Density functional theory study on the structure and vibrational spectra for 4-methyl-3-pentene-2-one

Density functional theory BLYP (using Becke's and Lee-Yang-Parr's correlation functionals), ab initio Hartree-Fock (HF) and hybrid DFT/HF B3LYP calculations were carried out to study the structure and vibrational spectra of s-cis-4-methyl-3-pentene-2-one. Molecular conformation calculations were made for four possible conformers of the compound using the HF and BLYP methods. Calculated results show that: (1) the stable conformer of the 4-methyl-3-penten-2-one is s-cis; (2) the BLYP/6-31G* and scaled HF/6-31G* frequencies correspond well with each other and with available experimental assignment of the normal vibrational modes. (C) 2000 Elsevier Science B.V. All rights reserved.