First-Principles Determinations and Investigations of the Electronic Absorption and Third-Order Polarizability Spectra of Electron Donor-Acceptor Chromophores Tetraalkylammonium Halide/Carbon Tetrabro

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• 作者：Juan Shen ; Wen-Dan Cheng ; Dong-Sheng Wu ; Shu-Ping Huang ; Hui Hu ; Zhi Xie
• 刊名：Journal of Physical Chemistry A
• 出版年：2007
• 出版时间：September 27, 2007
• 年：2007
• 卷：111
• 期：38
• 页码：9249 - 9254
• 全文大小：253K
• 年卷期：v.111,no.38(September 27, 2007)
• ISSN：1520-5215

文摘

Calculations on donor-acceptor molecular pairs of tetraalkylammonium halide/carbon tetrabromide complexesare provided to investigate structure/property-related linear and nonlinear optical properties by using the time-dependent density functional theory technique coupled with the sum-over-states method. The calculated energiesof the first allowed electronic transition decrease, and the nonresonant third-order polarizabilities at the THG,EFISHG, and DFWM optical processes increase progressively from [DBU-H⁺Br^-·CBr₄] to [NPr₄Br·CBr₄]to [NMe₄Br·CBr₄]. The obtained electronic absorption spectra show a progressive red shift with increasingdonor strength from Cl to I for [NR₄h·CBr₄] (h = Cl, Br, and I). The charge transfers from the halogen donorto the carbon tetrabromide acceptor make significant contributions to the electronic absorption spectra in thelow-energy zone and the third-order polarizabilities in the nonresonant frequency region. The counterionindirectly affects the electronic absorption and third-order polarizability spectra through the interactions betweenthe donor and acceptor.