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Vapochromism and Crystallization-Enhanced Emission of 1,1-Disubstituted 2,3,4,5-Tetraphenylsiloles

2007; Springer Science+Business Media; Volume: 17; Issue: 4 Linguagem: Inglês

10.1007/s10904-007-9152-1

1574-1451

Yongqiang Dong, Jacky W. Y. Lam, Anjun Qin, Zhen Li, Jing Zhi Sun, Yuping Dong, Ben Zhong Tang,

Radical Photochemical Reactions

Effects of solvent vapor on the photoluminescence (PL) of 2,3,4,5-tetraphenylsiloles carrying different 1,1-substituents [(PhC)4SiRR′, R = Ph, R′ = CH3 (2); R = Ph, R′ = C≡CH (3); R = R′ = C≡CH (4)] were investigated. The emission of the silole spots on the TLC plates can be turned "off" and "on" continuously and reversibly by wetting by, and de-wetting from, vapors of organic solvents, respectively. After fumigation by solvent vapor, the thin film of 4 coated on the quartz substrate emits stronger and bluer PL owing to the transformation of film morphology from the amorphous to the crystalline phase. Analysis by X-ray diffraction reveals that the molecular conformations of the crystals of 2–4 are locked and stabilized by multiple C–H···π hydrogen bonds. This structural rigidification has made the silole crystals stronger emitters.