Spectrochemical properties of noncubic transition metal complexes in solution. XI. Angular overlap studies of bis(oxalato)- and bis(malonato)diaquachromate(III) complexes in aqueous solution

Mixed ligands chromium(III) complexes with monodentate (water) and bidentat e ligands: oxalic acid deprotonated (o (-), oxalate ion) or malonic acid (m al (-), malonate ion), have been synthesized, investigated and characterize d structurally and spectroscopically. Their geometrical isomers: cis- and t rans-, have been studied spectrophotometrically in aqueous solution. The "p oor" experimental contours were resolved into the component bands by Gaussi an analysis. The spectra were interpreted using D-2h and C-2v symmetry for trans- and cis- isomer, respectively. The resolved spectra have been treate d using an angular overlap model (AOM). The effect of sigma- and pi-bonding of the bidentate ligands upon the chromium(III) ion in aqueous solution wa s described and discussed.