2-[（4'-N，N-二甲胺基）苯乙烯基]-5-二米基硼-噻吩的合成-结构与光物理性质

合成了以含硼（III）基团为电子受体，以二甲胺基为电子给体，以苯乙烯基 噻吩为共轭桥的新化合物2-（4'-N，N-二甲胺基）苯乙烯基]-5-二米基硼-噻吩 trans-2-(4'-N, N-dimethylamino) styryl]-5-dimesitylboryl-thiophene（简 写为DMASBT，5）。X射线衍射方法测定其单晶结构表明，硼原子与π共轭桥之间的 硼碳键相对于其它的硼碳键明显缩短，硼与π共轭桥之间存在除了σ键之外的p-π 共轭作用。研究了它在不同溶剂中的光物理性质，发现它具有突出的溶致变色效应 。在极性较大的溶剂中，有较高的荧光量子产率和较长的荧光寿命。激光实验发现 ，DMASBT在近红外波段（750～850 nm）有较强的非线性吸收，用波长为800 nm的 红色飞秒激光激发时，DMASBT在四氢呋喃中发现波长为559 nm的强的绿色上转换荧 光。

Synthesis, Structure and Photo-Physical Property of trans-2-[(4'-N, N-dimethylamino) styryl]-5-dimesitylborylthiophene

A new organic compound, trans-2-( A'-N, iV-dimethylamino ) styryl ] -5-dimesitylborylthiophene (abbreviated as DMASBT, 5) with dimesitylboryl, dimethylamino and styryl-thiophene as electron acceptor, electron donor and conjugate bridge respectively, was synthesized. Its crystal structure determined by X-ray diffraction method indicates that the B-C bond between B atom and it bridge is obviously shorter than those of between B atom and mesityl groups. This remarkably strengthened B-C bonding can be regarded as an evidence of additional p-7t conjugation between the B atom and n bridge. The photo-physical properties of 5 in various solvents were studied in details. With the increasing of the polarity of solvents, the emission band of 5 will be remarkably red-shifted, its quantum yield will be increased and the lifetime will be lengthened. 5 Shows strong nonlinear absorption in the NIR band (750 ~ 850 nm) in the laser experiments in THF solution. Especially when it was irradiated by a femto-second laser at 800 nm, a strong up-converted green fluorescence in THF was observed.