Experimental and theoretical Raman study of the binuclear copper(II) imidazole saccharinato complex

The 1800-180 cm(-1) region of the solid-state Raman spectrum of the binucle ar imidazole adduct of copper(II) saccharinate, featuring the shortest C-O bond in all structurally characterized saccharinates, was studied together with those of saccharin and other saccharinato compounds. The appearance of the spectral regions of the characteristic CO, SO2 and metal-ligand stretc hing vibrations was correlated with the corresponding structural data. The Raman spectrum of the free saccharinato ion was computed at the HF/6-31++G( d,p) level and used to assign the internal vibrational modes of the sacchar inato ligands, It was concluded that, primarily owing to the coupling of th e nu(CO) mode, two-dimensional d(C-O) vs <(nu)over bar>[nu(CO)] correlation s in the metal saccharinates in the solid state are qualitative and more pr ecise analysis should include the effects of other structural factors (e,g, ligation or intermolecular interactions) on the nu(CO) wavenumber. Copyrig ht (C) 2000 John Wiley & Sons, Ltd.