Metal Alkoxides - Models for Metal Oxides. 18. Polynuclear Metal Hydrido Alkoxides. Reactions of W4(H)2(O-i-Pr)14 and W2(H)(O-c-C5H9)7(HNMe2) with Carbon-Carbon, Carbon-Oxygen, and Carbon-Nitrogen Multiple Bonds

Reactions between the compounds [W[sub 2](H)(O-i-Pr)[sub 7]][sub 2] and W[sub 2](H)(O-c-C[sub 5]H[sub 9])[sub 7](HNMe[sub 2]) and olefins, alkynes, allene, 1,3-butadiene, ketones, and nitriles have been studied. Of the olefins, only ethene forms a kinetically persistent compound, and W[sub 2](O-c-C[sub 5]H[sub 9])[sub 7]([eta][sup 2]-C[sub 2]H[sub 4])([eta][sup 1]-C[sub 2]H[sub 5]) has been fully characterized. Other [alpha]-olefins are slowly isomerized to internal olefins, but, in the presence of added hydrogen, hydrogenolysis to give the alkane is kinetically preferred. Reactions employing allene and/or 1,3-butadiene are more complex as a result of ligand scrambling, and only the compound W[sub 2](O-c-C[sub 5]H[sub 9])[sub 8]([mu]--CH[sub 2]CCH[sub 2]) has been fully characterized. With aldehydes and ketones, insertion into the metal hydride generally proceeds to give alkoxide ligands, and the complex W[sub 2](O-c-C[sub 5]H[sub 9])[sub 8]([eta][sup 2]-O-c-C[sub 5]H[sub 8]) derived from the reaction involving W[sub 2](H)(O-c-C[sub 5]H[sub 9])[sub 7](HNMe[sub 2]) and cyclopentanone has been fully characterized. With benzophenone, an adduct is formed, which in the solid state and in solution is believed to have a terminal hydride and is formulated as W[sub 2](H)(OR)[sub 7]([eta][sup 2]-OCPh[sub 2]), an analogue of the W[sub 2]([eta][sup 1]-C[sub 2]H[sub 5])([eta][sup 2]-C[sub 2]H[sub 4]) complex. No single product from the reactions between ethyne and amore » W[sub 2]([mu]-H)-contaning compound has been fully characterized. 45 refs., 8 figs., 4 tabs.« less