Synthesis of two Hofmann type and Hofmann-type-like compounds in crystal form from 4-aminopyridine and their characterizations by various methods

Abstract

This study encompasses the synthesis of two heterometallic tetracyanonickelate(II) complexes based on 4-aminopyridine (4AP) in crystalline form along an investigation of their structural properties. These complexes were characterized by using vibration spectroscopy, elemental analysis, and single crystal X-ray diffraction (SC-XRD) techniques.According to the data obtained using the SC-XRD technique, the heterometallic [Cd(4AP)2Ni(μ4CN)4]n complex has the Triclinic crystal system and the P-1 space group. The other, heterometallic [Ni(4AP)2(H2O)2Ni(μ2CN)2(CN)2]n complex, has Monoclinic crystal system and C2/c space group. The asymmetric unit of heterometallic complex 1 consists of a Ni(II) ion, a Cd(II) ion, two cyanide ligands and a 4AP ligand. Also, the asymmetric unit of complex 2 consists of two Ni(II) ions, a 4AP ligand, two cyanide ligands, and two half coordinated water molecules.The molecular modeling of these complexes was analyzed with the Gaussian 03 program. The chemical properties of the metal complexes were calculated from the resulting HOMO and LUMO values and natural bond orbital (NBO) analysis. The Investigation of the elemental, spectral and SC-XRD data of these complexes reveals that the formulas [Cd(4AP)2Ni(μ4CN)4]n (1) and [Ni(4AP)2(H2O)2Ni(μ2CN)2(CN)2]n (2) fully explain their crystal structure.