Vibrational and thermal studies of metal(II) [Ni(II), Zn(II) and Cd(II)] iodide m-methylaniline complexes A. Altun * , K. Go ¨lcu ¨k, M. Kumru Department of Physics, Faculty of Arts and Sciences, Fatih University, 34900 B. C ¸ekmece, Istanbul, Turkey Received 15 August 2002; received in revised form 26 November 2002; accepted 5 December 2002 Abstract The complexes of the M(m-methylaniline) n I 2 (n ¼ 2, M ¼ Zn and Cd; n ¼ 4, M ¼ Ni) form were prepared and characterized by their FT-infrared (IR) spectra, FT-Raman spectra, thermal analyses, elemental analyses and UV-vis electron absorption spectra. The observed IR and Raman bands of the complexes have been assigned. Coordination effects on the vibrational spectra of m-methylaniline have been investigated. Thermogravimetric (TG) behaviors of the complexes have been discussed. Energy minimization studies on the complexes having the same stoichiometry show that the Zn(II) complex is more stable than the Cd(II) complex and the metal–ligand bond strength of the Zn(II) complex is greater than that of the Cd(II) complex, which are in agreement with the spectroscopic and thermal study results. # 2003 Elsevier Science B.V. All rights reserved. Keywords: m-methylaniline complexes; Infrared (IR) and Raman spectra; Thermal analysis 1. Introduction Although thermal and infrared (IR) spectral studies of most of the metal(II) halide complexes of aniline and its derivatives have been reported [1–9], the information available in the literature on metal(II) iodide m-methylaniline (mMA) complexes is scarce. In the previous study, we established the force field of mMA based on ab initio and density functional theory (DFT) calculations [10]. The influence of the transition metal on the mMA vibrational wavenumbers is another subject of interest. In this respect, we report FT-IR and FT-Raman spectroscopic study of Zn(mMA) 2 I 2 , Cd(mMA) 2 I 2 and Ni(mMA) 4 I 2 complexes. We have also investigated the thermal behaviors of these complexes in this study. The information available for these complexes in the literature is only on some of the IR frequencies [4,8]. Neither complete IR studies nor any measurements for Raman spectra and thermal analysis have been performed for these complexes so far. 2. Experimental All starting materials (NiI 2 , ZnI 2 , CdI 2 and m- methylaniline) were reagent grade (Fluka–Aldrich) and were used without further purification. The com- plexes of the powder form were prepared by addition of the appropriate quantity of mMA to the solution of the metal iodide in ethanol. The reaction mixture was stirred magnetically for each complex about 3 h. While Zn(II) and Cd(II) complexes were formed at room temperature, Ni(II) complex was obtained after Vibrational Spectroscopy 31 (2003) 215–225 * Corresponding author. Tel.: þ90-212-889-08-10x2085; fax: þ90-212-889-11-42. E-mail address: aaltun@fatih.edu.tr (A. Altun). 0924-2031/03/$ – see front matter # 2003 Elsevier Science B.V. All rights reserved. doi:10.1016/S0924-2031(03)00017-1