DFT quantum-chemical calculations of molecular structures for template heteroligand (5757)macrocyclic M(II) chelates of 3d elements with a 16-membered macrocyclic ligand and Br– ions

Abstract

The geometric parameters of Mn(II), Fe(II), Co(II), Ni(II), Cu(II), and Zn(II) (5757)macrocyclic complexes with the NSSN-coordination of the donor sites of the chelant, which can be generated in template processes in M(II)–N-methylthiocarbohydrazide–hexanedione-2,5 systems and in the subsequent reaction of the newly formed metal chelate with 1,2-di(bromomethyl)benzene, have been calculated by the OPBE/TZVP functional density theory (DFT) hybrid method using the Gaussian09 program package. The 5-membered chelate ring is strictly planar in none of the complexes,. In all complexes (except for the Co(II) complex), 5-membered chelate rings are identical to each other. Both 7-membered chelate rings generated by the template links have a pronounced non-coplanarity. The bond angles between M–Br bonds are not 180° in any one of the complexes studied, although approaching this value.