Zero-valent complexes, molybdenum

Intramolecular Oxidation of Zero-Valent Complexes of Molybdenum(O) and TungstentO)... 

Mo(CO)6] complex. The molybdenum intermediates were studied using in situ IR as part of an extensive mechanistic investigation. The following intermediates were identified in the reaction mixture [Mo(CO)6], [Mo(CO)5l] and [Mo(CO)4l3]. Hydrogen, which at low concentrations increases the rate of the reaction, was found to reduce [Mo(CO)4l3] to the zero-valent complex, thus regenerating the catalyst. ... 

C. Preparation of Six- and Seven-Coordinate Complexes of Molybdenum(ll) and Tungsten(ll) by Halogen Oxidation of Zero-Valent Carbonyl Complexes Containing at Least One Other Donor Ligand... 

Zero-valent ruthenium complexes (arene)Ru(PRg)2 (PR3 = tertiary phosphine), isoelectronic with the molybdenum complexes (CgHg)Mo-(PR3)3 182), have not yet been reported. However, the hydride cation (XXVII), isoelectronic with the molybdenum hydride cations [(CgHg)-Mo(PR3)3H] 182), has been obtained from the dissociation of [RuH-(PPh3)JPFg in dichloromethane solution 364). 

ZERO-VALENT ISOCYANIDE COMPLEXES OF CHROMIUM, MOLYBDENUM, AND TUNGSTEN... 

A general method of preparation of the zero valent metal trifluorophosphines is by ligand replacement. Under high PF3 pressure, for example, the chromium or molybdenum compound can be prepared from the dibenzene derivatives (8.175). Carbon dioxide is also displaced under high pressure (8.176), although the reaction is reversible. Under some conditions, partial replacement can be effected to produce complexes of type M(CO) j (PFslx-... 

A hydride is one of the simplest nucleophiles, and Casey ° and Gladysz have prepared kinetically stable formyl complexes by the direct attack of hydride on a number of neutral chromium-, molybdenum-, and iron-carbonyl complexes (Equation 11.2). Although these complexes are relatively electron rich, because they possess zero-valent metal centers, the negative charge in the product can be stabilized by the remaining -ir-ac-cepting CO ligands. 

C. Other Zero-Valent Isocyanide Complexes of Chrominm, Molybdenum, and Tungsten... 

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