摘要
本文设计合成了两个典型的共轭的电子给体与电子受体(D-A)化合物:2-三氰基乙烯基蒽(2-TCVA)与9-三氰基乙烯基蒽(9-TCVA),通过极性效应,温度效应对它们基态与激发态的光谱行为进行了表征。研究表明:这两个化合物均表现出显著的电荷转移(CT)吸收峰,分子受光激发后,9-TCVA只能在非极性溶剂中产生分子内电荷转移(ICT)态荧光,而2-TCVA在极性与非极性溶剂中都能从ICT态发光.另外,温度效应显示冻结态下,2-TCVA只发射ICT态荧光,而9-TCVA既发射类蒽(anthracene-like)荧光又发射ICT态荧光,造成这一现象的主要原因可能是2-TCVA与9-TCVA分子平面性上的差异而引起分子内电荷转移相互作用不同所致。文中还利用了Bilot-Kawski公式估算了化合物2-TCVA在激发态与基态时偶极矩的差值为18.8D。
Two conjugating electron donor-acceptor(D-A)compounds, 2-tricyanovinyl anthracene(2-TCVA)and 9-tricyanovinyl anthracene(9-TCVA), were synthesized and their spectroscopic properties in a series of solvents with different polarity and at different temperature were studied.The results reveal that the structure of 2-TCVA is more planar than 9TCVA at their ground state and the charge transfer bands show up in their absorption spectra.Fluorescence emits from intramolecular charge transfer(ICT)state for 9-TCVA in nonpolar solvents,while for 2-TCVA in both polar and non-polar solvents. When the molecule was freezed,2-TCVA emits fluorescence from its ICT state,while 9-TCVA emits dual fluorescence from its local and ICT state,due to the structure of 2-TCVA is more planar than 9-TCVA. The dipole moment difference between excited state and ground state for 2-TC-VA was estimated as 18.8 D.
出处
《感光科学与光化学》
CSCD
1996年第2期108-114,共7页
Photographic Science and Photochemistry
基金
国家自然科学基金
国家科学技术委员会基础性研究重大课题
关键词
吸收光谱
荧光光谱
三氰基乙烯基蒽
intramolecular charge transfer, charge separation, spiral conjugation