12129-72-5Relevant articles and documents
Arene-Metal Dimer Complexes (C6H6)2V2 and (C6H6)V2; Experiment and Xα Theory. 3
Andrews, Mark P.,Ozin, Geoffrey A.
, p. 1245 - 1256 (1986)
V atoms have been shown in a previous paper (part 1) to react with one or two benzene rings in rare gas matrices to form the respective half-sandwich, (C6H6)V, or the bis(benzene)vanadium complex, (C6H6)2V, depending on the relative concentrations of the various components.In this study, at higher V atom loadings, the corresponding binuclear complexes (C6H6)V2 and (C6H6)2V2 are identified from a combination of a kinetic analysis and V atom concentration study, the results of thermal annealing, and the outcome of V and Cr atom depositions into low-temperature methylcyclohexane solutions of bis(toluene)M (M=V,Cr).Xα-SW calculations were undertaken to provide a qualitative insight into modes of bonding in metal dimer arene molecules.Simplified half-sandwich models were utilized in C6v and C2v symmetry, as implied by stable, known structural analogues.In both cases the molecular orbital divided neatly into three types.The first type related essentially to the benzene ligand itself.The second type was characterized by uniquely metal-metal bonding interactions.These interactions established a basis for inferring metal localized excitations as being at the origin of the electronic absorption spectra seen red-shifted from the main MLCT band.The third type detailed the metal-ligand bonding interactions.The C6v structure showed bonding interactions similar to those of the mono(benzene)vanadium half-sandwich.The C2v molecule showed features in common with metal atoms interacting with a benzene ring which can show latent allyl-like character.The relevance of such a structure to known vanadium dimer molecules incorporating a single fluxional benzene ring is indicated.
Bis(arene)vanadium Anions, a New Class of Organovanadium Complexes: Syntheses, Reactivity towards Carbon Oxides, and Electron Spin Resonance Investigation
Fochi, Giovanni,Runjuan, Xu,Colligiani, Arturo
, p. 2551 - 2554 (1990)
Reduction of bis(arene)vanadium((0) complexes (1) with potassium in co-ordinating ether solvents gives solutions of the corresponding bis(arene)vanadate(-1) derivatives (2a; arene= benzene) and (2b; arene= mesitylene).Solvated potassium salts were isolated in yields depending on the arene ligands and the type of procedure required.The e.s.r. spectra of the reduction mixtures both in 1,2-dimethoxyethane and hexamethylphosphoramide are discussed.Solutuons of K (2a) in tetrahydrofuran are quickly reoxidized by both carbon mono- and di-oxide to give the vanadium(0) complex (1a); C1 and C2 products are formed, the relative yields depending on the concentrations of the reactants.
Bis(arene)vanadium(0) complexes as a source of vanadium(II) derivatives by both disproportionation of the 6-arene)2>+ cations and oxidation of 6-arene)2>
Calderazzo, Fausto,Benedetto, Giuseppe Egidio De,Pampaloni, Guido,Moessmer, Caecilia Maichle,Straehle, Joachim,Wurst, Klaus
, p. 73 - 81 (1993)
The 6-arene)2>+ cation (arene = benzene, toluene or mesitylene) is disproportionate to 6-arene)2 and VII compounds in ether solvents such as THF or 1,2-dimethoxyethane (DME).The extent of disproportionation depends on the nature of both the counteranion and the arene ligand.Addition of the filtered crude reaction mixtures, presumably containing the 6-arene)2> derivatives, to THF gave (arene = benzene or toluene; X = Cl or Br).For X = Cl and arene = toluene, addition to a THF solution of LiI yielded I.The atom connectivity was established for , while I was fully characterized by X-ray diffraction methods.Crystal data: I: monoclinic, space group C2/c (no.15), a 25.199(8), b 13.865(6), c 9.879(4) Angstroem, β 103.98(2) deg, V 3349.3 Angstroem3, Z = 4, Dc 1.523 g cm-3, μ 17.256 cm-1, F(000) = 1560.The vanadium(II) derivative VI2(THF)0.7 was obtained, together with 6-mesitylene)2 in the reaction of 6-mesitylene)2> with THF.By reaction of 6-mesitylene)2> with CPh3X (X = Br or I) in 1,2-dimethoxyethane (DME), the dihalides of vanadium(II), have been isolated in good yields.The crystal and molecular structure of the monomeric cis- of pseudo-octahedral geometry has been studied by X-ray diffraction methods.Crystal data: : monoclinic, space group P21/n (non-standard No.14), a 7.819(4), b 13.150(4), c 15.535(5) Angstroem, β 90.23(3) deg, V 1587.3(1) Angstroem3, Z = 4, Dc 2.017 g cm-3, μ 44.231 cm-1, F(000) = 916.
Bis-arene-vanadium anions as reducing agents towards carbon dioxide and monoxide
Fochi, Giovanni
, p. C1 - C3 (1988)
A novel way of activating an alkali metal for the reduction of CO2 and CO involves dissolving potassium in tetrahydrofuran containing , to give a solution of K as the actual reducing agent.In contact with CO2 or CO, the formal V-I derivative is immediately re-oxidized to the V0 complex and C1 and C2 products are formed.
Ferromagnetism in one-dimensional vanadium-benzene sandwich clusters
Miyajima, Ken,Nakajima, Atsushi,Yabushita, Satoshi,Knickelbein, Mark B.,Kaya, Koji
, p. 13202 - 13203 (2007/10/03)
A molecular beam of multilayer vanadium-benzene organometallic complexes Vn(C6H6)m was produced by a laser vaporization synthesis method. The magnetic moments of the complexes were measured by a molecular beam magnetic deflection technique, and were found to increase with the number of vanadium atoms in the cluster, showing that the unpaired electrons, which occupy the nonbonding dσ orbitals localized on the metal atoms, couple ferromagnetically. These sandwich species represent a new class of one-dimensional molecular magnets in which the transition metal atoms are formally zerovalent. Copyright
