Several coordination compounds (1:1) formed between alkaline earth metal cations [Mg(II), Ca(II) and Ba(II)] and transition metal ions [Co(II), Ni(II) and Zn(II)] with oflocaxin were synthesized. The compounds have been characterized using elemental analysis, Fourier transform infrared (FT-IR) spectroscopy and H-1 NMR spectra. The solid state samples of all complexes have been measured within the range 4000-400 cm(-1). Based on normal mode calculations for complexes, the assignments of bands observed in FT-IR spectra of studied compounds have been done. Some significant differences in vibrational structure have been observed and discussed. The frequencies and intensities of some bands of the ofloxacin depend systematically on the second ionization potential of the metals. (C) 2003 Elsevier B.V. All rights reserved.