Quantum chemical calculation of the molecular structures of (666)macrotricyclic chelates of 3D elements in the M(II)-propanedithioamide-formaldehyde systems by the density functional theory method

The nonhybrid OPBE/TZVP density functional theory (DFT) method and the Gaussian09 program package were used to calculate the thermodynamic and geometric parameters of asymmetric macrocyclic M(II) complexes with three six-membered metal rings and (NNNN)-coordination of the donor sites of the ligand. The complexes are formed upon self-assembly (template synthesis) of hexacyanoferrates(II) of the corresponding M(II), propanedithioamide H₂N-C(=S)-CH₂-C(=S)-NH₂, and formaldehyde H₂C(=O) in gelatin-immobilized matrix implants. Note that complexes of this type are formed only for M = Ni, Cu, and Zn, while for M = Mn, Co, and Fe, these compounds are unstable. Bond lengths and bond and torsion angles are presented. In each of these complexes, both the MN₄ chelate units and the N₄ units and all sixmembered metal rings were found to be non-coplanar.