title: Crescent-shaped rhodium(I) complexes with bis(o-carboxymethylphenyl)triazenide.
abstract: Reaction of [[Rh(mu-Cl)(CO)2]2] with the triazene ArNNNHAr (Ar = o-CO2MeC6H4) produced the mononuclear complex [RhCl(ArNNNHAr)(CO)2] (1). Complex 1 reacted with KOH in methanol to give the dinuclear compound [[Rh(mu-ArNNNAr)(CO)2]2] (2), which showed a "mu-(1kappaN1,2kappaN3)-ArNNNAr" coordination mode for both bridging ligands. The dinuclear complex [[Rh(mu-ArNNNAr)(CO)2]2] (2) easily undergoes redistribution reactions in which the eight-membered "Rh2(NNN)2" core is broken. Thus, reaction of 2 with the anionic complex (NHEt3)[RhCl2(CO)2] gave the single-bridged complex (NHEt3)[Rh2(mu-ArNNNAr)Cl2(CO)4] (4), while the trinuclear complexes [Rh3(mu-ArNNNAr)(mu-Cl)(mu-CO)Cl(CO)4] (5) and [Rh3(mu-ArNNNAr)2(mu-Cl)(mu-CO)(CO)3] (6) were isolated by addition of the neutral compound [[Rh(mu-Cl)(CO)2]2] to 2, depending on the molar ratio employed. The formation of 5 and 6 involved the loss of carbonyl groups and the coordination of the oxygen atoms of the CO2Me groups. The structures of 4, 5, and 6 have been determined by X-ray diffraction methods, which show the ability of bis(o-carboxymethylphenyl)triazenide to act as bi-, tri-, and tetra-dentate ligand-spanning dinuclear moieties in trinuclear complexes.
authors.affiliation: Departamento de Química Inorgánica, Instituto de Ciencia de Materiales de Aragón, Universidad de Zaragoza-CSIC, E-50009 Zaragoza, Spain. ctejel@posta.unizar.es
authors.forename: Cristina
authors.initials: C
authors.lastname: Tejel
authors.forename: Miguel A
authors.initials: MA
authors.lastname: Ciriano
authors.forename: Gustavo
authors.initials: G
authors.lastname: Ríos-Moreno
authors.forename: Isabel T
authors.initials: IT
authors.lastname: Dobrinovitch
authors.forename: Fernando J
authors.initials: FJ
authors.lastname: Lahoz
authors.forename: Luis A
authors.initials: LA
authors.lastname: Oro
authors.forename: Miguel
authors.initials: M
authors.lastname: Parra-Hake