Synthesis, Crystal Structure and Physicochemical Characterization of Two Ni(II)-Famotidine Metal Complexes

Abstract

The coordination ability of the antisecretor agent Famotidine (FMT) was explored using Ni(II) as central ion. [NiFMTH-2] and [Ni(FMT)2]Cl2 were obtained by the solvent evaporation method from the corresponding starting solutions at pH 8 and 4, respectively; the crystal structure was elucidated by single crystal X-ray difraction in both cases.[NiFMTH-2] resulted in a distorted square-planar geometry, where FMT acts as a tetradentate dianionic ligand through nitrogen atoms belonging to the guanidine group, the thiazolic ring and the side chain, and a sulfur atom from the thioether moiety. [Ni(FMT)2]Cl2 exhibits an octahedral environment composed by two FMT molecules that coordinate by nitrogen atoms deriving from guanidine and thiazole ring moieties, and the thioether sulfur atom. The physicochemical characterization was completed by means of FTIR and UV–Vis spectroscopies, and thermal analysis. Solubility measurements were performed and the results could be satisfactorily correlated with the solvation Gibbs free energy (ΔGsolv) values in aqueous solution obtained using the SDM model by DFT calculations.