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Molecular Packing and Solid‐State Photophysical Properties of 1,3,6,8‐Tetraalkylpyrenes
Author(s) -
Iwasaki Takanori,
Murakami Shin,
Takeda Youhei,
Fukuhara Gaku,
Tohnai Norimitsu,
Yakiyama Yumi,
Sakurai Hidehiro,
Kambe Nobuaki
Publication year - 2019
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.201903224
Subject(s) - alkyl , pyrene , excimer , chromophore , solid state , fluorescence , quantum yield , photochemistry , crystal (programming language) , chemistry , crystallography , materials science , organic chemistry , optics , physics , computer science , programming language
The relationship between the photophysical properties and molecular orientation of 1,3,6,8‐tetraalkylpyrenes in the solid state is described herein. The introduction of alkyl groups with different chain structures (in terms of length and branching) did not affect the photophysical properties in solution, but significantly shifted the emission wavelengths and fluorescence quantum yields in the solid state for some samples. Pyrenes bearing ethyl, isobutyl, or neopentyl groups at the 1‐, 3‐, 6‐, and 8‐positions showed similar emission profiles in both the solution and solid states. In contrast, pyrenes bearing other alkyl groups exhibited an excimer emission in the solid state, similar to that of the parent pyrene. On studying the photophysical properties in the solid state with respect to the obtained crystal structures, the observed solid‐state photophysical properties were found to depend on the relative position of the pyrene chromophores. The solid‐state photophysical properties can be controlled by the alkyl groups, which provide changing crystal packing. Among the pyrenes tested, 1,3,6,8‐tetraethylpyrene showed the highest fluorescence quantum yield of 0.88 in the solid state.