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用飞秒Ti:sapphire激光测定了星型二苯乙烯衍生物2,5-二{4-{2-N,N-二[4-(2-N,N-二苯基氨基苯乙烯基)苯基]氨基苯乙烯基}苯基}-1,3,4-噁二唑(DPASPO)和1,2,4,5-四(4-N,N-二苯氨基苯乙烯基)苯(PASB)的三光子吸收谱和多光子上转换荧光光谱.研究了星形八极矩分子DPASPO和PASB的线性吸收、单光子荧光及荧光寿命.在800nm波长的飞秒激光激发下,DPASPO和PASB在二氯甲烷溶液中发出很强的黄绿色双光子上转换荧光,荧光峰分别位于583nm和547nm.在1260nm波长的飞秒激光激发下,DPASPO和PASB的三光子上转换荧光峰分别位于612nm和572nm.采用非线性透过率法测得DPASPO和PASB最大三光子吸收截面分别为16.69×10-79cm6·s2和6.81×10-79cm6·s2.这些二苯乙烯衍生物的三光子吸收截面较大.在这些星型分子中,三光子吸收增强来源于二苯乙烯分支的增加,共轭体系的扩展以及分子内跨越空间电荷离域.
The stilbene derivative 2,5-bis {4- {2-N, N-bis [4- (2-N, N-diphenylaminostyryl) Phenyl] aminostyryl} phenyl} -1,3,4-oxadiazole (DPASPO) and 1,2,4,5-tetrakis (4-N, N-diphenylaminostyryl) benzene PASB) and multi-photon up-conversion fluorescence spectra, the linear absorption, single-photon fluorescence and fluorescence lifetime of star octupole molecules DPASPO and PASB were studied.Using femtosecond laser excitation at 800 nm, DPASPO and PASB In dichloromethane solution, a strong yellow-green two-photon upconversion fluorescence was emitted with the fluorescence peaks at 583nm and 547nm, respectively. Under the excitation of 1260nm femtosecond laser, the up-conversion fluorescence peaks of DPASPO and PASB were at 612nm and 572nm.The maximum three-photon absorption cross sections of DPASPO and PASB measured by the nonlinear transmittance method are 16.69 × 10-79cm6 · s2 and 6.81 × 10-79cm6 · s2 respectively.These three-photon absorption cross-sections of these stilbene derivatives are larger In these star molecules, the enhanced three-photon absorption results from an increase in the stilbene branching, the extension of the conjugated system, and the spatial delocalization within the molecule.