Electronic and structural effects on the nonlinear optical behavior in π-conjugated structure bis(4-nitrophenyl) carbonate: a vibrational spectroscopic approach

Fourier transform (FT)-Raman and infrared (IR) spectra of the nonlinear optical (NLO) material bis(4-nitrophenyl) carbonate were recorded and analyzed. The geometry, first hyperpolarizability and harmonic vibrational wavenumbers were calculated with the help of Becke3-Lee-Yang-Parr density functional theory method. The detailed interpretation of the vibrational spectra was carried out with the aid of normal coordinate analysis following the scaled quantum mechanical force field methodology. The second-order NLO properties of the molecule were studied by the Kurtz and Perry powder reflection technique. Stability of the molecule arising from hyperconjugative interactions leading to its NLO activity and charge delocalization were analyzed using natural bond orbital analysis. Copyright (C) 2010 John Wiley & Sons, Ltd.