The reactivity of molybdenum pentachloride with ethers: routes to the synthesis of Mo(IV)Cl4 adducts, Mo(V) chlorido-alkoxides and Mo(V) oxydo-chlorides.

Fabio Marchetti, Guido Pampaloni, Stefano Zacchini

Index: Dalton Trans. 42(42) , 15226-34, (2013)

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Abstract

The reactivity of molybdenum pentachloride, 1, with a selection of mono- and diethers was investigated at room temperature in a non-coordinating solvent (dichloromethane). The Mo(IV) complex MoCl4(OMe2)2, 2, was obtained in 75% yield by the reaction of 1 with an excess of Me2O; similarly, MoCl4(κ(2)-L) [L = EtOCH2CH2OEt, 6a; MeOCH2CH(Me)OMe, 6b] were prepared in good yields by 1:1 combination of 1 with the appropriate diether. MoCl5 reacted with OMePh and Et2O affording variable amounts of RCl (R = Me and Et, respectively); MoCl3(OPh)2, 3, was isolated in 60% yield from 1 and OMePh. The reactions of 1 with OMe(t)Bu, O(t)Bu(CH=CH2), MeOCH2CH2OCH2Cl and 1,3-dioxane proceeded with non-selective activation of the organic material. The oxido-complexes Mo2O2Cl4(μ-OMe)2(μ-MeOH), 4, and MoOCl3(MeOH)2, 5, were isolated in modest amounts from 1/OMe(t)Bu, whereas MoOCl3(κ(2)-MeOCH2CH2OCH2Cl), 7, was obtained in 32% yield from 1/MeOCH2CH2OCH2Cl. All of the isolated metal products were characterized by spectroscopic and analytical techniques, and by X-ray diffractometry in the cases of 2, 4, 5, 6b and 7. NMR/GC-MS analyses were carried out in order to outline the fragmentation pathways of the organic reactants.