SYNTHESIS AND CRYSTAL-STRUCTURE OF [TL-2( PHN(3)C(6)H(4)CH(2)C(6)H(4)N(3)PH)(3)], A DINUCLEAR TL-III COMPLEX WITH A NOVEL, BRIDGING BISTRIAZENIDO LIGAND

Tris[di(4,4'-phenyltriazenido)phenylmethane]-di- thallium(III) is form ed by the reaction of T1NO(3) with di(4,4-phenyltriazeno)phenylmethane in the presence of NaOH and air in an ethanol/H2O mixture. The compou nd is obtained as red, needlelike crystals from THF-hexane. It crystal lizes monoclinic, space group I2/a (a=1375.2(5)pm, b=2615(2)pm, c=1957 .0(8)pm, beta=93.49(3)degrees) with four dinuclear complexes in the un it cell. Each complex contains three doubly deprotonated bistriazenido ions (PhN(3)C(6)H(4)CH(2)C(6)H(4)N(3)Ph)(2-) and two Tl3+ ions. The T l ions are each coordinated by three chelating triazenido groups resul ting in a trigonal prismatic coordination of six N atoms. The Tl-N dis tances vary between 227 and 239 pm, all N-N distances of the triazenid o groups are equal within standard deviations with a mean of 130 pm.