Photochemical properties of carotenoids: what can we get from the VB model?  

作　　者：高嶷 刘春根 江元生 

机构地区：[1]Institute of Mesoscopic Chemistry and Material, Department of Chemistry, Nanjing University, Nanjing 210093, China

出　　处：《Science China Chemistry》2003年第1期7-12,共6页中国科学（化学英文版）

基　　金：Part of the computational work was done on the SGI Origin 3800 and Dawning 3000 supercom-puters at Nanjing University. This work was supported by the National Natural Science Foundation of China (Grant Nos. 20073020 and 20273030).

摘　　要：The empirical valence bond model, solved by the DMRG technique, is applied to the systematical study of the photochemical processes of carotenoids. The polyenes with five up to one hundred of C== C bonds are investigated. The probability of the state arrangement for the conjugated bond, Pij, is evaluated. It is a parameter to correlate the bond lengths, and could also be applied to rationalizing the quantum yields of the photo-isomerization and the reaction constant of the quenching of singlet-oxygen happened to the external C== C bond of the carotenoids. The maximum reaction constant in long chain limit is determined as about 2.92×1010 L·mol-1·s-1.The empirical valence bond model, solved by the DMRG technique, is applied to the systematical study of the photochemical processes of carotenoids. The polyenes with five up to one hundred of C=C bonds are investigated. The probability of the state arrangement for the conjugated bond, P ij is evaluated. It is a parameter to correlate the bond lengths, and could also be applied to rationalizing the quantum yields of the photo-isomerization and the reaction constant of the quenching of singlet-oxygen happened to the external C=C bond of the carotenoids. The maximum reaction constant in long chain limit is determined as about 2.92×1010 L · mol-1 ·s -1

关 键 词：Pij   SINGLET oxygen quenching  cis-trans isomerization  DMRG. 

分 类 号：O629[理学—有机化学]