文献类型：期刊文献

英文题名：The effect of heteroatoms and end groups of polymethines on the all-optical switching processing application: a CC2 calculation

作者：Wang, Chao[1,2];Yuan, Yizhong[1,2];Tian, Xiaohui[1,2];Yuan, Jianyong[1,2];Sun, Jinyu[1,2]

机构：[1]East China Univ Sci & Technol, Sch Mat Sci & Engn, Minist Educ, Key Lab Ultrafine Mat, Shanghai 200237, Peoples R China;[2]East China Univ Sci & Technol, Sch Mat Sci & Engn, Shanghai Key Lab Adv Polymer Mat, Shanghai 200237, Peoples R China

年份：2016

卷号：27

期号：4

起止页码：1211

外文期刊名：STRUCTURAL CHEMISTRY

收录：;EI(收录号：20242616451221);WOS:【SCI-EXPANDED(收录号:WOS:000379983100018)】；

基金：This research was supported by the Fundamental Research Funds for the Central Universities (22A201514002), Shanghai leading academic discipline project (No. B502), Shanghai key laboratory project (No. 08DZ2230500). We thank Georgia Institute of Technology for the computer resources.

语种：英文

外文关键词：AOSP; Polymethines; CC2; Structural-properties relationship

摘要：The structure-properties relationship of heterocyclic polymethines on the all-optical switching processing (AOSP) is studied by CC2 method. In particular, the excitation energies of the first and second excited states (E (ge) and E (ge') ) and the corresponding ratio (R (ee') = E (ge') /E (ge), energy window width) are evaluated. The comparable energy gap between HOMO and HOMO - 1 (pi type) and between LUMO and LUMO + 1 (pi* type) is the key in keeping R (ee') large. Moreover, only a significant increase of such energy gap can result in the increase in R (ee') because the energy gap is a poor description of excitation energy. The results show that the heavy heteroatoms decrease the E (ge) and E (ge') as expected compared to light atoms such as carbon. For five-membered heterocyclic polymethines and their derivatives (two heteroatoms in total), the R (ee') is stable around 1.7 reflecting the nature of this system: The additional heteroatoms have little effects on the width of energy window. In the case of six-membered heterocyclic polymethines and their derivatives, the decrease in excitation energy is more effective compared to the former due to the relative large effective length of the end group, which can thus help avoiding the symmetry breaking. The effect of heteroatoms on R (ee') is clear that it helps keeping the energy window open compared to carbon atom. The heavier the heteroatom is, the higher R (ee') value will be when it is on the ortho position. Consequently, at least one heteroatom is necessary on the design of polymethines for AOSP application.