共轭烯烃的共轭极化势  

Conjugated Polarizability Potential of Conjugated Alkenes

作　　者：曹晨忠[1] 林原斌[2] 

机构地区：[1]湖南科技大学化学化工学院,湘潭411201 [2]湘潭大学化学学院,湘潭411105

出　　处：《Chinese Journal of Chemical Physics》2004年第6期703-710,共8页化学物理学报（英文）

基　　金：ProjectsupportedbytheNationalNaturalScienceFoundationofChina (2 0 172 0 4 3)andHunanProvinceEducationCommission .

摘　　要：从共轭极化出发 ,以共轭极化过程的双极态静电能的平均值与非极态静电能的差值作为共轭极化势(CPP) .用共轭极化势与共轭烯烃紫外吸收最大波长的能量相关 ,用量子化学从头计算得到的前线轨道能量与其紫外吸收最大波长的能量进行相关 ,得到前者与后者相近的结果 .进一步以有效极化效应PEI(ef)来定量烷基极化效应对共轭烯烃双极态的稳定作用 ,并以CPP和PEI(ef)两个变量与共轭烯烃紫外吸收最大波长的能量相关 ,得到具有良好预测能力的定量方程 :ν =1.174 6 +5 .0 187CPP - 0 .4 32 0 4PEI(ef) ,R =0 .9995 ,s =0 .0 4 0 3,F =10 85 3.2 8,n =2 3研究结果还表明 ,依靠增加取代基数量的方法来降低紫外吸收能量不及增加共轭链的长度有效 .Based on the conjugated polarization theory, it is expressed as the conjugated polarizability potential (CPP) that the discrepancy between the average electrostatic energy of dipolar state and the electrostatic energy of non-polar state in the conjugated polarizability procedure for the conjugated alkenes. The correlation between CPP and the energy of ultraviolet absorption maximum, and the correlation between the energy of frontier molecular orbital obtained by ab initio calculation of quantum chemistry and the energy of ultraviolet absorption maximum have been carried out for the conjugated alkenes. Both correlation equations show a similar estimated precision. Further, the contribution of alkyl polarizability effect to the stability of dipolar state for the alkyl substituted alkenes with the effective polarizability effect index (PEI(ef)) was quantified. Relating the above two parameters CPP and PEI(ef) to the energy of ultraviolet absorption maximum of the substituted alkenes in a two-parameter expression with a good prediction ability was obtained: ν=1.1746+5.0187CPP-0.43204PEI(ef), R=0.9995, s=0.0403, F=10853.28, n=23The investigated results also indicate that it is less effective to reduce the energy of ultraviolet absorption maximum by means of increasing the alkyl substituent groups than lengthening the conjugated backbone chain in the conjugated alkenes.

关 键 词：共轭极化 烯烃 共轭极化势 紫外光谱 有效极化效应 

分 类 号：O621.12[理学—有机化学]