New cyano bridged heteropolynuclear Cu(II) and Cd(II)-tetracyanopalladate(II) polymeric complexes with 2-methylimidazole ligand Günes ß Süheyla Kürkçüog ˘lu a,⇑ , Kansu Gör b , Orhan Büyükgüngör c a Eskis ßehir Osmangazi University, Faculty of Arts and Sciences, Department of Physics, TR-26480 Eskis ßehir, Turkey b Eskis ßehir Osmangazi University, The Institute of Science, Department of Physics, TR-26480 Eskis ßehir, Turkey c Ondokuz Mayıs University, Faculty of Arts and Sciences, Department of Physics, TR-55139 Samsun, Turkey highlights Two new bimetallic cyano complexes were synthesized and characterized. In the complex 1, the adjacent 2D layers were connected by the N–HN hydrogen bonds. The crystal structure is formed by infinite 2,2-TT type chains. graphical abstract The experimental study on complex 1 has revealed the importance of the non-covalent N–HN hydro- gen bonds between the N atom of CN group and the hydrogen atom of 2-methylimidazole ligand. article info Article history: Received 22 October 2013 Received in revised form 24 December 2013 Accepted 8 January 2014 Available online 21 January 2014 Keywords: Cyano-bridging complex Tetracyanopalladate(II) complex 2-Methylimidazole complex FT-IR and Raman spectra Thermal analyses Crystal structure abstract New cyano-bridged heteronuclear polymeric complexes, [M(mim) 2 Pd(CN) 4 ] n (M = Cu(II) (1) or Cd(II) (2); mim = 2-methylmidazole), have been synthesized and characterized by elemental, thermal, FT-IR and Raman spectral analyses. The crystal structure of complex 1 has been determined by single crystal X- ray diffraction technique. The crystallographic analysis reveals that it crystallizes in the monoclinic sys- tem, space group P2 1 /c. The Pd(II) atom is coordinated by four cyano ligands, while Cu(II) atom is also sur- rounded by the two mim and two cyano ligands. The structure of 1 is formed by infinite 2,2-TT type chains of the [–Cu(mim) 2 –NC–Pd(CN) 2 –CN–] n composition; these are interlinked by hydrogen bonds (HBs) leading to two-dimensional patterns. FT-IR and Raman spectral data indicate the presence of bridg- ing cyano ligands in the structures of the complexes. Ó 2014 Elsevier B.V. All rights reserved. Introduction Cyano-bridged complexes were among the first coordination compounds ever prepared, studied, described and used [1–4] and they are still popular in coordination and organometallic chemistry at present. The ability of the cyano group to link various central atoms is used in organometallic and coordination chemistry for the construction of various supercomplexes or molecular assem- blies [5–7] and in the field of supramolecular chemistry for build- ing various 1D, 2D or 3D structures [8–12]. The cyano-bridged complexes exhibiting polymeric structures can mimic the naturally 1386-1425/$ - see front matter Ó 2014 Elsevier B.V. All rights reserved. http://dx.doi.org/10.1016/j.saa.2014.01.049 ⇑ Corresponding author. Tel.: +90 222 2393750; fax: +90 222 2393578. E-mail address: gkurkcuo@ogu.edu.tr (G.S. Kürkçüog ˘lu). Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy 124 (2014) 588–594 Contents lists available at ScienceDirect Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy journal homepage: www.elsevier.com/locate/saa