The synthesis of two new Hofmann-type M(3-aminopyridine)2Ni(CN)4 [M = Zn(II) and Cd(II)] complexes and the characterization of their crystal structure by various spectroscopic methods

Abstract

The aim of this work is to obtain new examples of Hofmann-type complexes in single crystal form. Two novel Hofmann-type Zn(3-aminopyridine)2Ni(CN)4 (1) and Cd(3-aminopyridine)2Ni(CN)4 (2) complexes in a single crystal form have been synthesized and characterized by elemental, thermal and vibrational (FT-IR and FT-Raman) analysis. The general information about the structural properties of these Hofmann-type complexes 1 and 2 was acquired from the FT-IR and FT-Raman spectra by considering changes at characteristic peaks of the cyano group and 3-aminopyridine ligand molecule. The thermal behaviors of these Hofmann-type complexes 1 and 2 have also been investigated in the range of (50–600) 0C using the TG and DTG methods. Also, the magnetic susceptibility measurements of these Hofmann-type complexes 1 and 2 were made at the room temperature using the Gouy-balance. The properties of the structure of the Hofmann-type complexes 1 and 2 have been determined by the single crystal diffraction technique. The asymmetric units of the Hofmann-type complexes 1 and 2 contain one M(II) ion [M = Zn(II) in the crystal 1 and Cd(II) in the crystal 2], one Ni(II) ion, one 3-aminopyridine ligand, and one cyanide ligand. The most important feature of the Hofmann-type complexes 1 and 2 is the presence of obvious intermolecular CH···Ni interactions between Ni(II) ion and H atom of the 3-aminopyridine ligand molecule. All spectral and thermal data also support the crystal structures of the Hofmann-type complexes 1 and 2. These newly obtained Hofmann-type complexes 1 and 2 can be used to imprison certain molecules suitable for the gaps in their structure or to separate certain sized molecules one from another as molecular sieves.