# Harnessing inhomogeneous π-aggregates: a new path to optical modulation in methyl salicylate-based solvent-free liquids

https://mdr.nims.go.jp/datasets/815e830e-7ec8-46bb-9a8f-9828d6629209

## File

- [Chem Sci_D5SC06148B_Accepted Article.pdf](https://mdr.nims.go.jp/filesets/f772af80-13de-4b58-84e2-f9c4cd2363f7/download) ([Detail](https://mdr.nims.go.jp/filesets/f772af80-13de-4b58-84e2-f9c4cd2363f7.md))

## Id

815e830e-7ec8-46bb-9a8f-9828d6629209

## Local identifier



## Visibility

open_to_public

## State

published

## Created at

2025-11-26T12:50:54.090828Z

## Updated at

2025-11-27T23:30:07.937575Z

## Published at

2025-11-27T23:22:40.419977Z

## Doi

https://doi.org/10.48505/nims.5931

## First published url

https://doi.org/10.1039/d5sc06148b

## Date published

2025-10-22

## Recorded date published

2025-11-26

## Resource type

journal_article

## Manuscript type

accepted_manuscript

## Collection



## Title

- title: 'Harnessing inhomogeneous π-aggregates: a new path to optical modulation
    in methyl salicylate-based solvent-free liquids'
  title_type: original
  lang: en

## Description

- description: We found that methyl salicylate (MS), a colourless liquid, transforms
    into a vivid yellow liquid with distinct absorption and fluorescence spectral
    characteristics when an alkoxy chain with a carbon number of four to seven is
    attached to the 5-position of MS. This phonomenon suggests the presence of microscopic
    local structures in the liquids, where π-electrons are delocalized across multiple
    MS molecules. X-ray diffraction (XRD) measurements supported this interpretation
    by indicating aggregates in the 10–15 Å range, composed of about three to five
    MS molecules arranged in a face-to-face π-stacking configuration. When the alkylated
    MS liquids are heated from temperatures below their glass transition temperature,
    they exhibit the property of crystallizing from a supercooled liquid state, known
    as cold crystallization. Furthermore, free-volume analysis using positron annihilation
    lifetime spectroscopy (PALS) suggested that the yellow liquids have fewer free-volume
    regions compared to the unsubstituted MS colourless liquid. Consistent with these
    findings, time-resolved fluorescence spectroscopy of the neat yellow liquids revealed
    a relatively longer lifetime of 20 ns, which is likely attributable to fluorescence
    from π-aggregates, distinct from the 0.5 ns shorter lifetime component observed
    for single molecules in diluted solutions. All of these results support the presence
    of π-aggregates, which contribute to the colour and fluorescence of the liquids.
    Supramolecular aggregates in liquids have been studied both experimentally and
    theoretically; however, the alkoxylated MS liquids represent the first example
    in which they significantly affect the optical properties of the liquids.
  description_type: abstract
  lang: und

## Creator

- name: Kei Kobayashi
  role: author
  orcid: https://orcid.org/0009-0000-1619-7723
- name: Ken-ichi Sakai
  role: author
  orcid: https://orcid.org/0000-0002-4479-6421
- name: Tomoyuki Akutagawa
  role: author
  orcid: https://orcid.org/0000-0003-3040-1078
- name: Takashi Nakanishi
  role: author
  orcid: https://orcid.org/0000-0002-8744-782X

## Contact agent



## Publisher

organization: Royal Society of Chemistry (RSC)

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## Keyword

- subject: Solvent-free liquids
  schema: not_defined
- subject: Inhomogeneous π-aggregates
  schema: not_defined
- subject: Methyl salicylate
  schema: not_defined
- subject: Fluorescence
  schema: not_defined
- subject: Supercooled liquid state
  schema: not_defined

## Rights

- identifier: cc-by-3.0

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## Embargo



## Journal

- title: Chemical Science
  issn: '20416520'
  volume: '16'
  issue: '46'
  start_page: 21797
  end_page: 21805

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## Related item



## Funding

- funder_name: Takahashi Industrial and Economic Research Foundation
- identifier: KAKENHI, Grant No. 25K0870, Category C
  funder_name: Ministry of Education, Culture, Sports, Science and Technology
- identifier: 2024-49
  funder_name: National Institute for Materials Science
  description: NIMS連携拠点推進制度

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## Fileset

- id: f772af80-13de-4b58-84e2-f9c4cd2363f7
  filename: Chem Sci_D5SC06148B_Accepted Article.pdf
  content_type: application/pdf
  size: 1024251
  md5: b41685cb17aabf1bc45f25f3a8f2d5c1

## Thumbnail

fileset_id: f772af80-13de-4b58-84e2-f9c4cd2363f7
filename: Chem Sci_D5SC06148B_Accepted Article.pdf