New solid state Ni(II)-famotidine square-planar complex: powder diffraction and spectroscopic studies

Recent potentiometric studies have claimed that Ni(II) forms three pH-dependent complexes with famotidine. We isolated two of them from the solution; namely the paramagnetic complex NiL with octahedral geometry and the diamagnetic complex NiH-L-2 with square-planar geometry, The latter compound constitutes the subject of this work. The crystal structure of nickel (II) famotidine complex NiC8N7O2S3H13 discussed here, determined with the powder diffraction method, has shown that it belongs to a Pben space group (60) with a, b, c = 24.328(4), 14.747(2), 7.786(1), V = 2793.6(5) Angstrom 3. R-F and R-wp are 16.1% and 15.5%, respectively. Additionally, the UV-VIS, FT-FIR and Raman spectroscopic methods were employed to discuss and support the structure of the NiH-L-2 complex suggested by X-ray data. The structure presented in this work is the second example of the complex of a famotidine ligand with a transition metal ion in the solid state. The other one, reported from a single crystal X-ray structure of famotidine complex with Cu(II), is quite different. (C) 2004 Elsevier Inc. All rights reserved.