DFT OPBE/TZVP Сalculation of Molecular Structures of (5656) Macroheterocyclic Chelates of Double Charged 3d-Element Ions with 1,5,8,11-Tetraazacyclotetradecanetetrathione-2,3,9,10 and Its Dioxa- and Dithia Analogs

Molecular and Electronic Structures of Macrocyclic Compounds Formed at Template Synthesis in the M(II)—Thiocarbohydrazide—Diacetyl Triple Systems: A Quantum-Chemical Analysis by DFT Methods

“…From the optimized structures, the structure with the lowest total energy was chosen for further consideration. In accordance with the theory of the structure of the atoms, Ni(II), Cu(II), and Zn(II) which are the complexes under examination, should correspond to 3d 8 , 3d 9 , and 3d 10 electronic configurations, respectively. In this context, spin multiplicities 1 and 3 in the case of Ni(II) and Zn(II) and spin multiplicities 2 and 4 in the case of Cu(II) are considered for the given central metal ions during the calculation.…”

“…In view of the foregoing, the ML complexes under consideration can be considered practically planar (although, given that they also include, among other things, four methyl groups that are not a priori planar, it should be recognized that none of them). This fact is very interesting; considering that, according to quite numerous data presented in [2][3][4][5][6][7][8][9][10], macrotetracyclic chelate complexes of 3d elements with cyclic ligands containing two five-membered and two six-membered metal chelate rings, contrary to theoretical expectations, are non-coplanar, and in them, as a rule, all these four cycles are non-coplanar. Each of the NiL, CuL, and ZnL complexes under consideration has one second-order axis, a horizontal plane of symmetry, and a center of symmetry, and, consequently, they all have the C 2h symmetry group.…”