Synthesis, Characterization, Spectral, Magnetic, XRD and ESR Studies on Some Novel Trinuclear Copper(II) Tetrathiocyanatodiargentate(I) Complexes with Acyl Hydrazine and Hydrazone Bases

Abstract

Copper(II) complexes of the type CuAg₂(SCN)₄˙L (where L = benzoylhydrazine (BH), p-hydroxybenzoylhydrazine (PHBH), salicyloylhydrazine (SH), isonicotinoylhydrazine (INH), anthraniloylhydrazine (AH) and their isopropanone derivatives viz., isopropanone benzoylhydrazone (IBH), -salicyloylhydrazone (ISH), -anthraniloylhydrazone (IAH), and -isonicotinoylhydrazone (IINH) have been synthesized and characterized with the help of elemental analyses, electronic and IR spectra and magnetic moment data. Electronic spectral bands and μ_eff values suggest a distorted octahedral environment around copper(II). SCN groups act as bridge between two metal centres while all the ligands are bi-coordinately bonded through >C=O and -NH₂ or >C=N-groups, except in CuAg₂ (SCN)₄˙L (L = INH and IINH) where the ligands are coordinated through -NH₂/-N=C< and pyridyl ring nitrogens. Powder ESR data suggest an isotropic nature of all the complexes except for CuAg₂ (SCN)₄.SH where an axial nature of copper(II) is observed. Presence of half field signal in CuAg₂ (SCN)₄.PHBH complex suggests its dimeric nature. Powder X-ray diffraction studies for CuAg₂(SCN)₄ and CuAg₂ (SCN)₄. IBH suggest the presence of orthorhombic and tetragonal crystal lattice respectively.