THEORETICAL STUDIES OF ROTATIONAL BARRIERS OF DITHIOCARBAMATE LIGANDS IN THE SQUARE PLANAR COMPLEXES TM(L)(L')(H2DTC) (TM=IR, RH)

Abstract Rotational barriers of dithiocarbamate ligands in the four-coordinate complexes TM(L)(L′)(H 2 dtc) (TM=Ir, Rh; L=L′=CO, PH 3 , NH 3 ; L=CO, L′=PH 3 ) have been investigated by density functional theory calculations at the B3LYP level. The effects of L and L′ ligands, and transition metals on the barriers have been examined. The results show that the rotational barriers decrease with L and L′ from having π-acceptor to σ-donor properties. In general, the rotational barriers for Ir complexes slightly change in comparison to those of the Rh analogues. This result indicates that the central metal has slightly effect on this rotation and, it is modified by the electronic properties of L and L′.