title: Linear and nonlinear two-coordinate vanadium complexes: synthesis, characterization, and magnetic properties of V(II) amides.
abstract: The synthesis and characterization of the first stable two-coordinate vanadium complexes are described. The vanadium(II) primary amido derivative V{N(H)Ar(iPr6)}2 [Ar(iPr6) = C6H3-2,6-(C6H2-2,4,6-iPr3)2] (1) was synthesized via the reaction of LiN(H)Ar(iPr6) with the V(III) complex VCl3·2NMe3 or the V(II) salt [V2Cl3(THF)6](+)I(-) in a 2:1 and 4:1 stoichiometry, respectively. Reaction of the less crowded LiN(H)Ar(Me6) with [V2Cl3(THF)6](+)I(-) afforded V{N(H)Ar(Me6)}2 [Ar(Me6) = C6H3-2,6-(C6H2-2,4,6-Me3)2] (2), which has a nonlinear [N-V-N = 123.47(9)°] vanadium coordination. Magnetometry studies showed that V{N(H)Ar(iPr6)}2 and V{N(H)Ar(Me6)}2 have ambient temperature magnetic moments of 3.41 and 2.77 μB, respectively, which are consistent with a high-spin d(3) electron configuration. These values suggest a significant spin orbital angular momentum contribution that leads to a magnetic moment that is lower than their spin-only value of 3.87 μB. DFT calculations showed that the major absorptions in their UV-vis spectra were due to ligand to metal charge transfer transitions. Exposure of the reaction mixture for 2 to dry O2 resulted in the formation of the diamagnetic V(V) oxocluster [V{N(H)Ar(Me6)}2]2(μ-O-Li-O)2 (3).
authors.affiliation: Department of Chemistry, University of California-Davis, 1 Shields Avenue, Davis, California 95616, USA.
authors.forename: Jessica N
authors.initials: JN
authors.lastname: Boynton
authors.forename: Jing-Dong
authors.initials: JD
authors.lastname: Guo
authors.forename: James C
authors.initials: JC
authors.lastname: Fettinger
authors.forename: Christopher E
authors.initials: CE
authors.lastname: Melton
authors.forename: Shigeru
authors.initials: S
authors.lastname: Nagase
authors.forename: Philip P
authors.initials: PP
authors.lastname: Power