Vanadium Organometallics

Reaction ofp-Toluenesulfonylamide and M(NMe2)4(M = Ti, V): Generation of Electron-Deficient Imido Complexes of Early Transition Metals

“…Although it is a generally clean transformation in related arylimido complexes V(NAr)Cl 2 (NHMe 2 ) 2 , attempted displacement of NHMe 2 ligands in 5 by pyridines in dichloromethane failed, with formation of the known, reduced, vanadium(III) complexes VCl 3 Py 3 and V 2 OCl 4 Py 6 . It is conceivable that these vanadium(III) complexes are formed along with other uncharacterizedorganic and/or inorganicproducts via ligands redistribution or redox reactions that are common features in vanadium chemistry . Nevertheless, we were unable to isolate other species out of the reaction, but this unexpected reactivity is currently under further examination in our group.…”

Vanadium complexes with N-heterocyclic vinylidene ligands

“…2). The V–C bond lengths ( 2 :1.706(2) Å; 4 :1.704(2) Å) are in-between those found for vanadium alkylidene complexes (V–C ∼ 1.79–1.92 Å) 35 and vanadium alkylidyne complexes (V–C ∼ 1.68 Å). 35–37 The VC–C bonds have lengths of 1.412(3) Å ( 2 ) and 1.423(2) Å ( 4 ).…”

“…The V–C bond lengths ( 2 :1.706(2) Å; 4 :1.704(2) Å) are in-between those found for vanadium alkylidene complexes (V–C ∼ 1.79–1.92 Å) 35 and vanadium alkylidyne complexes (V–C ∼ 1.68 Å). 35–37 The VC–C bonds have lengths of 1.412(3) Å ( 2 ) and 1.423(2) Å ( 4 ). These values are significantly larger than what was reported for the exocyclic CCH 2 bonds of the corresponding N-heterocyclic olefins (1.331(8) and 1.361(1) Å).…”

Reactivity of B(C6F5)3 with Simple Early Transition Metal Alkoxides: Alkoxide-Aryl Exchange, THF Ring-Opening, or Acetonitrile CC Coupling

“…The chemistry of the strongly Lewis acidic tris(pentafluorphenyl)borane B(C 6 F 5 ) 3 is the subject of numerous applications. Although the main interest was its established role in the formation of cationic derivatives for polymerization, different organic, organometallic, and catalytic applications have been reported in the past few years. − In our group, we have used B(C 6 F 5 ) 3 in conjunction with early transition metal group 4 and 5 precursors to afford new and original organometallic complexes related to alkyl abstraction, reactivity of small molecules (CO, , water , ) and nitriles. − During this research, while attempting to generate metal-oxo·B(C 6 F 5 ) 3 adducts or cationic species from oxo-vanadium(V) amido or alkoxo precursors treated with B(C 6 F 5 ) 3 , we found with others that in certain alkoxide complexes an exchange reaction between a C 6 F 5 group of B(C 6 F 5 ) 3 and an alkoxy ligand attached to a metal can occur, which results in the formation of an organometallic complex containing a metal-C 6 F 5 moiety, as depicted in Scheme . − Particularly, the reaction of [VO(OCH 2 CF 3 ) 3 ] 2 in pentane with 2 equiv of B(C 6 F 5 ) 3 afforded the organometallic vanadium dimer complex [VO(μ-OCH 2 CF 3 )(OCH 2 CF 3 ) 2 (C 6 F 5 )] 2 , a rare example of a structurally established alkyl-vanadium(V) complex . The alkoxide−aryl exchange reaction presumably proceeds through a zwitterionic [M-μ-OR-B(C 6 F 5 ) 3 ] adduct or a cationic [M] + [B(OR)(C 6 F 5 ) 3 ] − intermediate (Scheme ).…”