Abstract
Zinc(II) complexes of diamines, cis-1,2-diaminocyclohexane (Dach) and N,N,N,N-tetramethylethylenediamine (Tmen), [Zn(Dach)(NCS)(2)](1) and [Zn(Tmen)(NCS)(2)] (2) have been prepared and characterized by elemental analysis, IR, H-1 & C-13 NMR spectroscopy. The crystal structure of [Zn(Dach)(NCS)(2)] (1) was determined by X-ray crystallography. In 1, the Zn(II) atom is bound to one 1,2-diaminocyclohexane molecule and to two terminal thiocyanate ions via the nitrogen atoms adopting a slightly distorted tetrahedral geometry. In the crystal structure, molecules are linked through intermolecular N-H center dot center dot center dot S hydrogen bonds, forming chains running along the a axis. The structures of I and 2 as well as of [Zn(En)(NCS)(2)] (3) (En = 1,2-diaminoethane) were predicted using theoretical (DFT) method. The interaction energies (Delta E) for NCS anions obtained by B3LYP-D3 method are about -140 kcal mol(-1), while the calculated Delta E values for neutral organic ligands are about twice smaller. The atomic charges and second-order interaction energies between orbitals were calculated with natural bond orbital (NBO) analysis. (C) 2016 Elsevier B.V. All rights reserved.