title: Transition metal complexes of 3-cyano- and 3-nitroformazans.
abstract: The synthesis and characterization of six transition metal complexes of 3-cyano- and 3-nitroformazans are described. Three different formazans were reacted with nickel(II) to produce complexes with bidentate formazan ligands. Mononuclear NiL2 (L = deprotonated formazan) or binuclear hydroxo-bridged (LNi)2(mu-OH) 2 species were produced depending on the steric bulk on the formazan N-aromatic substituents. 1,5-Bis(2-methoxyphenyl)-3-cyanoformazan acts as a tetradentate monoanionic ligand in a copper(II) complex, whereas the analogous 1,5-bis(2-hydroxyphenyl)-3-cyanoformazan binds as a trianion in a tetradentate manner to Fe(III) and Co(III). Crystal structures-the first examples of metal complexes of cyano- or nitroformazans-as well as the electronic spectra of the complexes are discussed in relation to each other as well as that of the uncoordinated formazans.
authors.affiliation: Department of Chemistry, University of Victoria, Victoria, British Columbia, Canada.
authors.forename: Joe B
authors.initials: JB
authors.lastname: Gilroy
authors.forename: Brian O
authors.initials: BO
authors.lastname: Patrick
authors.forename: Robert
authors.initials: R
authors.lastname: McDonald
authors.forename: Robin G
authors.initials: RG
authors.lastname: Hicks