SPECTROSCOPY AND CRYSTAL-STRUCTURE OF OCTAAQUATETRA-L-ALPHA-ALANINEDIHOLMIUM(III) HEXACHLORIDE [HO2(L-ALPHA-ALAH)4(H2O)8]CL6

Crystals of holmium with L- alpha -alanine, left bracket Ho//2(L- alpha -AlaH)//4(H//2O)//8 right bracket Cl//6, are triclinic. The crystal structure consists of pseudosymmetric dimeric units. Each holmium ion is coordinated by four carboxylate oxygens and four oxygens from the water molecules. The coordination polyhedra around the holmium ions are distorted bicapped trigonal prisms. Absorption spectra at room temperature and 119 K were measured over the range 20 300 - 2690 A. The intensities of f-f transitions were analyzed on the basis of Judd theory.