DFT study of the Jahn–Teller effect in Cu(II) chelate complexes

Abstract

Density functional theory (DFT) in conjunction with the intrinsic distortion path (IDP) is employed to study the Jahn–Teller (JT) effect in all four diastereoisomers of tris(ethylenediamine)copper(II) ( [ Cu ( en ) 3 ] 2 + ) and tris(ethyleneglycol)copper(II) ( [ Cu ( eg ) 3 ] 2 + ) complexes. As a consequence of the JT effect all the isomers tetragonally elongate to the C 2 configurations. Although there are energy differences between the isomers of [ Cu ( en ) 3 ] 2 + , almost equal JT parameters suggest that chelate ring conformation does not have affect on the JT distortion. In a case of [ Cu ( eg ) 3 ] 2 + JT effect causes additional hydrogen bond formation and these two effects define the overall geometry of isomers.