RAMAN-SPECTRA OF BETA-DIKETONATES OF GROUP-III AND GROUP-VIII METALS

The results of a Raman-spectroscopic investigation of beta-diketonates of group III and group VIII metals with the general formula M(n)(R-CO-CH-CO-R)n, where M(n) = Pd(II), Pt(II), Co(III), Rh(III), Ir(III), Al(III), Ga(III), and In(III), and R = CH3, C(CH3)3, CF3, and C6H5, have been presented. It has been concluded on the basis of the significant difference in the behavior of the frequencies of the upsilon(s)(MO) and upsilon(s)(CO) vibrations in the compounds under consideration (with Pd(II), Pt(II), Co(III), Rh(III), and Ir(III) as the central ion, on the one hand, and with Al(III), Ga(III), and In(III) as the central ion, on the other hand) that the d --> pi* interaction plays an important role in the coordinate bonding in the complexes indicated, in agreement with the data from the electronic absorption spectra in the UV and visible regions, as well as with the literature data from x-ray diffraction analysis and C-13 NMR.