SPECTROSCOPICAL PROPERTIES OF DI(PHTHALOCYANINATO)METALATES(III) OF THE RARE-EARTH ELEMENTS .1. ELECTRONIC ABSORPTION AND VIBRATIONAL-SPECTRA

Di(phthalocyaninato)metalates(III) of the rare earth elements were prepared by the reaction of partially dehydrated lanthanide acetate with molten phthalodinitrile in the presence of potassium methylate and isolated as complex salts with different tetraalkylammonium cations, especially tetra(n-butyl)- and tri(n-dodecyl)n-octylammonium and di((triphenyl)phosphine)iminium (abbrev.: (nBu4N), TDOA, PNP). Besides the typical strong pi-pi* transitions in the B, Q, N regions of the Pc2- ligands low intensity bands at ca. 10, 11 and 19 kK are observed in the UV-Vis-NIR spectra and assigned to singulet-triplet transitions. In going from La to Lu the B band splits continously due to excitonic coupling extending from 0,71 (La) to 1,92 kK (Lu). The FIR-MIR and resonance Raman spectra are nearly metal independent with the exception of some hypsochromically shifted bands due to C-C and C-N stretching and deformation vibrations of the inner (CN)8 ring. Only the FIR band at 157 cm-1 (La) assigned to the asym. Ln-N stretching vibration is shifted to lower energy.