Abstract
A zinc(II)-cyanide complex of cis-1,2-diaminocyclohexane (Dach) containing two dinuclear units, [Zn-2(Dach)(4)(CN)][Zn-2(CN)(7)]center dot 2CH(3)OH (1) was prepared and characterized by IR and NMR spectroscopy as well as by single crystal X-ray crystallography. Complex 1 is composed of two dinuclear ionic units, cationic [Zn-2(Dach)(4)(CN)](3+) and anionic [Zn-2(CN)(7)](3-) and two non-coordinating molecules of methanol. The Zn atoms in [Zn-2(Dach)(4)(CN)](3+) cation adopt a square-pyramidal environment with CN ligand occupying the apical position, while the Zn atoms in [Zn-2(CN)(7)](3-) anion exhibit a tetrahedral geometry. The dinuclear units are associated to each other through hydrogen bonding interactions to form a three dimensional network in the solid state. The presence of, a band around 2200 cm(-1) in IR spectrum and a resonance at 140 ppm in C-13 NMR indicated the presence of cyanide in the complex. The structures of 1 and two of its analogues, [Zn(Dach)(CN)(2)](4) (2) and {[Zn(Dach)(2)][Zn(CN)(4)])(2) (3) were predicted using theoretical (DFT) method. The DFT calculated values of the Gibbs free energies of the model complexes reveal that 1 is more stable than the analogous predicted complexes, 2 and 3 by 5.16 and 3.47 kcal mol(-1), respectively. (C) 2018 Elsevier B.V. All rights reserved.