First-principles determinations and investigations of the electronic absorption and third-order polarizability spectra of electron donor-acceptor chromophores tetraalkylammonium halide/carbon tetrabromide.
Calculations on donor-acceptor molecular pairs of tetraalkylammonium halide/carbon tetrabromide complexes are 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 energies of 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-.CBr(4) to [NPr(4)Br.CBr(4)] to [NMe(4)Br.CBr(4)]. The obtained electronic absorption spectra show a progressive red shift with increasing donor strength from Cl to I for [NR(4)h.CBr(4)] (h = Cl, Br, and I). The charge transfers from the halogen donor to the carbon tetrabromide acceptor make significant contributions to the electronic absorption spectra in the low-energy zone and the third-order polarizabilities in the nonresonant frequency region. The counterion indirectly affects the electronic absorption and third-order polarizability spectra through the interactions between the donor and acceptor.
State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, the Chinese Academy of Sciences, Fuzhou, Fujian 350002, People's Republic of China.
Juan
J
Shen
Wen-Dan
WD
Cheng
Dong-Sheng
DS
Wu
Shu-Ping
SP
Huang
Hui
H
Hu
Zhi
Z
Xie