The VCD spectra of a series of tris(acetylacetonato)metal(III) ([M(acac)(3)] with M = Co, Cr, Ru, and Rh) have revealed a new aspect concerning the effects of a central metal ion on the vibrational energy levels split by the inter-ligand interactions. Our present view is that the correlated vibrational motions of vicinal ligands are affected by the d-electron configuration of a central metal ion.