Synthesis, crystal structure and thermal stability of bis(1,10-phenanthroline) cobalt(II) cyanide ethanol solvate dihydrate

Abstract

The compound [Co(phen)2(CN)2]·EtOH·2H2O was obtained by reaction of Co(CN)2 and 1,10-phenanthroline (phen) in 95% EtOH solution and characterized using IR and UV spectroscopy, thermogravimetric-differential thermal analysis (TG-DTA) and X-ray crystallography. The deep-brown crystal is triclinic, space group P , with lattice parameters a = 10.356(2), b = 10.505(2), c = 12.148(2) Å, α = 79.19(3), β = 79.68(3), γ = 86.71(3)° and Z = 2. The compound contains a six-coordinate cobalt atom chelated by two phen ligands and two cyanide anions in a cis arrangement. One ethanol solvate molecule and two water molecules complete the crystal structure. In the solid state, the title compound forms a network structure through hydrogen bonds. Intermolecular hydrogen bonds connect the [Co(phen)2(CN)2], ethanol and H2O moieties. TG data indicate that thermal decomposition of the compound takes place in four steps, and the final product of thermal decomposition is CoC2. Elemental analysis, IR and UV spectra are in agreement with the structural data.