Hydroxo complexes molybdenum

The reaction of [MoO(H20)(CN)4] with 1,10-phenanthroline (211) and 2,2 -dipyridyl (215) has also been studied by means of reaction kinetics. It is clear that there are still uncertainties and questions regarding the mechanism of the reaction of these bidentate ligands For example, why is the reaction of the molybdenum complex faster at high pH values at which there is less of the aqua and more of the hydroxo) complex in solution (211) Scheme 5 was proposed for reaction with 2,2 -bipyridyl (215). 

The use of /r-hydroxo or ju-alkoxo bridged polynuclear complexes of chromium, molybdenum, tungsten, or rhenium in this route leads to the formation of monomeric bis(NHC) complexes, to the elimination of hydrogen, and to the partial oxidation of the metal [Eq.(ll)]. Chelating and nonchelating imidazolium salts as well as benzimidazolium and tetrazolium salts can be used. 

The decomposition of the peroxometallacycle (72a) or (72b) occurs in a way different from that previously shown to occur in the epoxidation of alkenes by molybdenum-peroxo complexes (equation 26). The three possibilities are shown in equations (58)-(60) and involve (a) a [C-/6, C-a] hydride shift which directly produces the methyl ketone and the rhodium-oxo complex, or the hydroxo species from (72b equation 58) (b) a [C-/3,0-/3] hydride shift which gives enol (equation... 

One of the systems which fulfills these requirements is the EDTA complex of Mo (III), /A-acetato-di-/r-hydroxo-/x( N,N ) ethylenediaminetet-raacetatobis[molybdenum(III)]. The complex was originally prepared but incorrectly formulated by Kloubek and Podlaha (28). Its solid-state structure has recently been determined by Sykes et al. (Figure 2). Preliminary results in our laboratory have demonstrated that this compound... 

CuestaL, Gerbino DC, HeviaE, etal. Reactivity of molybdenum and rhenium hydroxo-carbonyl complexes toward organic electrophiles. Ckem EurJ. 2004 10 1765-1777. Hevia E, PerezJ, Riera V, Miguel D. New octahedral rhenium (I) tricarbonyl amido complexes. OrganometaUics. 2002 21 1966-1974. 

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