Models of molecular structures of macrocyclic metal chelates in the ternary 4d M(II) ion–ethanedithioamide–ethanedial systems according to quantum-chemical DFT calculations

Abstract

The thermodynamic and geometric parameters of the molecular structures of macrotricyclic Tc(II), Ru(II), Rh(II), Pd(II), Ag(II), and Cd(II) complexes with the (NSSN)-coordination of the ligand donor sites formed by complexation of the corresponding M(II) ions with ethanedithioamide H₂N–C(=S)–C(=S)–NH₂ and ethanedial HC(=O)–CH(=O) have been calculated by the OPBE/TZVPQZP hybrid density functional theory method with the use of the Gaussian09 program package. The bond lengths and bond angles in these complexes have been reported, and it has been stated that the Rh(II) and Ag(II) complexes are nearly planar, the Tc(II), Pd(II), and Cd(II) complexes are slightly nonplanar, while the Ru(II) complex exhibits a rather considerable deviation from coplanarity. The additional five-membered chelate ring resulting from template cross-linking is either strictly planar (in the Tc(II), Rh(II), Pd(II), and Ag(II) complexes) or nearly planar (in the Ru(II) and Cd(II) complexes).