DFT studies and vibrational spectra of trans 1,2-bis(4-pyridyl)ethylene and its zinc(II)halide complexes

The geometry, frequency and intensity of the vibrational bands of trans 1,2-bis(4-pyridyl)ethylene (which is abbreviated as bpe) were obtained using the density functional theory (DFT) with the BLYP, B3LYP, B3PW91 functionals and 6-311G* basis set

HF and DFT studies and vibrational spectra of 1,2-bis(2-pyridyl) ethylene and its zinc (II) halide complexes

Ab initio restricted Hartree-Fock and density function theory calculations using BLYP, B3LYP and B3PW91 functionals were carried out to study molecular structure and vibrational spectrum of 1,2-bis(2-pyridyl)ethylene (which is abbreviated as bpe). Comparison of calculated and experimental results indicates the density functional B3LYP and BLYP/6-311G* methods are more accurate in predicting fundamental vibrational frequencies than the scaled other approaches. On the basis of calculated results, assignment of fundamental vibrational modes of bpe was proposed. Complexes of the type Zn(bpe)X-2 [where X = Cl, Br, I] have been studied in the 4000-400 cm(-1) region, and assignments of all the observed bands were made. The analysis of the infrared spectra indicates that there is some structure-spectra correlations