EXCIMER FORMATION KINETICS IN LIQUID-CRYSTALLINE ALKYLCYANOBIPHENYLS

被引：78

作者：

IKEDA, T

KURIHARA, S

TAZUKE, S

机构：

[1] Photochemical Process Division, Research Laboratory of Resources Utilization, Tokyo Institute of Technology, Midori-ku, Yokohama 227

来源：

JOURNAL OF PHYSICAL CHEMISTRY | 1990年 / 94卷 / 17期

关键词：

D O I：

10.1021/j100380a008

中图分类号：

O64 [物理化学（理论化学）、化学物理学];

学科分类号：

070304 ; 081704 ;

摘要：

Excimer formation kinetics of three 4-cyano-4′-alkylbiphenyls (nCB) (alkyl = pentyl (5CB), hexyl (6CB), and octyl (8CB)) were studied by steady-state and time-resolved fluorescence spectroscopy. Excimer formation was significantly enhanced in nematic (N) state compared with isotropic (I) state but depressed in the smectic A (SA) state, although orientational ordering of mesogens in the SA state is much higher than in the N state. Time-resolved fluorescence spectra demonstrated the existence of the ground-state association of mesogens in the N phase, which produced excimer directly on excitation. Kinetical analysis of the excimer formation on the basis of a model that included the ground-state association of the mesogenic chromophores revealed that the rate constants of excimer formation and dissociation in nCB showed discrete change at temperatures close to the N-I phase transition temperatures. © 1990 American Chemical Society.

引用

页码：6550 / 6555

页数：6

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