The hybrid density functional theory B3LYP method with the 6-31G(d) basis set and the Gaussian 98 program has been used for calculating the geometric parameters of the Mn(II), Co(II), Ni(II), and Cu(II) complexes with NNSS-donor macrocyclic ligands forming in the course of template processes in the M(II)-dithiooxamide-formaldehyde systems. The bond lengths and bond angles in the complexes with the MN₂S₂ metal chelate core are reported. For all M(II) ions, the extra six-membered chelate ring that form as a result of template assembly is rotated through a rather large angle with respect to two five-membered rings and the ring itself is not planar.

The geometric parameters of (5656)macrotetracyclic complexes of Mn(II), Fe(II), Co(II), Ni(II), Cu(II), and Zn(II) with the NNNN-coordination of donor sites of the chelant formed by the template reactions in the M(II)-ethanedithioamide-formaldehyde-ammonia systems have been calculated by the OPBE/TZVP hybrid density functional theory (DFT) method with the use of the Gaussian09 program package. In all complexes, five-membered chelate rings (almost identical to each other in each complex) are nonplanar. For all M(II) ions under consideration, two additional six-membered nonplanar chelate rings formed as a result of template “cross-link” are turned at considerable angles with respect to the five-membered rings. The six-membered rings are located on different sides of the NNNN plane of the nitrogen donor atoms.

The thermodynamic and geometric parameters of M(II) macrotetracyclic chelates (M = Mn, Fe, Co, Ni, Cu, and Zn) with the (NNNN) coordination of the donor ligand sites, formed by the complexation reactions of corresponding M(II) compounds, ethanedithioamide H₂N-C(=S)-C(=S)-NH₂, and acetone H₃C-C(=O)-CH₃ in gelatin-immobilized matrix implants have been calculated by the OPBE/TZVP density functional theory method with the use of the Gaussian 09 program package. The bond lengths and bond and torsion angles in these complexes have been reported. It has been shown that despite the fact that the MN₄ chelate core in them is almost planar, the five- and six-membered chelate rings are pronouncedly non-coplanar. In the Mn(II), Fe(II), Co(II), and Ni(II) complexes, these chelate rings are pairwise identical, whereas in the Cu(II) and Zn(II) complexes, they are noticeably different.

The thermodynamic and geometric parameters of the macrocyclic chelates of Mn(II), Fe(II), Co(II), Ni(II), Cu(II), and Zn(II) with the (NNNN) coordination of the ligand donor centers formed upon complexation between the above metal ions, hydrazinomethanethiohydrazide (H₂N-HN-C(=S)-NH-NH₂), and 2,3-butanedione (H₃C-C(=O)-C(=O)-CH₃) in gelatin-immobilized matrix implants were calculated by the B3LYP 6–31G(d) density functional theory method with the use of the Gaussian 09 program package. The bond lengths, valence angles, and torsion angles were reported, and it was noted that the complexes of Fe(II), Co(II), Ni(II), and Cu(II) are almost planar, whereas the complexes of Mn(II) and Zn(II) have a quasi-pyramidal structure of the chelate unit. The additional six-membered metallocycles resulting from template cross-linking, as well as five-membered rings, are almost planar.

The thermodynamic and geometric parameters of isomeric macrotricyclic Mn(II), Fe(II), Co(II), Ni(II), Cu(II), and Zn(II) complexes that can, in principle, be the products of the reaction of corresponding hexacyanoferrates(II) with thiocarbamoylmethanamide H₂N-C(=S)-C(=O)-NH₂ and formaldehyde in gelatin-immobilized matrix implants have been calculated by the hybrid B3LYP density functional theory method with the use of the 6–31G(d) basis set and the Gaussian 98 program package. For any of the M(II) ions under consideration, the most stable complexes have the MN₄ metal chelate cores. The bond lengths and bond angles in these complexes have been reported, and it has been stated that the five-membered chelate rings in the complexes are not strictly planar. The additional six-membered chelate ring resulting from template cross-linking is also nonplanar and, in some cases, is turned at a rather large angle to the five-membered rings.