Theoretical studies of inorganic and organometallic reaction mechanisms. 2. The trans effect in square-planar platinum(II) and rhodium(I) substitution reactions

TLDR: In this paper, a pseudo-trigonal-bipyramidal transition state with a small entering-ligand to metal to leavingligand angles was found for the substitution reactions investigated in this paper.

Abstract: Ab initio calculations with an effective core potential have been used to study the mechanism of substitution reactions for square-planar transition-metal complexes. Pseudo-trigonal-bipyramidal transition states with rather small entering-ligand to metal to leaving-ligand angles were found for the substitution reactions investigated in this paper. The stability of the transition state is determined by both σ and π effects of the ligands