Electronic structure and nonlinear optical properties of model push–pull polyenes with modified indanone groups: a theoretical investigation
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- 作者：Szymusiak ; Henryk ; Zielinski ; Ryszard ; Domagalska ; Beata W. ; Wilk ; Kazimiera A.
- 关键词：Bond length alternation ; Global softness ; Polarizability ; Hyperpolarizability ; Quantum-chemical calculations ; Raman spectra of conjugated polyenes with indanone moiety
- 刊名：Computers and Chemistry
- 出版年：2000
- 出版时间：May, 2000
- 年：2000
- 卷：24
- 期：3-4
- 页码：369-380
- 全文大小：285 K
文摘
Several model polyenes with modified indanone groups were studied by means of density functional theory (DFT) B3LYP/6-31G*, ab initio HF/3-21G* and semiempirical AM1 methods. We investigated the effect of several substituents upon the relationship between the structure, spatial distribution of the highest occupied and the lowest unoccupied π-MOs, a concept of the global softness and the global hardness as well as both linear and nonlinear polarizabilities for the set of π-electron chromophores represented by the short-chain model polyene (butadiene) carrying out p-methoxyphenyl group on the one end and several modified indanone groups on the opposite end of the molecule. As probing endocyclic groups used to modify the structure of indanone the following substituents: >CH2; >C
O; >SO2, >CCH(NO2) and >CC(CN)2 were selected. The cubic relationship between the polarizability and the global softness was found. The highest polarizabilities (α, β, γ) are predicted for the derivatives with >CC(CN)2 group. It was found that the value of β depends mainly on the difference between dipole moments in the excited and ground states of the molecules. In the case of >SO2 group the results of AM1 calculations significantly deviate from relationships found for other derivatives. Experimental IR and Raman spectra of newly synthesized indandione derivative of cinnamaldehyde were compared with computed ones.
O; >SO2, >CCH(NO2) and >CC(CN)2 were selected. The cubic relationship between the polarizability and the global softness was found. The highest polarizabilities (α, β, γ) are predicted for the derivatives with >CC(CN)2 group. It was found that the value of β depends mainly on the difference between dipole moments in the excited and ground states of the molecules. In the case of >SO2 group the results of AM1 calculations significantly deviate from relationships found for other derivatives. Experimental IR and Raman spectra of newly synthesized indandione derivative of cinnamaldehyde were compared with computed ones.