Work

Conformation‐Dependent Luminescence and Thermal Phase Transition of Crystals of a Tetrahydropentalene Derivative Bearing Aromatic Rings with Frustrated Free Rotation

Year: 2025

Type: article

Abstract: Results of a study exploring the solid‐state photoluminescence properties of two crystalline polymorphs ( O ‐form (orange prisms) and R ‐form (red prisms)) of 1,4‐bis(dicyanomethylidene)‐2,2,5,5‐tetramethyl‐3,6‐bis(4‐methoxyphenyl)‐1,2,4,5‐tetrahydropentalene ( BTP‐An ) are reported. The O ‐form was found to display more quantum‐efficient photoluminescence in a shorter‐wavelength region compared to that of the R ‐form . X‐ray crystallographic analysis suggests that a unique conformation with largely rotated 4‐methoxyphenyl (anisyl) groups and suppression of free rotation of the dicyanomethylene groups are likely responsible for the shorter wavelength and higher quantum yield for photoluminescence from the O ‐form . Also, the thermally metastable O ‐form undergoes a phase transition to generate the R ‐form upon either heating or exposure to organic solvent vapors.

Source: Asian Journal of Organic Chemistry

DOI: 10.1002/ajoc.202500510

Authors: Tomoki Nagaoka, Yasunori Matsui, Takuya Ogaki, Hiroyoshi Naito, Hiroshi Ikeda

Institution: Osaka Metropolitan University

Language: English

Topic: Luminescence and Fluorescent Materials

Subfield: Materials Chemistry

Field: Materials Science

Domain: Physical Sciences

Open Access status: green

Funders: Konica Minolta Imaging Science Foundation, Mayekawa Houonkai Foundation, Japan Society for the Promotion of Science