Theoretical investigation of the [1,5]-hydrogen shift in (Z)-1,3-pentadiene with a density functional theory computational approach

The results of computing the transition state for the 1,5-hydrogen shift of 1,3-pentadiene isomerization with AM1 semiempirical and three of the most widely used DFT methods (B3LYP, BLYP, and SVWN) are discussed. The isomerization threshold was computed with DFT methods on both AM1 and DFT geometries. The computed values are compared with experimental data and the suitability of a DFT/AM1 approach to compute the 1,5-hydrogen shift isomerization reaction is discussed. (C) 1998 Elsevier Science B.V.