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The dissolution of vanadium(V) oxide (V2O5) in various ionic liquids has been studied to determine the complexes formed with respect to melt composition and V2O5 concentration. Vanadium oxide did not dissolve in either 1-n-butyl-3-methylimidazolium tetrafluoroborate or 1-n-butyl-3-methylimidazolium trifluoromethanesulfonate ionic liquids. V2O5 was found to dissolve at temperatures greater than 70 °C in 1-ethyl- and 1-n-butyl-3-methylimidazolium tetrachloroaluminate ionic liquids. Analyses of vanadium-containing melts by 51V, 1H, and 13C NMR and infrared spectroscopy indicate the emergence of different species as a function of melt acidity. In basic and neutral melts, VO2Cl2- and a metavanadate species of the form [(VO3)n]n- are observed. The species VO2Cl2- is the prominent product in basic melts, but as the melt becomes neutral or as the concentration of V2O5 is increased, the concentration of the metavanadate species is found to increase. However, V2O5 has been found to react in acidic melts to form vol...

Vanadium cluster compounds, (VO){sub 6}(O{sub 3}POSiMe{sub 3}){sub 8}Cl (1) [Et{sub 4}P]{sup +}[(V{sub 2}O{sub 3}){sub 2}(O{sub 3}PPh){sub 4}F]{sup {minus}} (2) as well as methylphosphino and butyl analogues of 2 were prepared via reactions of vanadyl compounds with silyl phosphato, phosphonato, or alkyl phosphato compounds. 1 and 2 oxidize cyclohexdiene to benzene. X-ray crystal structures of 1 and 2 and the reduced product of cyclohexadiene oxidation are reported.

Dipicolinate vanadium(V) complexes oxidize lignin model complexes pinacol monomethyl ether (A), 2-phenoxyethanol (B), 1-phenyl-2-phenoxyethanol (C), and 1,2-diphenyl-2-methoxyethanol (D). With substrates having C-H bonds adjacent to the alcohol moiety (B-D), the C-H bond is broken in pyridine-d(5) solvent, yielding 2-phenoxyacetaldehyde from B, 2-phenoxyacetophenone from C, and benzoin methyl ether from D. In DMSO-d(6) solvent the reaction is slower, and both C-H and C-C bond cleavage products are observed for D. The vanadium(IV) products of these reactions have been identified and characterized. Catalytic oxidation of C and D has been demonstrated using air and (dipic)V(O)O(i)Pr. For both substrates, the C-C bond between the alcohol and ether groups is broken in the catalytic oxidation. 1-Phenyl-2-phenoxyethanol is oxidized to a mixture of phenol, formic acid, benzoic acid, and 2-methoxyacetophenone. The products of oxidation of 1,2-diphenyl-2-methoxyethanol depend on the solvent; in DMSO benzaldehyde and methanol are the major products, while benzoic acid and methyl benzoate are the major products obtained in pyridine solvent. Phenyl substituents on the model complex facilitate the oxidation, with relative rates of oxidation DCB.

Bis(trimethysilyl) phosphate and bis(tert-butyl) phosphate make tractible crystalline compounds with certain titanium precursor compounds.

The compounds [(i-Pr) 3 P] 2 RhCl 2 (1), [(i-Pr) 3 P] 2 RhH 2 Cl (2), and [(i-Pr) 3 P] 2 RhHCl 2 (3) have been crystallographically characterized. Compound 1: monoclinic, space group P2 1/ c, a=8.127 (1) A, b=8.953 (2) A, c=16.189 (3) A, β=92.52 (1) o , 0=0.020, R w =0.020. Compound 2: triclinic, space group P1, a=11.807 (2) A, b=14.681 (3) A, c=14.743 (3) A, α=111.66 (1) o , β=92.18 (1) o , γ=93.29 (1) o , R=0.026 , R w =0.027

The importance of the `Butox` process (the aireal oxidation of butane to maleic anhydride) and the phosphato-vanadium material (`VPO`) that catalyzes it has inspired considerable research into phosphato-vanadium chemistry. Phosphatovanadium and phosphonatovanadium compounds known to date all have bridging phosph(on)-ato groups. The new diethyl phosphato compound (dipic)V({double_bond}O)(O{sub 2}P(OEt){sub 2}) (2) has been prepared by removing the alcohol from mixtures of diethyl hydrogen phosphate and the alkoxy compound [(dipic)V-({double_bond}O)(O{sup i}Pr)]{sub 2}{center_dot}HO{sup i}Pr (1). Compound 2 is dimeric in the solid state with each diethyl phosphato group bridging two vanadium centers, but each diethyl phosphato group is strongly bonded to only one vanadyl center and is surprisingly easily displaced by reaction with alcohols.

Two tetramethylammonium salts of new fluoroaluminate species have been crystallographically characterized and reveal structural motifs previously unknown for such species. The elusive tetrahedral [AlF[sub 4][sup [minus]]] anion is present in the anhydrous material while the monohydrate reveals fluoride edge-shared octahedral aluminium complexes with extensive hydrogen-bonding both intra- and intermolecularly for the new, discrete [Al[sub 2]F[sub 8](H[sub 2]O)[sub 2][sup 2[minus]]] anions. The two salts readily interconvert depending on the water content of their environment.