Three new complexes [M(deten)(2)Ni(mu-CN)(2)(CN)(2)] (n) (M = Ni, Cu and Cd, deten = N,N-diethylethylenediamine) have been synthesized and characterized by chemical, thermal analysis, FT-IR and Raman spectroscopies. The crystal structure of the Cd complex has been determined by X-ray single crystal diffraction. Structural study reveals that the Ni2+ and Cd2+ ions are located on inversion centers, and adopt slightly distorted square-planar and octahedral geometries, respectively. In the crystal structure, the intermolecular N-Ha <-N hydrogen bonds link the polymeric chains into a two dimensional network. Vibrational spectral data indicate the presence of two nu(Ca parts per thousand N) for complexes can be assigned to the terminal and bridging cyanides. The decomposition reaction take places in the temperature range 30-1000 A degrees C in the static air atmosphere.