Specifics of molecular structures of (565)macrotricyclic 3d-Metal chelates in the ternary systems M(II)-hydrazinecarbothioamide-2,4-Pentanedione according to DFT calculations

Abstract

The geometric parameters of the molecular structures and thermodynamic parameters of formation of macrotricyclic M(II) complexes (M = Mn, Fe, Co, Ni, Cu, and Zn) with the MN2S2 coordination core formed by the reactions of corresponding hexacyanoferrates(II) with hydrazinecarbothioamide H2N-HN-C(=S)-NH2 and 2,4-pentanedione H3C-C(=O)-CH2-C(=O)-CH3 in gelatin-immobilized matrix implants have been calculated by the B3LYP hybrid density functional theory method with the use of the 6-31G(d) basis set and the Gaussian 09 program package. The bond lengths and bond and torsion angles in these chelates have been reported. It has been shown that the Fe(II) and Ni(II) complexes are strictly planar, whereas the Mn(II), Co(II), and Cu(II) complexes are quasi-planar with a rather small deviation of the MN2S2 chelate core from coplanarity, and only the Zn(II) complex is pseudotetrahedral. The additional sixmembered chelate rings resulting from the above processes are almost planar in all chelates.