title: Heterobimetallic Complexes That Bond Vanadium to Iron, Cobalt, and Nickel.
abstract: Zero-valent iron, cobalt, and nickel were installed into the metalloligand V[N(o-(NCH2P((i)Pr)2)C6H4)3] (1, VL), generating the heterobimetallic trio FeVL (2), CoVL (3), and NiVL (4), respectively. In addition, the one-electron-oxidized analogues [FeVL]X ([2(ox)]X, where X(-) = BPh4 or PF6) and [CoVL]BPh4 ([3(ox)]BPh4) were prepared. The complexes were characterized by a host of physical methods, including cyclic voltammetry, X-ray crystallography, magnetic susceptibility, electronic absorption, NMR, electron paramagnetic resonance (EPR), and Mössbauer spectroscopies. The CoV and FeV heterobimetallic compounds have short M-V bond lengths that are consistent with M-M multiple bonding. As revealed by theoretical calculations, the M-V bond is triple in 2, 2(ox), and 3(ox), double in 3, and dative (Ni → V) in 4. The (d-d)(10) species, 2 and 3(ox), are diamagnetic and exhibit large diamagnetic anisotropies of -4700 × 10(-36) m(3)/molecule. Complexes 2 and 3(ox) are also characterized by intense visible bands at 760 and 610 nm (ε > 1000 M(-1) cm(-1)), respectively, which correspond to an intermetal (M → V) charge-transfer transition. Magnetic susceptibility measurements and EPR characterization establish S = (1)/2 ground states for (d-d)(9) 2(ox) and (d-d)(11) 3, while (d-d)(12) 4 is S = 1 based on Evans' method.
authors.forename: Laura J
authors.initials: LJ
authors.lastname: Clouston
authors.forename: Varinia
authors.initials: V
authors.lastname: Bernales
authors.forename: Ryan C
authors.initials: RC
authors.lastname: Cammarota
authors.forename: Rebecca K
authors.initials: RK
authors.lastname: Carlson
authors.affiliation: Max Planck Institut für Chemische Energiekonversion , Stiftstraße 34-36, 45470 Mülheim an der Ruhr, Germany.
authors.forename: Eckhard
authors.initials: E
authors.lastname: Bill
authors.forename: Laura
authors.initials: L
authors.lastname: Gagliardi
authors.forename: Connie C
authors.initials: CC
authors.lastname: Lu