A Simple Entry to (η5-C5R5)chlorodioxomolybdenum(VI) Complexes (R = H, CH3, CH2Ph) and Their Use as Olefin Epoxidation Catalysts

Kinetic studies of fluorinated aryl molybdenum(ii) tricarbonyl precursors in epoxidation catalysis

Benzyl substituted molybdenum tricarbonyl complexes displaying CF₃ groups are synthesized and applied as catalyst precursors in olefin epoxidation reactions.

Influence of structural and electronic properties of organomolybdenum(ii) complexes of the type [CpMo(CO)3R] and [CpMo(O2)(O)R] (R = Cl, CH3, CF3) on the catalytic olefin epoxidation

Six compounds of the type [CpMo(CO)₃R] (R = Cl (1), CH₃ (2), CF₃ (3)) and [CpMo(O₂)(O)R] (R = Cl (4), CH₃ (5), CF₃ (6) (Cp = η⁵-cyclopentadienyl)) have been synthesised and characterised.

Stabilization of η3-indenyl compounds by sterically demanding N,N-chelating ligands in the molybdenum coordination sphere

A series of η³-indenyl molybdenum compounds, isostructural with the well-known η³-allyl compounds, was synthesized from the recently established synthon [{(η⁵-4,7-Me₂C₉H₅)Mo(CO)₂(μ-Cl)}₂].

Aryl-substituted organomolybdenum(ii) complexes as olefin epoxidation catalysts

The epoxidation of selected olefins with a benzyl-substituted organomolybdenum complex and its fluorinated counterpart is described.

Cyclopentadienyl molybdenum alkyl ester complexes as catalyst precursors for olefin epoxidation

Piano-stool organomolybdenum complexes of formula [CpMo(CO)₃(CHR²COOR¹)] are described and applied for olefin epoxidation with tert-butyl hydroperoxide as an oxidant.

Speciation of [Cp*(2)M(2)O(5)] in polar and donor solvents

The speciation of compounds [Cp*2 M2 O5 ] (M=Mo, W; Cp*=pentamethylcyclopentadienyl) in different protic and aprotic polar solvents (methanol, dimethyl sulfoxide, acetone, acetonitrile), in the presence of variable amounts of water or acid/base, has been investigated by (1) H NMR spectrometry and electrical conductivity. Specific hypotheses suggested by the experimental results have been further probed by DFT calculations. The solvent (S)-assisted ionic dissociation to generate [Cp*MO2 (S)](+) and [Cp*MO3 ](-) takes place extensively for both metals only in water/methanol mixtures. Equilibrium amounts of the neutral hydroxido species [Cp*MO2 (OH)] are generated in the presence of water, with the relative amount increasing in the order MeCN≈acetone<MeOH<DMSO. Addition of a base (Et3 N) converts [Cp*2 M2 O5 ] into [Et3 NH](+) [Cp*MO3 ](-) , for which the presence of a NH⋅⋅⋅OM interaction is revealed by (1) H NMR spectroscopy in comparison with the sodium salts, Na(+) [Cp*MO3 ](-) . These are fully dissociated in DMSO and MeOH, but display a slow equilibrium between free ions and the ion pair in MeCN and acetone. Only one resonance is observed for mixtures of [Cp*MO3 ](-) and [Cp*MO2 (OH)] because of a rapid self-exchange. In the presence of extensive ionic dissociation, only one resonance is observed for mixtures of the cationic [Cp*MO2 (S)](+) product and the residual undissociated [Cp*2 M2 O5 ] because of a rapid associative exchange via the trinuclear [Cp*3 M3 O7 ](+) intermediate. In neat methanol, complex [Cp*2 W2 O5 ] reacts to yield extensive amounts of a new species, formulated as the mononuclear methoxido complex [Cp*WO2 (OMe)] on the basis of the DFT study. An equivalent product is not observed for the Mo system. The addition of increasing amounts of water results in the rapid decrease of this product in favor of [Cp*2 W2 O5 ] and [Cp*WO2 (OH)].