SYNTHESIS AND CHARACTERIZATION OF TITANIUM AND ZIRCONIUM COMPLEXES BEARING DIPHENYLTRIAZENIDO LIGANDS

Treatment of tetrakis (dimethylamido)titanium(IV) and tetrakis(diethyl amido) titanium(IV) with two equivalents of 1,3-diphenyltriazene in he xane afforded, ethylamido)bis(1,3-diphenyltriazenido)titanium(TV) (62% ) and ethylamido)bis(1,3-diphenyltriazenido)titanium(IV) (68%), respec tively, as deep red crystalline solids. Reaction of tetrakis(dimethyla mido)titanium(lv) with more than two equivalents of 1,3-diphenyltriaze ne in refluxing toluene did not lead to substitution of more than two dimethylamido ligands, but only gave extensive;decomposition. Treatmen t of tetrakis(dimethylamido) zirconium(IV) with four equivalents of 1, 3-diphenyltriazene in hexane afforded tetrakis(1,3-diphenyltriazenido) -zirconium(IV) (79%) as a deep red crystalline solid. Crystal structur es of bis(dimethylamido) bis(1,3-diphenyltriazenido)titanium(IV), bis (diethylamido) bis(1,3-diphenyltriazenido) titanium(IV)I and tetrakis( 1,3-diphenyltriazenido)zirconium(IV) were determined. The titanium com plexes-exhibit octahedral coordination spheres with cis-dialkylamido l igands, while the zirconium complex is eight-coordinate with eta(2)-3- diphenyltriazenido ligands. Solution molecular weight measurements for tetrakis(1,3-diphenyltriazenido)zirconium(IV) indicated a monomeric s tructure in benzene, consistent-with the Structural results. (C) 1997 Elsevier Science Ltd.