Cyclopentadienylmolybdenum(VI) and Molybdenum(V) Oxo Chemistry: New Synthetic and Structural Features

Abstract

Convenient syntheses for Cp, Cp*, and related cyclopentadienyl derivatives ( 4 Cp = C 5 HiPr 4 ; CpЈЈЈ = C 5 H 2 tBu 3 -1,2,4) of formula [(Ring) 2 Mo 2 O 5 ] are described. Compound [Cp 2 Mo 2 O 5 ] was produced in good yields by the rapid oxidation of red [CpMoO 2 ] 4 with PhIO in CH 2 Cl 2 . [Cp* 2 Mo 2 O 5 ] was obtained by CH 3 COOH acidification of aqueous solutions of [Cp*MoO 3 ] − Na + , the latter being generated in a single step from [Cp*MoCl 4 ] and more than 5 equiv. of aqueous NaOH in air. Minor quantities of [Cp*MoO 2 ] 2 were also isolated from this reaction, although the formation of this by-

Nature of (C5Me5)2Mo2O5in water–methanol at pH 0–14. On the existence of (C5Me5)MoO2(OH) and (C5Me5)MoO2+: a stopped-flow kinetic analysis

“…[4][5][6] We have recently reported improved syntheses of the Cp and Cp* compounds (Cp ¼ Z 5 -C 5 H 5 ; Cp* ¼ Z 5 -C 5 Me 5 ), and extended them to the preparation of new derivatives containing the sterically congested C 5 HPr i 4 and 1,2,4-C 5 H 2 Bu t 3 rings. 7 The structures of these compounds display neutral dinuclear units with symmetric Mo-(m-O)-Mo bridges, like the various X-ray structures previously reported for different polymorphs of the Cp* compound. [8][9][10][11] A related complex, Cp*MoO 3 À , has been reported independently by the groups of Geoffroy and Sundermeyer.…”

“…Compounds Cp*2Mo2O5 and Cp*MoO2Cl were prepared according to the literature procedures. 7 pH and conductivity measurements. The pH of the buffer solutions was determined, at 25 °C, with a Methrom 702 SM pHmeter.…”

Mononuclear and Binuclear Cyclopentadienyl Oxo Molybdenum and Tungsten Complexes: Syntheses and Applications in Olefin Epoxidation Catalysis

“…The M=O moieties are readily identified by the IR spectra that show characteristic bands at 941 cm -1 for 1, at 918 and 889 cm -1 for 2 and at 944 and 903 cm -1 for 3. (6). The formation of 6 excludes the occurrence of chloride metathesis and suggests that the attack of the Grignard reagent takes place through electrophilic abstraction of the oxo ligand by magnesium resulting in metal reduction.…”

Organorhenium(vii) and organomolybdenum(vi) oxides: syntheses and application in olefin epoxidation

“…In the following years several other methods for the preparation of CpMoO 2 Cl and Cp*MoO 2 Cl appeared in the literature. [90][91][92][93][94][95] The most convenient method -to our experience -is the oxidative decarboxylation of Cp Mo(CO) 3 Cl (Cp = g 5 -(C 5 H 5 ) and derivatives) with TBHP (see eqn. ( 7)).…”