Complexes 1 -3 were characterized fully by solid-state IR spectroscopy at room temperature (Figure ). The IR spectra display the characteristic C=O stretching vibration of the coordinated bik-Et and bik-Me ligands at around 1644 cm -1 . The (CO) of the coordinated dbm and acac ligands were observed at around 1595 and 1587 cm -1 respectively. In addition, IR spectra of all complexes show typical absorptions of the coordinated dbm, acac, bik-Et and bik-Me ligands which are slightly shifted in comparison to the free ligands.