Theoretical Studies on the Ground and Excited States of a Series of Organoboron Quinolinolates with Extended Conjugated Chromophores

• 来源期刊: 中国化学（英文版）
• 年，卷（期）: 2008,（11）
• 页码范围: 1979-1984
• 页数: 6页
• 语种: 英文

摘要

It has been reported in literature that a series of luminescent materials(Ph2Bq-x2)[x2=5,7-dibromo(1);5,7-diphenyl(2);5,7-bis(biphenyl-4-yl);5,7-bis(9,9-dihexylfluoren);q=8-quinolinelate] have been synthesized and investigated.The results showed that the strongest absorption peaks were significantly red-shifted upon the exten-sion of the n-conjugation length of substituents.Here,di(p-nitrostyryl)(3)and distyryl(4)were introduced to re-place bis(biphenyl-4-yl)and bis(9,9-dihexylfluorenyl),respectively.Density functional theory and time-dependent density functional theory were used to investigate and compare the electronic and spectral properties of complexes 1 to 4.The calculated results reveal that the two simple suhstituents can also make the absorption peaks rod-shifted following 1 and 2.Furthermore,3 and 4 have larger oscillator strength at the positions of absorption peaks than those of 1 and 2,which will increase the transition probability of electrons from the ground state to the excited state.This higher transition probability to the excited state means the greater emission probability.