CRYSTAL-STRUCTURE AND ABSORPTION-SPECTROSCOPY OF A NEODYMIUM(III) COMPLEX WITH TRIETHYLENETETRAAMINEHEXAACETIC ACID, (TTHA)]CENTER-DOT-2.5NACLO(4)CENTER-DOT-7.617H(2)O

The crystal structure and absorption spectroscopy results of the Na-3[ Nd(TTHA)]. 2.5NaClO(4) . 7.617H(2)O compound are presented. The crysta l structure of the complex was determined by X-ray analysis. Crystals are monoclinic, space group C2/c, with a = 38.446(8) Angstrom, b = 10. 552(2) Angstrom, c = 25.796(5) Angstrom, beta = 130.51(3)degrees, and Z = 4. The structure consists of monomeric (triethylenetetraaminehexaa cetato)neodymate anions, perchlorate anions, sodium cations, and water molecules. The Nd(III) ion adopts a 10-coordinate geometry with six o xygen atoms and four nitrogen atoms from a ligand molecule, which is b est described as a bicapped square antiprism. Absorption spectra of a single crystal were measured at room and liquid helium temperatures. I ntensities of the f-f transitions were analyzed on the basis of Judd-O felt theory. The good correspondence between the spectra of [Nd(TTHA)] (3-) in solution and in the single crystal suggests close similarity o f both coordination polyhedra.