Molybdenum carbonyl derivatives

In a similar manner, Jt-allyl complexes of manganese, iron, and molybdenum carbonyls have been obtained from the corresponding metal carbonyl halides [5], In the case of the reaction of dicarbonyl(r 5-cyclopentadienyl)molybdenum bromide with allyl bromide, the c-allyl derivative is obtained in 75% yield in dichloromethane, but the Jt-allyl complex is the sole product (95%), when the reaction is conducted in a watenbenzene two-phase system. Similar solvent effects are observed in the corresponding reaction of the iron compound. As with the cobalt tetracarbonyl anion, it is... 

In the course of a study of the formation of fluorophosphoranes from chloro-phosphines (22) we observed one exception in the compound chloromethyldi-chlorophosphine, which reacted smoothly with antimony trifluoride to give the flammable fluorophosphine, C1CH2PF2, under conditions where many other chloro-phosphines were invariably converted into fluorophosphoranes. As this fluorophosphine is readily available, its interaction with a metal carbonyl derivative was studied, and cycloheptatriene molybdenum tricarbonyl, obtained from the reaction of molybdenum hexacarbonyl with cycloheptatriene (I, 2), was chosen as a starting compound. 

Molybdenum carbonyl-isocyanide complexes may be obtained as in Section 36.2.2.1.1. In most respects isocyanides behave in a very similar way to carbon monoxide, with which they are isoelectronic. As for the carbonyls, the isocyanide complexes may be regarded as derivatives of [Mo(CNR)6] and have been reviewed comprehensively.la,b... 

From hydroxy acids or acyl derivatives Camphor-10-sulfonic acid, 62 Molybdenum carbonyl, 194 Sodium iodoacetate, 149 Thiophenol, 297... 

In 1980 we published a survey (1) of our major results in this area as of late 1979. These results include extensive work on binuclear CF N PF complexes of cobalt (2,3,4,5) and nickel (6). This paper summarizes our more recent results in this area with particular emphasis on binuclear complexes of chromium, molybdenum, and tungsten as well as some new results on iron carbonyl derivatives. 

The mass spectra of binuclear cyclopentadienylmetal carbonyl derivatives of chromium and molybdenum provide useful indications of the relative strengths of the metal-metal bonds in various compound types. The mass spectrum of [C5H5Cr(CO)3]2 (S. M = Cr) exhibits no bimetallic ions but only monometallic ions such as CsHsC CO) (n = 3,... 

In addition to monocyclopentadienyl dimers, various molybdenocene derivatives can form dimers, as shown in equation (33). This is one example of a vast range of organic ligands that bridge metal-metal bonded complexes. Another example is one of the several products obtained by reaction of diphenylacetylene and molybdenum carbonyl (equation 34). 

The simplicity and power of this approach, known as the method of local oscillating dipoles, was first demonstrated by Orgel (111), who used it to assign the spectra of octahedral molybdenum carbonyl complexes. Very similar arguments were presented simultaneously, but independently, by El-Sayed and Kaesz (59) in a discussion of the spectra of pentacarbonyl halide derivatives of Group VIIA metals. Subsequently, the model has been applied to the assignment of bands in the spectra of numerous octa-... 

Aminosugar-derived glycal 141 was obtained by this method from an appropriate chiral precursor 139 [237], Unexpectedly, however, reaction of tungsten intermediate 140 with tri- -butyltin triflate and triethylamine in ether gave the glycal 141 (in 85% yield) instead of the 1-stannyl derivative (O Scheme 47). The molybdenum carbonyl-triethylamine complex afforded the same product, although in a much lower yield. 

The rearrangement of a-acetylenic alcohols into a-p ethylenic carbonyl derivates has been extensively studied. Different catalysts have been proposed acid catalysts such as sulfuric, hydrochloric or acetic acids which give rise to unselective rearrangements [1,2] and more recently, oxo derivatives of vanadium, molybdenum or tungsten in liquid phase [3]. 

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