The reduction of MoCl5 with metallic tin in diethyl ether provides a rapid and convenient entry to [MoCl4(OEt2)2] This compound can be transformed easily and in high yields into a variety of other useful synthons The loss of ether in the solid state affords a new and reactive form of MoCl4 Treatment with THF, PMe3 or LiOtBu affords [MoCl4(THF)2], [MoCl4(PMe3)3] or [Mo(OtBu)4] in high isolated yields Treatment with metallic tin in THF affords [MoCl3(THF)3] All of these reactions can be carried out under simple experimental conditions and represent significant improvements relative to previously reported syntheses of the same compounds

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Improved Preparations of Molybdenum Coordination Compounds from Tetrachlorobis(diethyl ether)molybdenum(IV)

Potential energy curves for the broken-symmetry states of the edge-shared bimetallic systems, M2Cl104- (M = Cr, Mo, W), are analyzed using approximate density functional theory. The potential energ...

Electronic structure of face- and edge-shared bioctahedral systems : A comparison of M2Cl93- and M2Cl104-, M = Cr, Mo, W

Chemistry of the Multielectron Excited State

The addition of an [X]+ electrophile to the five-coordinate oxorhenium(V) anion [ReV(O)(apPh)2]− {[apPh]2– = 2,4-di-tert-butyl-6-(phenylamido)phenolate} gives new products containing Re–X bonds. The Re–X bond-forming reaction is analogous to oxo transfer to [ReV(O)(apPh)2]− in that both are 2e– redox processes, but the electronic structures of the products are different. Whereas oxo addition to [ReV(O)(apPh)2]− yields a closed-shell [ReVII(O)2(apPh)2]− product of 2e– metal oxidation, [Cl]+ addition gives a diradical ReVI(O)(apPh)(isqPh)Cl product ([isqPh]•– = 2,4-di-tert-butyl-6-(phenylimino)semiquinonate) with 1e– in a Re d orbital and 1e– on a redox-active ligand. The differences in electronic structure are ascribed to differences in the π basicity of [O]2– and Cl– ligands. The observation of ligand radicals in ReVI(O)(apPh)(isqPh)X provides experimental support for the capacity of redox-active ligands to deliver electrons in other bond-forming reactions at [ReV(O)(apPh)2]−, including radical additions ...

Harnessing redox-active ligands for low-barrier radical addition at oxorhenium complexes.

Polymeric (WCl4)x has been prepared in crystalline form from WCl6 by three new, safer solid-state approaches via mercury (in 83% yield), bismuth (82% yield), or antimony (97% yield) reduction. A modification of a published procedure for reduction of WCl6 with red phosphorus, which improves (WCl4)x purity, is also described. Highly reactive (WCl4)x powder can be prepared in 99% yield via tin reduction of WCl6 in 1,2-dichloroethane. (WCl4)x powder was readily converted in high yields to the known WCl4(MeCN)2 and W2Cl4(OMe)4(HOMe)2. The molecular structure of (WCl4)x, as determined by single-crystal X-ray diffractometry, consists of a polymer of opposite-edge-sharing bioctahedra with alternating short (W(1)−W(1A), 2.688(2) A) and long (W(1)···W(1B), 3.787(3) A) tungsten−tungsten distances. The acute W(1)−Cl(2)−W(1A) angle (69.4(2)°), obtuse Cl(1)−W(1)−W(1A) angle (94.99(12)°), short axial Cl(1)···Cl(1A) nonbonded distance (3.085(10) A, substantially less than twice the Cl van der Waals radius), and short W(1...

Facile Reduction of Tungsten Halides with Nonconventional, Mild Reductants. I. Tungsten Tetrachloride: Several Convenient Solid-State Syntheses, a Solution Synthesis of Highly Reactive (WCl4)x, and the Molecular Structure of Polymeric Tungsten Tetrachloride

F.A. Cotton

Papers

The structures of metal-metal-bonded edge-sharing bioctahedral complexes

Complexes of molybdenum(III) and -(IV) with chloride and tertiary phosphine ligands; an omniumgatherum of new and old results