期刊
CHEMICAL PHYSICS
卷 279, 期 2-3, 页码 179-207出版社
ELSEVIER
DOI: 10.1016/S0301-0104(02)00384-1
关键词
two-photon absorption; two-photon fluorescence; two-photon states; vibronic coupling; squaraines; oligomers; structure-property relationships; exciton coupling
The excited states of novel monomeric and oligomeric squaraines of the indole series were studied by two-photon fluorescence (TPF). Two-photon excitation scans have been performed in an energy range from 1.75 to 3.2 eV by linearly and circularly polarized light. In addition, results from linear absorption and fluorescence measurements are presented. For the monomers a two-photon transition into the first excited state (B-u-symmetry) allowed by vibronic coupling was found. The interpretation of this transition is different to results of other groups. A second transition to an electronic state in an energy range of 2.5-3.5 eV was observed experimentally for the first time. The optical properties of this 2A(g) state strongly depend on the molecular structure. The experimental results are compared to a four-state model. It is shown theoretically and experimentally that both, the linear absorption and the two-photon spectra of squaraine oligomers can be explained by a state interaction between excitons localized at the monomeric subunits (exciton coupling theory). (C) 2002 Elsevier Science B.V. All rights reserved.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据