Raman Spectra in the Skeletal Vibration Region of [Co(gly)x(ox)y(en)z](3−x−2y)+ Complexes (x+y+z=3)

Abstract

Abstract The Raman spectra were measured for the complete series of cobalt(III) complexes, [Co(gly)x(ox)y-(en)z](3−x−2y)+, where gly, ox, and en denote glycinate, oxalate, and ethylenediamine, respectively, and x+y+z is equal to 3, in aqueous solution in the skeletal vibration region to deduce their structure-spectra relation. The spectra could be classified into four categories: polarized bands in the 610–520 cm−1 region due to a totally symmetric stretching vibration mode, depolarized bands in the 520–400 cm−1 region due to Co–O and Co–N stretching vibration modes, depolarized bands in the 400–300 cm−1 region due to the metal-ligand skeletal bending deformation mode, and polarized bands in the 300–200 cm−1 region due to the chelate ring deformation mode. The depolarized bands due to the stretching vibration mode could be used for the differentiation of C2-cis and C1-cis isomers of [Co(N)4(O)2] and [Co(N)2(O)4] type complexes.