D. V. Chachkov

Geometric parameters and energies of molecular structures of macrocyclic metal chelates in the ternary 3d M(II) ion-ethanedithioamide-ethanedial systems according to quantum-chemical DFT B3LYP calculations

The thermodynamic and geometric parameters of isomeric macrotricyclic Mn(II), Fe(II), Co(II), Ni(II), Cu(II), and Zn(II) complexes with the (NSSN) coordination of the ligand donor centers formed in the reaction of corresponding hexacyanoferrates(II) with ethanedithioamide H2N-C(=S)-C(=S)-NH2 and ethanedial HC(=O)-CH(=O) 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 03 program package. The bond lengths and bond and torsion angles in these complexes have been reported, and it has been stated that the Mn(II), Co(II), and Cu(II) complexes are nearly planar, the Fe(II) and Ni(II) complexes are slightly nonplanar, while the Zn(II) complex exhibits a rather considerable deviation from coplanarity. The additional five-membered chelate ring resulting from template cross-linking is almost planar in all cases.

Molecular structure and thermodynamic parameters of (5656)macrotetracyclic chelates in the 3d-element(ii) ion-hydrazinomethanethiohydrazide-2,3-butanedione ternary system according to density functional quantum-chemical calculations

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.

Structure of (5656)macrotetracyclic chelates in the ternary systems M(II)-ethanedithioamide-acetone (M = Mn, Fe, Co, Ni, Cu, Zn) according to DFT calculations

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.

Quantum-chemical calculation of molecular structures of (5656)macrotetracyclic 3d-metal complexes “self-assembled” in quaternary systems M(II) ion-ethanedithioamide-formaldehyde-ammonia by the density functional theory method

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.

On the possibility of template synthesis in the ternary system of vanadium(IV)-dithiooxamide-formaldehyde

With application of hybride method of density functional B3LYP with the 6–31G(d) basis set we calculated geometric parameters of macrocyclic complexes formed at the template reactions in the system V(IV)-dithiooxamide-formaldehyde of dioxovanadium(IV). The complexes are formed by tetradentate chelate ligands by means of (NNSS)- and (NNNN)-coordination of donor centers. Atomic coordinates and bond lengths of the formed complexes are listed. The values of enthalpy and Gibbs energy of the formation of the complexes are calculated and it is resumed that the template synthesis in such system can be realized at the complex formation in gelatin-immobilized matrix only.

Molecular structures of “template” (5555)macrotetracyclic chelates of 3d M(II) ions with 1,4,7,10-tetraaza-1,3,8-dodecatriene-5,6,11,12-tetrathione according to DFT quantum-chemical calculations

The geometric parameters of the molecular structures of M(II) (5555)macrotetracyclic complexes with a tetradentate (NNNN) macrocyclic ligand, formed by template reactions in the systems M(II)-ethanedithioamide-ethanedial-1,2-ethenediol systems, as well as of the molecular structure of the template ligand forming the coordination sphere of these complexes, have been calculated by the OPBE/TZVP density functional theory method. The bond lengths and bond and torsion angles in the complexes, as well as the standard enthalpies, entropies, and Gibbs energies for each of them, are reported.

Quantum-chemical calculation of steric structure of the complexes formed at template synthesis in three-component systems of Co(II) [Ni(II), Cu(II)] ion-bithiooxamide-acetone

By means of hybrid method of the density functional B3LYP with 6-31G(d) basis set we carried out calculation of geometric parameters of Co(II), Co(III), Ni(II) and Cu(II) complexes with macrocyclic ligand formed at the template processes in the systems M(II)-dithiooxamide-acetone with NNSS-coordination of donor centers. Atomic coordinates, bond lengths, bond angles and dihedral angles in the complexes with metallochelate node MN2S2 are listed. In the cases of Ni(II) and Cu(II) this chelate node is practically planar while in the case of Co(II) is tetrahedral. An additional six-membered metallocycle formed as a result of template “stitching” is screwed and turned by enough significant angle relative to five-membered rings.

Theoretical Study of the Mechanism of the Nitro-Nitrite Rearrangement and Its Role in Gas-Phase Monomolecular Decomposition of C-Nitro Compounds

Semiempirical, ab initio, and density functional theory calculations were used to study the primary act of gas-phase monomolecular decomposition of certain C-nitro compounds and their radical cations, associated with the nitro-nitrile rearrangement. It was shown that the reaction fails to occur with all neutral molecules of aliphatic nitro compounds (except for fluoronitromethane and fluoronitroethene) and has a much lower barrier with the corresponding radical cations. An important role of the nitro-nitrile rearrangement in gas-phase decomposition of aromatic nitro compounds was demonstrated.

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

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.

Molecular structures of (555)macrotricyclic chelates appearing in 3d-element(ii) ion-hydrazinomethanethioamide-ethanedial systems according to density functional theory calculations

Thermodynamic and geometric parameters have been calculated using the hybrid density functional theory method B3LYP with the 6-31G(d) basis set and the Gaussian03 program for the macrotricyclic complexes of Mn(II), Fe(II), Co(II), Ni(II), Cu(II), and Zn(II) with an (NSSN)-coordinated ligand that can result from the complexation of metal hexacyanoferrates(II) with hydrazinomethanethioamide H2N-HN-C(=S)-NH2 and ethanedial HC(=O)-CH(=O) in gelatin-immobilized matrix implants. Bond lengths and valence and torsion angles in these complexes are reported. The Ni(II) and Cu(II) complexes are practically planar. The Mn(II), Fe(II), and Co(II) complexes are characterized by a small deviation from coplanarity, and the Zn(II) complex is noticeably noncoplanar. The additional five-membered metallacycle resulting from template “joining” is nearly planar in all complexes.