, De Feyter, and others have reported the formation of nanostructures on substrate surfaces and the intermolecular fastener effect of alkoxy-substituted DBA derivatives.50,57 Hisaki et al. have reported on the formation of HOF materials based on -expanded DBA derivatives and their gas adsorption behavior.45–47,58–60 By understanding the correlation between the ring size of DBA derivatives and their molecular assembly structures, the design strategy for molecular glasses of DBA derivatives can be clarified. In this study, we synthesized [18]DBA derivatives (C8[18]DBA in Scheme 1) formed by more elongated −C≡C−C≡C− bonds with larger central pore and the corresponding smaller triphenylene derivative without pore structure (C8Trip in Scheme 1), and compared their phase transition behavior, molecular assembly structures, dielectric, and optical properties with C8[12]DBA. Additionally, single-crystal X-ray structural analyses of the corresponding methylbenzoate derivatives (C1[12]DBA, C1[18]DBA, and C1Trip in Scheme 1) were performed to evaluate the molecular arrangement patterns in the -cores.   Scheme 1. Chemical structures of C8[n]DBA, C1[n]DBA (n = 12 or 18), C1Trip and C8Trip.    6  2. Experimental Section General. Solution phase 1H (400 MHz) and 13C (100 MHz) NMR spectra were recorded on a Bruker Avance III 400 or a JEOL JNM-ECZ400S NMR spectrometer. Chemical shifts () are expressed in ppm with reference to tetramethylsilane (1H 0.00 ppm) or residual nondeuterated solvent (CDCl3; 13C 77.0 ppm) as an internal standard. Mass spectra were recorded on a JMS-700 spectrometer at the NMR and MS Laboratory, Graduate School of Engineering, Tohoku University. Elemental analyses were performed on a Microcoder JM10 at the Elementary Analysis Laboratory, Institute of Multidisciplinary Research for Advanced Materials, Tohoku University. IR spectra were measured on a Thermo Scientific NICOLET 6700 FT-IR spectrometer. Thermogravimetric (TG) analysis was performed on a Rigaku Thermoplus EVO-2 at a scan rate of 10 K/min under a nitrogen atmosphere. Differential scanning calorimetry (DSC) analysis was conducted using a Mettler Toledo DSC-1 at a scan rate of 10 K/min. Microscopic observations were made using a Nikon ECLIPSE LV100ND, and stereomicroscopic and polarized light micrographs were taken using a Canon EOS kiss x5. The measurement sample was a powdered sample placed on a glass slide and sandwiched between cover glasses. Temperature control was performed by placing the sample on a temperature control stage (Limkam Scientific LTS-E350) to observe the sample and check its fluidity. Temperature-dependent powder X-ray diffraction (PXRD) patterns and were collected by using a Rigaku Ultima III diffractometer with Cu Ka radiation at  = 1.54187 Å. UV-vis absorption spectrum was measured on Perkin Elmer LAMBDA 750A Spectrometer. Fluorescent spectrum was measured on Shimadzu RF–6000. The fluorescence quantum yield in solution was determined using a SHIMADZU integrating sphere. For UV-vis spectra of solids, samples and KBr powder were mixed in an agate mortar, and pellets with a diameter of 13 mm were prepared by a pressure-molding machine and measured in the transmission configuration. Temperature-dependent dielectric constants of the compounds were measured using a four-probe AC impedance method at a frequency range of 1 kHz to 1 MHz (Hewlett-Packard, S4 HP4194A) with a liquid crystal cell in a Linkam LTS350 temperature-control system.   7  Powder of C8Trip and C8[18]DBA were fabricated on indium tin oxide (ITO) glass (SZ-A311P6N), which were sandwiched by a corresponding ITO glass to form a dielectric measurement cell with and electrode area of 0.16 cm2. The average electrode gap of C8Trip and C8[18]DBA was 115 µm and 30 µm, respectively.  Fluorescence Lifetime Measurements.  Fluorescence lifetimes were measured by a Horiba FluoroCube time-correlated single-photon-counting (TCSPC) system equipped with a TBX picosecond photon detection module (Figure S1). The samples were excited at 279 nm or 375 nm using pulse laser sources (Horiba PicoBrite series). Filters were used to minimize the scattered light at the excitation wavelength. The instrumental response (IRF) was recorded using a LUDOX HS-30 colloidal silica suspension in water (Aldrich). The simulation of decay profiles was performed by a nonlinear least-squares method. Preparation of C8Trip. Preparation of compound 1 was performed according to the procedure of previous report (Scheme S1).59 A solution of 1 (2.00 g, 2.18 mmol) in SOCl2 (80 mL) was refluxed for 15 h. The reaction mixture was evaporated to dryness under reduced pressure. The yellow residue was dissolved in dry dichloromethane (80 mL), and then, anhydrous triethylamine (2.34 μL, 16.9 mmol) and 1-octanol (2.34 mL, 14.8 mmol) was added. The resulting mixture was stirred at room temperature for 25 h, then quenched with water and extracted with dichloromethane. The combined organic layer was washed with water and brine and then dried over MgSO4. After evaporation of solvent under reduced pressure, the crude product was purified by silica gel column chromatography (CHCl3), affording C8Trip (1.72 g) as a white amorphous solid in 50% yield.  1H NMR (400 MHz, CDCl3): δ = 8.72 (s, 6 H), 7.98 (d, J = 8.3 Hz, 12 H), 7.39 (d, J = 8.3 Hz, 12 H), 4.32 (t, J = 6.7 Hz, 12 H), 1.77 (quint. J = 7.1 Hz, 12 H), 1.49 –1.20 (m, 60 H), 0.89 (t, J = 6.9 Hz, 18 H); 13C NMR (100 MHz, CDCl3): 166.4, 145.4, 139.4, 130.0, 129.5, 129.3, 129.2, 125.8, 65.3, 31.8, 29.2, 29.3, 28.7, 26.0, 22.6, 14.1; MS: calc. 1620.9719, found 1620.9718. E.A. Calc. for C108H132O12, C, 79.96 %; H, 8.20 %; N, 0.00 %; found C, 80.14 %; H, 8.50 %; N 0.15%.   8  Preparation of C8[18]DBA. C8[18]DBA was prepared by following Scheme S2. Preparation of compound 5 and 6 were performed according to the procedure of previous reports.60, 61  Preparation of 3. To a mixture of 4-boronobenzoic acid 2 (17.3 g, 104 mmol), K2CO3 (36.2 g, 262 mmol) in dry DMF was added 1-bromooctane (50 mL, 287 mmol). The mixture was stirred at 90 °C for 48 h. After cooling to room temperature, 3M H2SO4 aq. was added to the reaction mixture until the resulting bubble stopped. The mixture was extracted with ethyl acetate. The combined organic layer was washed with 2M LiCl aq., water and brine, then dried over MgSO4. After evaporation of the solvent under reduced pressure, the crude product was purified by silica gel column chromatography (hexane / ethyl acetate = 1/0→1/2) to give the mixture of 3 and unidentified impurity as a white solid (19.1 g). The following reaction was performed without further purification. 1H NMR (400 MHz, CDCl3): δ = 8.29 (d, J = 8.4 Hz, 2H), 8.16 (d, J = 8.3 Hz, 2H), 4.37 (t, J = 6.7 Hz, 2H), 1.81 (quint, J = 7.1 Hz, 2 H), 1.51-1.29 (m, 10 H), 0.90 (t, J = 7.2 Hz, 3H). Preparation of 7. Compound 3 (19.1 g, 68.7 mmol) and 6 (20.1 g, 33.7 mmol) were dissolved in mixed solvent of toluene (340 mL), water (170 mL) and 1,4-dioxane (170 mL). The solution was degassed with N2 bubbling. K2CO3 (7.14 g, 67.4 mmol), followed by Pd(dppf)Cl2 (2.42 g, 3.31 mmol) was added to the solution. The mixture was refluxed for 48 h. After cooling to room temperature, the resulting mixture was concentrated in vacuo and then extracted with ethyl acetate. The combined organic layer was washed with water and brine, then dried over MgSO4. After evaporation of the solvent under reduced pressure, the crude product was purified by twice silica gel column chromatography (eluent for first column chromatography: CH2Cl2, eluent for 2nd column chromatography: toluene / hexane = 1/1) to give the 7 as yellow oil (17.9 g, 69 %). 1H NMR (400 MHz, CDCl3): δ = 7.87 (d, 4H, J = 8.4 Hz), 7.56 (s, 2H), 7.15 (d, 4H, J = 8.8 Hz), 4.29 (t, J = 6.7 Hz, 4 H), 1.74 (quint. J = 7.0 Hz, 4H), 1.28-1.46 (m, 20H), 1.14 (s, 42H), 0.89 (t, J =6.8 Hz, 6H). Preparation of 8. To a solution of 7 (17.9 g, 19.8 mmol) in THF was added 1 M TBAF THF soln. (46.8 mL, 46.8 mmol). The reaction mixture was stirred for 1h at room temperature. The reaction was   9  quenched with water, then the resulting mixture was extracted with CHCl3. The combined organic layer was washed with water and brine, dried over MgSO4. After evaporation of the solvent under reduced pressure, the crude product was purified by silica gel column chromatography (toluene / CHCl3 = 1/0→0/1) to give the mixture of 8 as a dark purple oil (9.76 g, 83%). The following reaction was performed without further purification due to instability of the product. 1H NMR (400 MHz, CDCl3): δ = 7.89 (d, 4H, J = 8.8 Hz), 7.61 (s, 2H), 7.16 (d, 4H, J = 8.8 Hz), 4.29 (t, J = 6.7 Hz, 4 H), 3.41 (s, 2H), 1.74 (quint. J = 7.0 Hz, 4H), 1.28-1.46 (m, 20H), 1.14 (s, 42H), 0.89 (t, J =6.8 Hz, 6H).  Preparation of C8[18]DBA. Copper diacetate (II) (11.3 g, 62.3 mmol) was dissolved in MeOH (400 mL), pyridine (400 mL) and diethyl ether (80 mL). A solution of 8 (9.76 g, 16.5 mmol) in mixed solvent of pyridine (160 mL) and MeOH (160 mL) was added dropwise to the solution over a period of 2 h with a dropping funnel. The mixture was stirred for 0.5 h at 60 °C and the 22 h at room temperature under air. After the filtration of the reaction mixture, the black solution was concentrated in vacuo. The crude product was passed through the silica gel short path column (AcOEt), and then purified by silica gel column chromatography (toluene / CHCl3, 0% → 100% of CHCl3) and GPC (CHCl3) to give C8[18]DBA as a brown waxy solid (1.23 g, 13 %). The waxy solid was suspended in EtOH and the insoluble material was centrifuged and washed with EtOH to give brown solid of C8[18]DBA (1.19 g). 1H NMR (400 MHz, CDCl3): δ 7.93 (d, 12H, J = 8.0 Hz), 7.78 (s, 6H), 7.21 (d, 12H, J = 8.4 Hz), 4.29 (t, J = 6.7 Hz, 12 H), 1.74 (quint. J = 7.0 Hz, 12H), 1.28-1.46 (m, 60H), 0.89 (t, J =6.8 Hz, 18H); 13CNMR (100 MHz, CDCl3): 166.2, 143.7, 140.5, 134.7, 129.7, 129.6, 124.9, 80.7, 79.0, 65.3, 31.8, 29.2, 29.1, 28.7, 26.0, 22.6, 14.1; MS: calc. 1764.9719, found 1764.9718, E.A. Calc. for C120H132O12, C, 81.60 %; H, 7.53 %; N, 0.00 %. Found. C, 81.66 %; H, 7.53 %; N, 0.00 %. Single crystal structure X-ray structural analysis of C1Trip. Single crystals of C1Trip were obtained using a slow cooling method of the 1,4-dioxane. Crystallographic data were collected using a Rigaku RAPID-II diffractometer equipped with a rotating anode fitted with a multilayer confocal optics and using Cu Kα (λ = 1.54187 Å) radiation from a graphite monochromator (Table 1). Structural   10  refinements were performed using the full-matrix least squares method on F2. The initial structure was solved using SHELXT,62 and structural refinement was performed using OLEX2 software and SHELXL.63, 64 All the parameters, except for those of the hydrogen atoms, were refined using anisotropic temperature factors.   Table 1. Crystal data, data collection, and reduction parameters for C1[n]DBA and C1Trip.22, 60 Crystal C1[12]DBA22 C1[18]DBA60 C1Trip Chemical formula C72H48O12(C7H8) C78H48O12 2(C4H8O2) C66H48O12 5(C4H8O2) Formula weight 1197.23 1353.44 1473.56 T, K 100 153 120  Space group P21/n P21/c I2/a  a, Å 24.3648(9) 16.9723(2) 30.7338(8) b, Å 9.5585(4) 11.80850(10) 26.7298(7) c, Å 25.8540(10) 34.2230(5) 37.202(5) , deg 94.315(7) 93.9459(5) 101.889(8) V, Å3 6004.1(4) 1575.27(7) 29906(4) Z 4 4 16 Dcalc, g∙cm-3 1.324 1.314 1.309 , cm-1 7.19 − 7.75 Reflections measured 61595 40881 165054 Independent reflections 9541 14813 27278 Reflections used 9541 14813 27278 Rint 0.1237 0.056 0.0927 R1 a 0.0973 0.0771 0.0876 Rall 0.1689 − 0.1360   11  Rw(F2) a 0.2507 0.2381 0.2493 GOF 1.033 1.036 1.018 CCDC 2069905 1035274 2455080 a R1 = ||Fo| - |Fc|| /  |Fo| and Rw = ((|Fo| - |Fc|)2 / Fo2)1/2.  Theoretical calculation. DFT calculations were performed with the Gaussian 16 program package.65 The optimized molecular structures of C1Trip, C1[12]DBA, and C1[18]DBA were obtained by DFT calculations with the B3LYP/6-31G(d,p) basis set. The stationary point was assessed by a vibration frequency analysis. On the calculations to estimate the interaction energies between intra/inter dimer with counterpoise correction, we used the B3LYP functional and the 6-31G basis set. Van der Waals corrections are calculated based on DFT-D3 method with Becke–Jonson damping.66 The experimental crystal structure at 100 K was used as the dimer structure (Figures S2, 3). These structures were optimized with freezing all atoms except for hydrogen atoms. The intermolecular interaction energy in a dimer (Eintra), defined as the difference between the energy of dimer A-B and the sum of the energies of monomers A and B, was calculated using equation (1).  Eintra = E (dimer A-B) – [E(monomer A) + E(monomer B)]    (1)  Einter = E (tetramer, A-A~B-B) – [E(dimer, A-A) + E(dimer, B-B)]   (2)  Additionally, to estimate only the influence of the π-electron core, molecular interaction energies within dimers (Eπintra) and between dimers (Eπinter) were calculated using equations (1) and (2) with molecular structures excluding the methyl benzoate group (Figure S4).     12  3. Results and Discussion 3.1.  Preparation and electronic structures of C8[n]DBA and C8Trip. Preparation of C8[18]DBA and C8Trip were summarized in Schemes S1 and S2. C8Trip was synthesized by six-fold esterification of 1-octanol and the corresponding carboxylic acid with 50% yield (Scheme S1). C8[18]DBA was synthesized by cyclotrimerization of the corresponding diethynyl o-terphenyl with octylester groups (Scheme S2). The optimized molecular structure and electronic states of C1[n]DBA and C1Trip were calculated using DFT calculations with B3LYP/6-31G(d,p) basis set (Figures S5–7). The HOMO and LUMO of C1[12]DBA were −5.48 and −2.54 eV, respectively, and their orbital extended across the entire [12]DBA molecule with threefold symmetry (Figure S5). On the other hand, the HOMO and LUMO of C1[18]DBA exhibited pseudo-double degeneracy with energy levels of −5.70 and −2.48 eV, respectively. The frontier orbitals were localized at one vertex of the [18]DBA -core and its opposite edge, and the three-fold symmetry of the electronic structure was broken (Figure S6). This difference in the electronic structures between C1[12]DBA and C1[18]DBA is attributed to the difference in Hückel’s aromaticity.67 The HOMO and LUMO of C1Trip were observed at −5.98 and −1.95 eV, respectively, showing similar electronic states to C1[18]DBA (Figure S7), and π-orbitals were distributed also on the phenylene units. This difference in electronic structures is considered to influence intermolecular interactions. 3.2.  Thermal properties of C8[n]DBA and C8Trip. Thermogravimetry (TG) measurements of C8[18]DBA, C8[12]DBA, and C8Trip showed thermal decomposition accompanied by weight-loss at around 580, 540, and 600 K, respectively (Figure S8). Figure 1a shows the DSC curves for C8[18]DBA, C8[12DBA, and C8Trip. The as-grown brown powder sample of C8[18]DBA obtained by recrystallization turned black waxy solid at around 440 K, which is approximately 150 K lower than the thermal decomposition temperature observed in the TG chart (Figures 1b, c). Powder X-ray diffraction (PXRD) pattern of the black waxy solid showed a broadening of the diffraction pattern and sharp peak at 2 = 3.04 also changed to the broad peak (Figure S9), suggesting the formation of   13  amorphous solid after the thermal polymerization of C8[18]DBA. The differential scanning calorimetry (DSC) curve shows an irreversible phase transition at 350 K from the low-temperature phase (LTP) to high-temperature phase (HTP), and showed a small endothermic peak around 440 K, followed immediately by a large exothermic peak with H = −429 kJ mol−1 (Figure 1a). This H value is approximately three times that of the polymerization of a single −C≡C−C≡C− (−130 to −160 kJ mol−1),68 suggesting that the three −C≡C−C≡C− units within the molecule underwent quantitative thermal polymerization. On the other hand, no similar thermal polymerization reaction was observed in C8[12]DBA, which has a −C≡C− structure. The thermal stability of C8[n]DBA derivatives and C8Trip decreased in the order C8Trip > C8[12]DBA > C8[18]DBA. C8[18]DBA does not exhibit phase transitions below the thermal polymerization temperature, whereas C8[12]DBA showed a characteristic DSC baseline change at approximately 320 K during the cooling process from the liquid state, indicative of a glass (G) transition (Figure 1a, Figure S10, Table S1). This phase transition was a reversible phase transition without supercooling during the thermal cycle. On the other hand, C8Trip exhibited a reversible endothermic peak at 450 K (H = 20.2 kJ mol−1, S = 44.9 J K−1 mol−1; Figure 1a and Table S1), and polarized optical microscopy (POM) observations under cross-Nicole optical arrangement confirmed that this was a solid-liquid phase transition (Figure 1c). These results indicate that even when the structural units at the molecular ends are identical, differences in the molecular center unit can significantly alter phase transition behavior and intermolecular interactions. Notably, the glass transition temperature of C8[12]DBA (320 K) is more than 100 K lower than the melting point of C8Trip (450 K) and the polymerization point of C8[18]DBA (440 K), corresponding to weaker intermolecular interactions between C8[12]DBA molecules in the glass state.   14   Figure 1. Thermal behavior and phase transition of C8[n]DBA and C8Trip. (a) DSC curves of C8[18]DBA (red line with 1st and 2nd scans), C8Trip (blue line), and C8[12]DBA (black line). (b) Images of as-grown C8[18]DBA powder at 298 K (top) and 538 K (bottom). (c) POM images of the solid phase of C8Trip at 455 K (top) and the isotropic liquid phase at 483 K (bottom). The scale bar is 300 m.    -Stacking interaction of C1[n]DBA and C1Trip. The intermolecular interactions between the π-cores were evaluated based on single-crystal X-ray structural analyses of C1[n]DBA derivatives and C1Trip with methyl ester groups. The C1[12]DBA crystal contained one toluene as the crystallization   15  solvent. The annulenes at the molecular center maintained a -planar structure, and the terminal phenyl groups were tilted at a dihedral angle () of 45–74° relative to the -core (Figure 2a and Figure S11a), forming a conformation that reduced steric hindrance between adjacent phenylene units. C1[12]DBA formed -dimers rotated 180° relative to each other, which formed a 1D column by shifting the -plane along the b-axis (Figure 2a). The average distance between annulene -planes within the -dimer was 3.35 Å, shorter than the sum of van der Waals radii of carbon atoms (3.4 Å), indicating weak - interactions between acetylene units (Figures 2a, b). On the other hand, the average distance between annulene -dimers was 3.92 Å, which was 0.6 Å longer than that within dimers, indicating that intermolecular interactions between -dimers were negligible. The  = 36.5–57.4° in C1[18]DBA is smaller than that of C1[12]DBA (Figure 2b, Figure S11b). This is due to the reduction of intermolecular steric hindrance between phenylene units in the -dimer as the molecular size increases. C1[18]DBA forms a slip-stacked type -dimer with a large -plane shift, forming a 1D column along the b-axis while minimizing steric hindrance at the terminal phenylene groups (Figure 2b). The average distance between the annulene planes of intra -dimer and inter -dimers was 3.28 Å for both, indicating significant - interactions despite the significant slip of the -plane. The  = 46–54° in C1Trip was similar to those of C1[12]DBA (Figure S11c). C1Trip formed a slip-stacked -dimer with a significantly shifted - plane, forming a non-uniform 1D column along the b-axis (Figure 2c). However, the average interplanar distances between the triphenylene units for intradimer and interdimer were 4.53 and 4.72 Å, respectively, and no significant intermolecular - interactions were observed due to severe steric hindrance at the terminal phenylene units. It was clarified that even when the structure of the terminal phenylene units is the same, intermolecular interactions within the -dimer and between -dimers can vary significantly depending on the size of the molecular structure.    16   Figure 2. -stacking interactions between C1[n]DBAs and C1Trip. (a) C1[12]DBA, (b) C1[18]DBA, and (c) C1Trip forming π-dimers in a one-dimensional column (top) and the average interplanar distance between annulene units (bottom). Intradimer and interdimer distances are shown in blue and red, respectively.  3.4. Molecular assembly structures of C8[n]DBA and C1Trip. C8[n]DBAs and C8Trip could not be obtained as single crystals, so their molecular assembly structures are discussed based on PXRD patterns. The temperature-dependent PXRD patterns of C8[12]DBA show only weak, broad reflections in both the LTP and the HTP, which is characteristic of a glass state in which the periodicity of molecular position disappeared (Figure 3a). On the other hand, the PXRD pattern of C8[18]DBA at 373 K shows a diffraction peak corresponding to a hexagonal lattice with a = 28.3 Å, suggesting that the molecular -core is arranged in a hexagonal pattern within the ab plane (Figure 3a, red line, and Table S2). Concurrently, a broad reflection appears around 2~20°, suggesting a random state where the alkyl chains are disordered. The theoretical maximum molecular length for C8[18]DBA when the terminal alkyl chains adopt an all-trans conformation is 45 Å (Figure 3b), which is more than 16 Å longer than the observed length of the a-axis (28.3 Å). Therefore, the alkyl chains of C8[18]DBA are considered to be interdigitated in a random conformation. This molecular assembly structure is 3.35 Å3.92 Å(a)3.28 Å3.28 Å4.53 Å4.72 Å(b) (c)b b b  17  similar to the discotic hexagonal columnar (Colh) liquid crystal phase. However, C8[18]DBA does not exhibit a phase transition to the liquid crystal phase, where the thermal mobility of the molecular -cores required for liquid crystal formation is not realized. Furthermore, reflection peaks that cannot be attributed to the Colh liquid crystal phase were observed at 2 = 7.74 and 14.8° (Figure 3a, red line). The correlation lengths of these peaks were d = 11.4 and 5.99 Å, respectively, with a ratio of 1:2. The former peak at d = 11.4 Å is in good agreement with b = 11.80850(10) Å from the single-crystal X-ray structural analysis of C1[18]DBA (Figure 2a) and can be attributed to a peak reflecting the uniform dimerized π-stacking column. The PXRD pattern of C8Trip at 298 K shows a reflection peak corresponding to a periodic structure with d100 = 22.6 Å at 2 = 3.93°, and a peak corresponding to 200 reflections at 2 = 7.90° (Figure 3a, blue line, and Table S3), and a broad reflection peak appears around 2 ~ 20°. The maximum molecular length of C8Trip when the alkyl chains adopt an all-trans conformation is estimated to be 39 Å (Figure 3b), which is approximately 16 Å longer than the measured d100 = 22.6 Å. Therefore, it is considered that the alkyl chains adopt a random conformation in which they interdigitate with each other. Additionally, a peak corresponding to d = 14.0 Å was observed at 2 = 6.30° (Figure 3a, blue line), which is a half the value of b = 26.7298(7) Å from the single-crystal structure analysis of C1Trip (Figure 2c). Therefore, these peaks can be attributed to the periodicity of the non-uniform π-dimerized column along the b-axis. The molecular assembly structure of C8Trip is a 1D columnar structure composed of -dimers, similar to C8[18]DBA, its crystallinity was reduced compared to C8[18]DBA due to weaker intermolecular interactions (Figure 3c). Although three compounds of C8[12]DBA, C8[18]DBA, and C8Trip have similar terminal substituents, their crystallinities differed from one another.   18   Figure 3. Molecular assembly structure of C8[n]DBAs and C8Trip.  (a) Temperature-dependent PXRD patterns of C8[18]DBA (red line), C8Trip (blue line), and C8[12]DBA (black line). The open circles  in the figure indicate peaks attributable to the intermolecular spacing between the -cores, and the filled circles represent peaks attributable to the periodicity in the -dimerized column. (b) Model structures and maximum molecular lengths of C8[18]DBA, C8Trip, and C8[12]DBA, adopting the all-trans conformation of alkyl chains based on DFT calculation. (c) Schematic representations of the columnar structures of C8[18]DBA, C8Trip, and C8[12]DBA.  3.5. Intermolecular interaction energy. To quantitatively evaluate the intermolecular interactions between the -cores of C8[n]DBA and C8Trip, the stabilization energies of intradimer (Eintra) and interdimer (Einter) were calculated using the DFT-D method (B3LYP/6-31G and GD3BJ) based on the crystal structure of C1[n]DBA and C1Trip,  and the counterpoise correction was applied (Figure 4a, Table 2, and Figures S2, 3). Furthermore, the interaction energies of the -core structures of [12]DBA, 298 K373 K298 KC8[18]DBAC8[12]DBAC8Trip523 K373 K(a)C8[18]DBA45 ÅC8[12]DBA42 ÅC8Trip39 Å(b)~ 4.5 Å14.0 Å~ 3.3 Å11.6 Å(c) C8[18]DBAC8TripC8[12]DBA  19  [18]DBA, and Trip, which have had their terminal phenylene units removed, were also calculated using the same method as Eπintra and Eπinter (Figure 4b, Table 2, and Figure S4). The Eintra changes in the order of C1[12]DBA (−58.8 kcal mol−1) > C1[18]DBA (−42.8 kcal mol−1) > C1Trip (−35.7 kcal mol−1), with C1[12]DBA having the largest stabilization energy. On the other hand, the Eπintra for the -core alone was in the order of [12]DBA (−17.1 kcal mol−1) > [18]DBA (−15.8 kcal mol−1) >> Trip (−2.69 kcal mol−1), indicating that the intermolecular interaction for -dimer formation in Trip was significantly smaller. The Einter varied in the order C1[18]DBA (−51.5 kcal mol−1) > C1[12]DBA (−46.9 kcal mol−1) > C1Trip (−39.6 kcal mol−1), showing a different trend from the sequence of interactions within the -dimer. The Eπinter of the -core alone also showed a similar trend to Einter, with [18]DBA (−11.2 kcal mol−1) >> [12]DBA (−6.52 kcal mol−1) > Trip (−2.76 kcal mol−1). From a comparison of the absolute values of Einter and Eπinter, the contribution of intermolecular interactions originating from the annulene -core at the molecular center in C1[n]DBA was relatively small, and interactions between the phenylene units at the molecular ends contributed more to overall stabilization. Although the value of Eintra + Einter was the highest in C1[12]DBA, the crystallinity of C8[12]DBA was lower than that of C8[18]DBA or C8Trip. Therefore, it was found that the magnitude of intermolecular interaction energy is not necessarily related to crystallinity. In C1[18]DBA and C1Trip, there was no significant difference between the intermolecular interaction energy of Eintra and Einter, and the difference of these interactions was relatively small. On the other hand, C1[12]DBA forms strong -dimers, however, the intermolecular interactions are unbalanced, leading to random packing between -dimers and the formation of a molecular glass.     20  Table 2. Intermolecular interaction energies within dimers (Eintra) and between dimers (Einter) of C1[18]DBA, C1Trip, and C1[12]DBA, and the effect of π-electron cores (Eintra and Einter).a Compounds C1[18]DBA C1Trip C1[12]DBA Eintra / kcal mol−1 –42.8 –35.7 –58.8 Einter / kcal mol−1 –51.5 –39.6 –46.9 Compounds [18]DBA Trip [12]DBA Eπintra / kcal mol−1 −15.8 −2.69 −17.1 Eπinter / kcal mol−1 −11.2 −2.76 −6.52 a Calculated by B3LYP / 6–31G GD3BJ and counterpoise method.   Figure 4. Intermolecular interaction energies within and between -dimers in single crystals of C1[n]DBA. (a) Intradimer interactions (Eintra) and interdimer interactions (Einter) in C1[n]DBA and   21  C1Trip. (b) Intradimer interactions (Eπintra) and interdimer interactions (Eπinter) within π-dimers of [n]DBA, calculated excluding the phenylene moieties at the molecular ends.  3.6.  Dielectric properties and molecular dynamics. To evaluate the dynamics of C8[n]DBA and C8Trip, the variable frequency (f) and temperature (T) dependent dielectric constants were measured using the alternating current (AC) impedance method with an ITO sandwich electrode. Since C8Trip sublimates at temperatures above 400 K, it was evaluated under reduced pressure in the T-range of 173–400 K (Figure 5) and under N2 atmosphere in the T-range of 298–453 K (Figure S12). C8[18]DBA was evaluated in the T-range of 310–473 K under an N2 atmosphere (Figure S13). The real part dielectric constant (1) of C8[18]DBA was approximately 2.3 at 300 K, and a significant increase in 1 was observed around 430 K, where intermolecular polymerization reactions occur according to the TG chart. However, only a slight decrease of 1 was observed up to 420 K, and no f-dependence was observed. Therefore, C8[18]DBA does not exhibit molecular dynamics accompanied by changes in dipole moments in the crystalline phase (Figure S13). In C8Trip, a f-dependent 2 peak was observed in the T-range of 252−343 K, and at the same time, a dielectric anomaly appeared in 1 response (Figure 5). An increase in 1 associated with the transition to a liquid near the melting point was confirmed (Figure S12). This corresponds to the presence of dielectric relaxation caused by molecular motion accompanied by changes in dipole moments within the molecular assembly. Fitting of the Debye-type relaxation process using the peak value of 2 yielded an Arrhenius-type linear relationship, yielding an activation energy (Ea) of 61.2 kJ mol−1 and a prefactor of the relaxation time τ0 = 4.08×10−17 sec (Figure S14). The crystalline phase at T = 272 K exhibited a fast relaxation process with  = 1.59×10−4 sec, which is considered that motion attributable to -relaxation similar to that of alkyl side chain rotational fluctuations in polymer materials occur. A similar relaxation process has also been observed in C8[12]DBA with Ea = 52.3 kJ mol−1 and  = 5.84×10−16 sec (Figures S14, 15), indicating that both are governed by similar molecular motion.   22  C8[12]DBA shows a transition to a glassy state, whereas C8Trip forms a crystalline phase. The dielectric relaxation of both is thought to have common degrees of freedom due to flexible alkyl side chains. When these degrees of freedom are frozen, the weak intermolecular interactions of C8Trip form a crystalline phase, whereas C8[12]DBA forms a glassy state. C8[12]DBA can form effective π–π interactions between the [12]DBA cores. However, it is considered that structural relaxation without formation of π-dimers occurs upon freezing of the alkyl chain motion in the liquid state, leading to glass formation of C8[12]DBA. On the other hand, C8[18]DBA does not show clear dielectric relaxation, which is attributed to the hexagonal lattice of the π-stacking columns suppressing the molecular motion of the alkyl chains.   Figure 5. Temperature- and frequency-dependent (a) 1 and (b) 2 of C8Trip and DSC chart in the heating process under reduced pressure. Inset is schematic diagram of measurement sample cell.   3.7.  Optical properties. To discuss the relationship between molecular assembly structure and optical properties, the absorption-fluorescence spectra and absolute quantum yields of C8[18]DBA and C8Trip were compared with those of C8[12]DBA (Figure 6, Figure S16, and Table S4). The absorption spectrum of C8[12]DBA in CHCl3 showed a weak absorption at 370 nm and a strong GlassITO(a) (b)  23  absorption maximum at 332 nm with molar absorption coefficient  = 2.17×105 M−1 cm−1 (Figure S16). Additionally, the fluorescence spectrum in CHCl3 exhibited a fluorescence maximum at 511 nm, with shoulders at 470, 523, and 560 nm, and a quantum yield of 13%. Due to the D3h symmetric frontier orbitals of the [12]DBA -core, the S0→S1 transition is forbidden (Figure S5), and the observable transition band is the S0→S2 transition at 332 nm. The small absorption band at 370 nm corresponds to the S0→S1 transition, which is a forbidden transition. On the other hand, the fluorescence process is contributed to by non-radiative process and phosphorescence resulting from the relaxation process via the S1→S0 transition and the relaxation process via charge transfer from the 12-membered annulene ring to the benzene ring. The large Stokes shift of 10,500 cm−1 is a result of the previously mentioned optical process. C8[18]DBA in CHCl3 exhibited an absorption maximum at 356 nm with  = 1.02×105 M−1 cm−1 and had vibrational structures at 258, 286, 304, 333, 380, and 391 nm. The absorption maximum corresponds to the S0→S1 transition, which differs from the results for C8[12]DBA. This is because the threefold symmetry of the frontier orbitals is broken, allowing HOMO−LUMO transition (Figure S6). The fluorescence spectrum exhibited vibrational structures at 416 and 441 nm, with a fluorescence maximum observed at 452 nm, yielding a quantum yield of 29% and a Stokes shift of 5,970 cm−1. The observation of vibrational structures in the absorption-fluorescence spectra is consistent with the optical properties of the bare [18]DBA. On the other hand, the absorption spectrum of C8Trip in CHCl3 shows a strong absorption maximum at 310 nm with  = 1.47×105 M−1 cm−1, and the fluorescence spectrum shows a fluorescence maximum at 391 nm. The quantum yield and Stokes shift were 11% and 6,670 cm−1, respectively. Since the S0→S1 transition is an allowed in C8Trip, it exhibited absorption-fluorescence behavior similar to that of C8[18]DBA (Figure S7). The absorption-fluorescence spectra of solid-state C8[18]DBA and C8Trip were compared with those of glass-state C8[12]DBA. The glass state of C8[12]DBA exhibited an absorption maximum at 332 nm, and its spectral shape was consistent with that of the solution state (Figure 6a). The absence   24  of a significant red shift in the absorption maximum in the glass state indicates the absence of significant intermolecular interactions, corresponding to the D3h symmetry of frontier orbitals for the DBA -core. On the other hand, the optical properties of C8Trip and C8[18]DBA, which form crystalline phases, differed between the solution and solid phases. The fluorescence spectrum of C8[18]DBA in the solid state exhibited a fluorescence maximum at 471 nm, and the vibrational structure had disappeared, which was different from that in the solution state (Figure 6b). This is due to the presence of effective intermolecular interactions, similar to other [18]DBA derivatives. Additionally, the luminescence quantum yield of 2% of C8[18]DBA in the solid state was significantly reduced compared to the solution state, suggesting aggregation-induced quenching (ACQ) due to significant - interactions in the solid state. Similarly, the absorption maximum of C8Trip in the solid state (313 nm) exhibited only marginal red shift compared to the solution state (Figure 6c). The luminescence quantum yield of C8Trip in the solid state decreased from 11% in the solution state to 6%, exhibiting ACQ similar to that of C8[18]DBA. Since the frontier orbital coefficients of C8Trip extend to the phenylene units at the molecular ends, it is considered that red shift and ACQ of fluorescent spectrum in the solid state was exhibited due to intermolecular interactions between the phenylene units (Figure S7).   To gain insights into fluorescence quenching, we measured the fluorescence lifetime in CHCl3 and in the solid state at 298 K (Figures S17, 18, and Tables S5, 6). The fluorescence decay curve of C8[12]DBA in CHCl₃ solution at a wavelength of 513 nm was well fitted with three components of life time constants: 7.55 ns, 17.1 ns, and 1.43 ns. When compared to the fluorescence lifetime measurements of C1[12]DBA in DMF solution at wavelength of 520 nm reported by Douhal et al., the 1.43 ns and 7.75 ns life time constants can be attributed to emission from two charge-transfer states S1, while the 17.1 ns time constant can be attributed to emission from the T1 state. On the other hand, the fluorescence decay curve at wavelength of 523 nm in the glass state was reproduced with 6.36 and 27.7 ns, and the emission from the shortest-lived charge-transfer species S1 had disappeared. This   25  phenomenon was also observed in fluorescence lifetime measurements of C1[12]DBA in the crystalline state and is the main cause of the red shift in the fluorescence spectrum. The fluorescence decay curve of C8Trip in CHCl3 at a wavelength of 390 nm was well-fitted with a single component life  time constant of 11.5 ns. On the other hand, the fluorescence decay curve of C8Trip in the solid state at a wavelength of 410 nm was fitted with two components of life time of 5.70 and 15.7 ns, suggesting the presence of excimer emission due to intermolecular interactions between phenylene units at the molecular ends. Compared to the solution state, in the solid state of C8Trip, the intermolecular interactions between phenylene units with frontier orbitals caused a red shift in the fluorescence spectrum and a decrease in the emission quantum yield. For C8[18]DBA, the fluorescence decay curve at wavelength of 455 nm in CHCl3 was reproducible with life time constants of 1.03 and 2.18 ns. This decay process also yields similar results for the peaks observed at 410, 440, and 455 nm in the emission spectrum. On the other hand, the solid state C8[18]DBA exhibited a significant decrease in fluorescence lifetime, with the fluorescence decay curve at wavelength of 473 nm being reproducible with life time of 654 ps and 1.34 ns. This is a result of increased non-radiative decay process due to the formation of non-luminescent excimers, consistent with the significant decrease in fluorescence quantum yield observed in the solid state.  The ACQ and the crystallinity of the molecular aggregate structure of C8Trip and C8[18]DBA governed the optical properties.   26    Figure 6. Absorption-fluorescence spectra in CHCl3 and in the solid in KBr pellets. Blue and red spectra are absorption and fluorescence spectra, respectively. Solid and dash line spectra are solid and solution spectra, respectively. (a) C8[12]DBA for the excitation wavelengths for solution and solid are λex = 350 and 340 nm, respectively. (b) C8[18]DBA for the excitation wavelengths for solution and solid are λex = 395 and 395 nm, respectively. (c) C8Trip for the excitation wavelengths for solution (a)(b)(c)  27  and solid are λex = 310 and 310 nm, respectively. The vertical axis of the fluorescence spectra is normalized based on the quantum yield of C8[18]DBA in solution (29%).  4. Conclusion We compared the molecular assembly structures, dielectric properties, and optical properties of C8[18]DBA and C8Trip with those of C8[12]DBA, a molecular glass with same C3-symmetry, the same terminal substituents and different central ring size.C8[18]DBA and C8Trip formed crystalline solid phases with heterogeneous 1D columnar structures composed of -dimers. In particular, effective - interactions were observed in C8[18]DBA, forming a hexagonal lattice of 1D columns. Single-crystal X-ray structural analyses of methylbenzoate derivatives revealed that the - interactions and steric hindrance between terminal phenylene units varied depending on the ring size. Furthermore, dielectric constants showed that C8[12]DBA and C8Trip exhibited dielectric relaxation with similar activation energies derived from the thermal motion of alkyl ester chains, although glass and crystalline phases were due to differences in their freezing patterns upon cooling. On the other hand, C8[18]DBA exhibited no dielectric relaxation phenomenon due to the suppression of molecular motion by effective - interactions. The optical properties of each compound showed that C8[12]DBA exhibited similar spectra in both solution and solid states, while C8[18]DBA and C8Trip exhibited a significant decrease in luminescence intensity in the solid state, confirming ACQ. It was demonstrated that molecular assembly structures significantly influence optical properties, and successful guidelines for designing luminescent molecular glasses were established. In the future, by clarifying the correlation between the formation of molecular assembly structures and chemical structures using methods such as molecular dynamics simulations, it will be possible to design more sophisticated molecular glasses.  Acknowledgements   28  This work was supported by a Grant-in-Aid for Scientific Research on KAKENHI (Grant Numbers: JP20H05865, JP23K13715, JP24H01727, JP24K01452, JP24K01468, JP24K01475), ACT-X (Grant Numbers: JPMJAX23DF), JST SPRING (Grant Number: JPMJSP2114), the establishment of university fellowships towards the creation of science technology innovation (Grant Number: JPMJFS2102), Izumi Science and Technology Foundation, and the “Crossover Alliance to Create the Future with People, Intelligence and Material” project supported by the Ministry of Education, Culture, Sports, Science, and Technology.   ASSOCIATED CONTENT   Supporting Information Available. Experimental section, electronic structures, TG curves, PXRD patterns of C8[18]DBA after polymerization, POM images of C8[12]DBA, molecular assembly structures of C8[n]DBAs and C8Trip, single crystal structures of C1[n]DBAs and C1Trip, PXRD patterns of C8[n]DBAs and C8Trip, dielectric constants of C8[n]DBAs and C8Trip, optical properties of C8[n]DBAs and C8Trip, fluorescence lifetime of C8[n]DBAs and C8Trip, NMR spectra, HRMS spectrum, and cartesian coordinates. This material is available free of charge at http://pubs.acs.org.  References (1) Andrienko, D. Introduction to Liquid Crystals. J. Mol. Liq. 2018, 267, 520–541. (2) Timmermans, J. Plastic Crystals: A Historical Review. J. Phys. Chem. Solids 1961, 18, 1–8. (3) Staveley, L. A. K. Plastic Crystals. Nature 1979, 281, 411–411. (4) Akutagawa, T. Dynamic Molecular Assemblies toward a New Frontier in Materials Chemistry. Mater. Chem. Front. 2018, 2, 1064–1073. http://pubs.acs.org/  29  (5) Akutagawa, T. Chemical Design and Physical Properties of Dynamic Molecular Assemblies. Bull. Chem. Soc. Jpn. 2021, 94, 1400–1420. (6) Akutagawa, T.; Takeda, T.; Hoshino, N. Dynamics of Proton, Ion, Molecule, and Crystal Lattice in Functional Molecular Assemblies. Chem. Commun. 2021, 57, 8378–8401. (7) Sambe, K.; Takeda, T.; Hoshino, N.; Matsuda, W.; Shimada, K.; Tsujita, K.; Maruyama, S.; Yamamoto, S.; Seki, S.; Matsumoto, et al., Carrier Transport Switching of Ferroelectric BTBT Derivative. J. Am. Chem. Soc. 2024, 146, 8557–8566. (8) Sato, C.; Dekura, S.; Sato, H.; Sambe, K.; Takeda, T.; Kurihara, T.; Mizuno, M.; Taniguchi, T.; Wu, J.; Nakamura, et al., Proton Conduction in Chiral Molecular Assemblies of Azolium-Camphorsulfonate Salts. J. Am. Chem. Soc. 2024, 146, 22699–22710. (9) Harada, J. Plastic/Ferroelectric Molecular Crystals: Ferroelectric Performance in Bulk Polycrystalline Forms. APL Mater. 2021, 9, 020901. (10) Onodera, N.; Dekura, S.; Sato, T.; Mashiko, M.; Kurihara, T.; Mizuno, M.; Akutagawa, T. Ferroelectric-like Polarization Switching in Plastic Crystalline Succinonitrile. J. Am. Chem. Soc. 2025, 147, 19200–19209. (11) Li, B.; Kawakita, Y.; Ohira-Kawamura, S.; Sugahara, T.; Wang, H.; Wang, J.; Chen, Y.; Kawaguchi, S. I.; Kawaguchi, S.; Ohara, et al., Colossal Barocaloric Effects in Plastic Crystals. Nature 2019, 567, 506–510. (12) Shirota, Y. Organic Materials for Electronic and Optoelectronic Devices. J. Mater. Chem. 2000, 10, 1–25. (13) Shirota, Y. Photo- and Electroactive Amorphous Molecular Materials—Molecular Design, Syntheses, Reactions, Properties, and Applications. J. Mater. Chem. 2005, 15, 75–93. (14) Gao, J.; Zhang, S.; Cui, X.; Cong, X.; Guo, X.; Hu, R.; Wang, S.; Chen, J.; Li, Y.; Yang, G. Effective Optimization Strategy for Electron Beam Lithography of Molecular Glass Negative Photoresist. Adv. Mater. Interfaces 2023, 10, 2300194.   30  (15) Xu, H.; Kosma, V.; Giannelis, E. P.; Ober, C. K. In Pursuit of Moore’s Law: Polymer Chemistry in Action. Polym. J. 2018, 50, 45–55. (16) Felix, N. M.; Tsuchiya, K.; Ober, C. K. High‐resolution Patterning of Molecular Glasses Using Supercritical Carbon Dioxide. Adv. Mater. 2006, 18, 442–446. (17) Yang, D.; Chang, S. W.; Ober, C. K. Molecular Glass Photoresists for Advanced Lithography. J. Mater. Chem. 2006, 16, 1693–1696. (18) Dai, J.; Chang, S. W.; Hamad, A.; Yang, D.; Felix, N.; Ober, C. K. Molecular Glass Resists for High-Resolution Patterning. Chem. Mater. 2006, 18, 3404–3411. (19) De Silva, A.; Felix, N. M.; Ober, C. K. Molecular Glass Resists as High‐resolution Patterning Materials. Adv. Mater. 2008, 20, 3355–3361. (20) Sha, J.; Lee, J.-K.; Kang, S.; Prabhu, V. M.; Soles, C. L.; Bonnesen, P. V.; Ober, C. K. Architectural Effects on Acid Reaction-Diffusion Kinetics in Molecular Glass Photoresists. Chem. Mater. 2010, 22, 3093–3098. (21) Akahane, S.; Takeda, T.; Hoshino, N.; Akutagawa, T. Molecular Assemblies of Tetrahedral Triphenylmethanol and Triphenylamine Derivatives Bearing −NHCOCnH2n+1 Chains. Cryst. Growth Des. 2018, 18, 6284–6292. (22) Kasahara, Y.; Hisaki, I.; Akutagawa, T.; Takeda, T. Fluorescent Molecular Glass Based on Hexadehydrotribenzo[12]Annulene. Chem. Commun. 2021, 57, 5374–5377. (23) Miura, Y.; Murai, K.; Yamada, K.; Yoshioka, N. 4-Arylethynyl-5-Fluorobenzoyl-1-Methylimidazole Exhibiting Self-Recovering Mechanofluorochromism and Forming Fluorescence Molecular Glass. Bull. Chem. Soc. Jpn. 2021, 94, 2444–2450. (24) Onishi, K.; Ohtani, S.; Kato, K.; Fa, S.; Sakata, Y.; Akine, S.; Ogasawara, M.; Asakawa, H.; Nagano, S.; Takashima, Y. et al., State- and Water Repellency-Controllable Molecular Glass of Pillar[5]Arenes with Fluoroalkyl Groups by Guest Vapors. Chem. Sci. 2022, 13, 4082–4087.   31  (25) Sato, C.; Takeda, T.; Dekura, S.; Suzuki, Y.; Kawamata, J.; Akutagawa, T. Chiral Plastic Crystal of Solid-State Dual Rotators. Cryst. Growth Des. 2023, 23, 5889–5898. (26) Mizoue, R.; Kawana, M.; Takeda, T.; Hoshino, N.; Akutagawa, T. Ferroelectricity and Phase Change Memory of Bis(Tetradecylamide)-Substituted Benzene Derivatives. J. Phys. Chem. C 2023, 127, 1981–1991. (27) Kato, K.; Uchida, Y.; Kaneda, T.; Tachibana, T.; Ohtani, S.; Ogoshi, T. Alkoxylated Fluoranthene-Fused [3.3.3]Propellanes: Facile Film Formation against High π-Core Content. Chem. Asian J. 2024, 19, e202400080. (28) Zhang, M.; Lan, X.; Ding, M.; Han, C.; Liu, X. W.; Meng, Z.; Yu, Z.-Q.; An, Z. Dynamic Organic Phosphorescence Glass by Rigid-Soft Coupling. Angew. Chem. Int. Ed 2024, 64, e202415250. (29) Laschat, S.; Baro, A.; Steinke, N.; Giesselmann, F.; Hägele, C.; Scalia, G.; Judele, R.; Kapatsina, E.; Sauer, S.; Schreivogel, A.; Tosoni, M. Discotic Liquid Crystals: From Tailor-Made Synthesis to Plastic Electronics. Angew. Chem. Int. Ed. 2007, 46, 4832–4887. (30) Sergeyev, S.; Pisula, W.; Geerts, Y. H. Discotic Liquid Crystals: A New Generation of Organic Semiconductors. Chem. Soc. Rev. 2007, 36, 1902–1929. (31) Staab, H. A.; Graf, F. Zur konjugation in makrocyclischen bindungssystemen IV: synthese und eigenschaften von 1:2, 5:6, 9:10-tribenzo-cyclododeka-1. 5. 9-trien-3. 7. 11-triin. Tetrahedron Lett. 1966, 7, 751–757. (32) Campbell, I. D.; Eglinton, G.; Henderson, W.; Raphael, R. A. 1,2;5,6;9,10-Tribenzocyclododeca-1,5,9-Triene-3,7,11-Triyne and 1,2;5,6;9,10;13,14-Tetrabenzocyclohexadeca-1,5,9,13-Tetraene-3,7,11,15-Tetrayne. Chem. Commun. 1966, 87–89. (33) Gomez, E.; Gutiérrez, M.; Moreno, M.; Hisaki, I.; Nakagawa, S.; Douhal, A. Spectroscopy and Dynamics of Dehydrobenzo[12]Annulene Derivatives Possessing Peripheral Carboxyphenyl Groups: Theory and Experiment. Phys. Chem. Chem. Phys. 2018, 20, 7415–7427.   32  (34) Tahara, K.; Yoshimura, T.; Sonoda, M.; Tobe, Y.; Williams, R. V. Theoretical Studies on Graphyne Substructures: Geometry, Aromaticity, and Electronic Properties of the Multiply Fused Dehydrobenzo[12]Annulenes. J. Org. Chem. 2007, 72, 1437–1442. (35) Tahara, K.; Kozuma, H.; Venkatesh, V.; Ryomura, E.; Miyoshi, H.; Nakamachi, K.; Kishi, R.; Takahashi, H.; Nakano, M.; Tobe, Y. Generation of Aromatic (Dehydro)Benzoannulene Dications Stabilized by Platinum Catecholate Complexes. ChemPlusChem 2017, 82, 1052–1056. (36) Ohtomo, Y.; Ishiwata, K.; Hashimoto, S.; Kuroiwa, T.; Tahara, K. Revisiting Dehydrothiopheno[12]Annulenes: Synthesis, Electronic Properties, and Aromaticity. J. Org. Chem. 2021, 86, 13198–13211. (37) Tahara, K.; Fujita, T.; Sonoda, M.; Shiro, M.; Tobe, Y. Donors and Acceptors Based on Triangular Dehydrobenzo[12]Annulenes: Formation of a Triple-Layered Rosette Structure by a Charge-Transfer Complex. J. Am. Chem. Soc. 2008, 130, 14339–14345. (38) Enozawa, H.; Hasegawa, M.; Takamatsu, D.; Fukui, K.-I.; Iyoda, M. Synthesis of Tris(Tetrathiafulvaleno)Dodecadehydro- [18]Annulenes and Their Self-Assembly. Org. Lett. 2006, 8, 1917–1920. (39) Andersson, A. S.; Kilså, K.; Hassenkam, T.; Gisselbrecht, J.-P.; Boudon, C.; Gross, M.; Brøndsted Nielsen, M.; Diederich, F. Synthesis and Characteristics of a Nonaggregating Tris(Tetrathiafulvaleno)Dodecadehydro[18]Annulene. Chem. Eur. J. 2006, 12, 8451–8459. (40) Kiguchi, M.; Tahara, K.; Takahashi, Y.; Hasui, K.; Tobe, Y. Conductance of Single Triangular Dehydrobenzo[12]Annulene Derivative Bridged between Au Electrodes. Chem. Lett. 2010, 39, 788–789. (41) Irngartinger, H.; Leiserowitz, L.; Schmidt, G. M. J. Zur Konjugation in Makrocyclischen Bindungssystemen, XVI. Kristall‐ Und Molekularstruktur von 5.6.11.12.17.18‐Hexadehydro‐tribenzo[ a.e.i ]Cyclododecen. Chem. Ber. 1970, 103, 1119–1131.   33  (42) Hisaki, I.; Sakamoto, Y.; Shigemitsu, H.; Tohnai, N.; Miyata, M.; Seki, S.; Saeki, A.; Tagawa, S. Superstructure-Dependent Optical and Electrical Properties of an Unusual Face-to-Face, π-Stacked, One-Dimensional Assembly of Dehydrobenzo[12]Annulene in the Crystalline State. Chem. Eur. J. 2008, 14, 4178–4187. (43) Li, B.; Qiu, W.; Yap, G. P. A.; Dory, Y. L.; Claverie, J. P. Hydrogen-Bonded Organic Frameworks Based on Endless-Stacked Amides for Iodine Capture and Detection. Adv. Funct. Mater. 2024, 34, 2311964. (44) Li, B.; Yap, G. P. A.; St-Onge, V.; Mavragani, N.; Dao, T. T. H.; Baillargeon, P.; Fournier, P.; Dory, Y. L.; Claverie, J. P. Monoatomic Nickel Wires via Columnar Self-Assembly of Tribenzocyclyne Nickel Complexes. ACS Materials Lett. 2024, 6, 1288–1296. (45) Hisaki, I.; Nakagawa, S.; Ikenaka, N.; Imamura, Y.; Katouda, M.; Tashiro, M.; Tsuchida, H.; Ogoshi, T.; Sato, H.; Tohnai, N.; et al., A Series of Layered Assemblies of Hydrogen-Bonded, Hexagonal Networks of C3-Symmetric π-Conjugated Molecules: A Potential Motif of Porous Organic Materials. J. Am. Chem. Soc. 2016, 138, 6617–6628. (46) Pham, H. T. B.; Choi, J. Y.; Huang, S.; Wang, X.; Claman, A.; Stodolka, M.; Yazdi, S.; Sharma, S.; Zhang, W.; Park, J. Imparting Functionality and Enhanced Surface Area to a 2D Electrically Conductive MOF via Macrocyclic Linker. J. Am. Chem. Soc. 2022, 144, 10615–10621. (47) Pham, H. T. B.; Fang, X.; Choi, J. Y.; Huang, S.; Park, J. Nanoporous Synthetic Metal: A Nickel MOF with an Amino-Functionalized Macrocyclic Ligand. Chem 2025, 11, 102487. (48) Hisaki, I.; Osaka, K.; Shigemitsu, H.; Tohnai, N.; Miyata, M. Crystal Structure of a Hydrogen-Bond-Assisted Coaxially π-Stacked Dimer of a Hexadehydrotribenzo[12]Annulene ([12]DBA) Derivative. Chem. Lett. 2014, 43, 1104–1106. (49) Seo, S. H.; Jones, T. V.; Seyler, H.; Peters, J. O.; Kim, T. H.; Chang, J. Y.; Tew, G. N. Liquid Crystalline Order from Ortho -Phenylene Ethynylene Macrocycles. J. Am. Chem. Soc. 2006, 128, 9264–9265.   34  (50) Tahara, K.; Furukawa, S.; Uji-i, H.; Uchino, T.; Ichikawa, T.; Zhang, J.; Mamdouh, W.; Sonoda, M.; De Schryver, F. C.; De Feyter, S. et al., Two-Dimensional Porous Molecular Networks of Dehydrobenzo[12]Annulene Derivatives via Alkyl Chain Interdigitation. J. Am. Chem. Soc. 2006, 128, 16613–16625. (51) Tahara, K.; Lei, S.; Adisoejoso, J.; De Feyter, S.; Tobe, Y. Supramolecular Surface-Confined Architectures Created by Self-Assembly of Triangular Phenylene–Ethynylene Macrocycles via van Der Waals Interaction. Chem. Commun. 2010, 46, 8507. (52) Lei, S.; Tahara, K.; Müllen, K.; Szabelski, P.; Tobe, Y.; De Feyter, S. Mixing Behavior of Alkoxylated Dehydrobenzo[12]Annulenes at the Solid–Liquid Interface: Scanning Tunneling Microscopy and Monte Carlo Simulations. ACS Nano 2011, 5, 4145–4157. (53) Haley, M. M.; Brand, S. C.; Pak, J. J. Carbon Networks Based on Dehydrobenzoannulenes: Synthesis of Graphdiyne Substructures. Angew. Chem. Int. Ed. 1997, 36, 836–838. (54) Spitler, E. L.; Johnson, C. A.; Haley, M. M. Renaissance of Annulene Chemistry. Chem. Rev. 2006, 106, 5344–5386. (55) Anand, S.; Varnavski, O.; Marsden, J. A.; Haley, M. M.; Schlegel, H. B.; Goodson, T., 3rd. Optical Excitations in Carbon Architectures Based on Dodecadehydrotribenzo[18]Annulene. J. Phys. Chem. A 2006, 110, 1305–1318. (56) Nishinaga, T.; Nodera, N.; Miyata, Y.; Komatsu, K. Dehydro[12]- and -[18]Annulenes Fused with Tetrafluorobenzene: Synthesis, Electronic Properties, Packing Structures, and Reactivity in the Solid State. J. Org. Chem. 2002, 67, 6091–6096. (57) Tahara, K.; Johnson, C. A.; Fujita, T.; Sonoda, M.; De Schryver, F. D.; De Feyter, S.; Haley, M.; Tobe, Y. Synthesis of Dehydrobenzo[18]Annulene Derivatives and Formation of Self-Assembled Monolayers: Implications of Core Size on Alkyl Chain Interdigitation. Langmuir 2007, 23, 10190–10197.   35  (58) Hisaki, I.; Xin, C.; Takahashi, K.; Nakamura, T. Designing Hydrogen-Bonded Organic Frameworks (HOFs) with Permanent Porosity. Angew. Chem. Int. Ed. 2019, 58, 11160–11170. (59) Hisaki, I.; Ikenaka, N.; Tohnai, N.; Miyata, M. Polymorphs of Layered Assemblies of Hydrogen-Bonded Hexagonal Networks Caused by Conformational Frustration. Chem. Commun. 2016, 52, 300–303. (60) Hisaki, I.; Nakagawa, S.; Tohnai, N.; Miyata, M. A C3-Symmetric Macrocycle-Based, Hydrogen-Bonded, Multiporous Hexagonal Network as a Motif of Porous Molecular Crystals. Angew. Chem. Int. Ed. 2015, 54, 3008–3012. (61) Tahara, K.; Yamamoto, Y.; Gross, D. E.; Kozuma, H.; Arikuma, Y.; Ohta, K.; Koizumi, Y.; Gao, Y.; Shimizu, Y.; Seki, S.; Kamada, K.; Moore, J. S.; Tobe, Y. Syntheses and Properties of Graphyne Fragments: Trigonally Expanded Dehydrobenzo[12]Annulenes. Chem. Eur. J. 2013, 19, 11251–11260. (62) Sheldrick, G. M. SHELXT—Integrated Space-Group and Crystal-Structure Determination. Acta Crystallogr., 2015, 71, 3–8. (63) Dolomanov, O. V.; Bourhis, L. J.; Gildea, R. J.; Howard, J. A. K.; Puschmann, H. OLEX2: A Complete Structure Solution, Refinement and Analysis Program. J. Appl. Crystallogr. 2009, 42, 339–341. (64) Sheldrick, G. M. Crystal Structure Refinement with SHELXL. Acta Crystallogr. C 2015, 71, 3–8.  (65) Frisch, M. J.; Trucks, G. W.; Schlegel, H. B.; Scuseria, G. E.; Robb, M. A.; Cheeseman, J. R.; Scalmani, G.; Barone, V.; Petersson, G. A.; et al. Gaussian 16, Revision B.01; Gaussian, Inc.: Wallingford, CT, 2016. (66) Grimme, S.; Ehrlich, S.; Goerigk, L. Effect of the Damping Function in Dispersion Corrected Density Functional Theory. J. Comput. Chem. 2011, 32, 1456–1465.   36  (67) Frost, A. A.; Musulin, B. A Mnemonic Device for Molecular Orbital Energies. J. Chem. Phys. 1953, 21, 572–573. (68) Eckhardt, H.; Prusik, T.; Chance, R. R. Energetics of Diacetylene Photopolymerization: A Calorimetric Study. Macromolecules 1983, 16, 732–736.   TOC figure