摘要
以二米基硼为电子受体,苯乙烯基噻吩为共轭桥,合成了两个新的稳定的有机硼化合物:反式,反式-2-二米基硼-5-{2-[4-(2-噻吩乙烯基)苯基]乙烯基}噻吩(1)和反式,反式-1,4-二-[2-(5-二米基硼噻吩)乙烯基]苯(2).前者为不对称结构的偶极分子,后者为对称的A-π-A型四极分子.对称性不同的化合物表现出不同的双光子吸收性质.对于偶极分子1.单双光子吸收达到的激发态能级接近,而对于四极分子2,双光子吸收达到的激发态则比单光子吸收所达到的激发态高出0.35 eV.在波长为710到900 nm范围的飞秒脉冲激光激发下,化合物1和2在THF溶液中都可以发出很强的绿色上转换荧光(1,λmax=505 nm;2,λmax=513 nm)).用双光子荧光法测得A-π-A型化合物2在775 nm处的双光子吸收截面达1340GM.
Two new stable organoboron compounds with dimesitylboryl group as electron acceptor and styrylthiophene as conjugated bridge have been synthesized, which are named trans,trans-2-dimesityl-boryl-5-（2-（4-（2-（thien-2-yl）vinyl）phenyl）vinyl）thiophene （1） and trans,trans-1,4-bis[2-（5-dimesitylboryl-thien-2-yl）vinyl]benzene （2）. The former is asymmetrical dipolar molecule and the latter is symmetrical A-π-A type quadrupolar molecule. The compounds with different symmetry exhibit different two-photon absorption properties. To dipolar molecule 1, the energy levels of the excited states by single- and two-photon absorption processes are very close, but to quadrupolar molecule 2, the level of the excited state by two-photon absorption is about 0.35 eV higher than that by single-photon absorption. Pumped by laser pulses from 710 to 900 nm in femtosecond regime, both compounds 1 and 2 showed strong green up-converted fluorescence in THF solution with λmax=505 nm for 1 and λ=513 nm for 2. Under the excitation of 775 nm light, the two-photon absorption cross-section of 2 was measured to be 1340 GM by two-photon fluorescence method.
出处
《化学学报》
SCIE
CAS
CSCD
北大核心
2005年第15期1415-1420,共6页
Acta Chimica Sinica
基金
国家自然科学基金(Nos.20472044
20172034)高等学校骨干教师资助计划资助项目.
