Hetero-Metallic Coordination Polymers: Syntheses, Vibrational Spectra, Thermal Analyses and Crystal Structures of trans- [M(N-Meim) 2 Ni(l–CN) 4 ] n (M=Cu(II), Zn(II) and Cd(II)) Gu ¨nes ¸ Su ¨heyla Ku ¨rkc ¸u ¨og ˘lu Æ Okan Zafer Yes ¸ilel Æ _ Ilkan Kavlak Æ Orhan Bu ¨yu ¨kgu ¨ngo ¨r Received: 3 June 2009 / Accepted: 5 July 2009 / Published online: 24 July 2009 Ó Springer Science+Business Media, LLC 2009 Abstract Three cyano bridged hetero-metallic complexes of general formula, trans-[M(N-Meim) 2 Ni(l-CN) 4 ] n (N-Meim= N-methylimidazole and M=Cu(II), Zn(II) or Cd(II)) have been synthesized and characterized by vibrational (FT-IR and Raman) spectroscopy, single crystal X-ray diffraction, thermal analyses and elemental analyses. The crystallographic analyses reveal that the complexes, [Cu(N-Meim) 2 Ni(l-CN) 4 ] n (1), [Zn(N-Meim) 2- Ni(l-CN) 4 ] n (2) and [Cd(N-Meim) 2 Ni(l-CN) 4 ] n (3), have poly- meric 2D networks. In the complexes, four cyanide groups of [Ni(CN) 4 ] 2- coordinated to the adjacent M(II) ions and distorted octahedral geometries of complexes are completed by two nitrogen atoms of trans N-Meim ligands. Vibration assignments are given for all the observed bands and the spectral features also supported to the crystal structures of polynuclear complexes. Keywords Hetero-metallic complexes Á Cyano-bridged complexes Á Tetracyanonickelate(II) complexes Á N-Methylimidazole complexes 1 Introduction Cyano complexes were among the first coordination com- pounds ever prepared, studied, described and used [1, 2] and they are still under investigation in coordination and organometallic chemistry at present [3]. In particular, the Hofmann-type compounds [ML 2 M 0 (CN) 4 ] n , which were first prepared by Hofmann in 1897 [2] and extensively studied by Iwamoto and others. They show 2D structures with variety of small molecules intercalated between the layers [4, 5]. Most of these compounds contain ammonia or amines coordinated to the octahedral metal center to complete their coordination. These compounds are inter- esting as ion exchangers, molecular sieves or materials for storing gases [6]. Square planar [M(CN) 4 ] 2- (M=Ni, Pd, Pt) have been extensively used as building blocks for the synthesis of extended cyano-bridged metal complexes [7–14]. The Hofmann type host structure [M(NH 3 ) 2 Ni(CN) 4 ] n is built up of the linkage of the square-planar tetracyano- nickelate(II) moieties and the [M(NH 3 ) 2 ] 2? groups, with the NH 3 molecules protruding above and below the [M-Ni (CN) 4 ] n layers [15, 16]. Based on this structure several metal(II) tetracyanonickelate complexes related to Hof- mann-type host have been developed by replacing the ammonia molecules by other N-donor ligands [17–19]. In previous studies, the complexes of imidazole and its methyl derivatives with the metal(II) ion were described in several papers [20–30]. However, to the best our knowledge, neither crystallographic, nor spectroscopic data have been so far would explicity tell the structural analyses of the N-Meim complexes of tetracyanonickelate(II) ions. We have recently reported the {[Cu(4(5)-Meim) 4 ][Ni(CN) 4 ]Á H 2 O} n tetracyanonickelate(II) complex with a 4(5)-meth- ylimidazole [31]. In this study, we have now prepared the cyano bridged heteronuclear polymeric complexes of the G. S. Ku ¨rkc ¸u ¨og ˘lu (&) Á _ I. Kavlak Faculty of Arts and Sciences, Department of Physics, Eskis ¸ehir Osmangazi University, TR-26480 Eskis ¸ehir, Turkey e-mail: gkurkcuo@ogu.edu.tr O. Z. Yes ¸ilel Faculty of Arts and Sciences, Department of Chemistry, Eskis ¸ehir Osmangazi University, TR-26480 Eskis ¸ehir, Turkey O. Bu ¨yu ¨kgu ¨ngo ¨r Faculty of Arts and Sciences, Department of Physics, Ondokuz Mayıs University, TR-55139 Samsun, Turkey 123 J Inorg Organomet Polym (2009) 19:539–548 DOI 10.1007/s10904-009-9295-3