Electron transfer spectra of lanthanide complexes

Abstract Moderately strong, very broad absorption bands observed in dilute lanthanide bromide solutions in nearly anhydrous ethanol are interpreted as electron transfer from the highest filled M.O. to the partly filled 4f shell in the case of Nd(III), Sm(III), Eu(III), Tm(III) and Yb(III). Good agreement is obtained with a theory taking its parameters from the internal 4f transitions. Electron transfer bands are also observed for Eu(III) and Yb(III) dialkyldithiocarbamates, and the narrow bands of similar Pr(III), Nd(III), Sm(III) and Eu(III) complexes are briefly discussed. Relatively narrow 4f→5d transitions are observed in the Ce(III), Pr(III) and Tb(III) bromide solutions and related to the same theory. As expected, no bands are observed for Gd(III), Dy(III), Ho(III), Er(III) and Lu(III).