POLYNUCLEAR METAL HYDRIDO ALKOXIDES - REACTIONS OF W-4(H)(2)(O-I-PR)(14) AND W-2(H)(O-C-C5H9)(7)(HNME(2)) WITH CARBON-CARBON, CARBON-OXYGEN, AND CARBON-NITROGEN MULTIPLE BONDS

Reactions between the compounds [W-2(H)(O-i-Pr)(7)](2) and W-2(H)(O-c-C5H9)(7)(HNMe(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-2(O-c-C5H9)(7)(eta(2)-C2H4)(eta(1)-C-2-H-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-2(O-c-C5H9)(8)(mu-CH2CCH2) has been fully characterized. With aldehydes and ketones, insertion into the metal hydride generally proceeds to give alkoxide ligands, and the complex W-2(O-c-C5H9)(8)(eta(2)-O-c-C5H8) derived from the reaction involving W-2(H)(O-c-C5H9)(7)(HNMe(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-2(H)(OR)(7)(eta(2)-OCPh(2)), an analogue of the W-2(eta(1)-C2H5)(eta(2)-C2H4) complex. No single product from the reactions between ethyne and a W-2(mu-H)-containing compound has been fully characterized, but spectroscopic evidence is strongly in favor of a reaction sequence involving (i) ethyne adduct formation, (ii) insertion to form a mu-vinyl ligand, and (iii) further addition of ethyne and hydride to give a 2-butenylidene complex W-4(OR)(16)(C4H6). With MeC = CMe and [W-2(H)(O-i-Pr)(7)](2), the previously characterized compound W-2(O-i-Pr)(6)(mu-C(4)Me(4))(eta(2)-C(2)Me(2)) is formed with the elimination of i-PrOH and propene. The reactions employing nitriles give products derived from hydride reduction of the coupled nitriles, and the compound W-2(O-i-Pr)(7)(mu-eta(1)-N,eta(1)-N-NCPhCPhN(H)) has been structurally characterized. Crystal data for W-2(O-c-C5H9)(7)(eta(2)-C2H4)(eta(1)-C2H5) at -155 degrees C: P2(1)/a, a = 20.237(5) Angstrom, b = 9.938(5) Angstrom, c = 21.660(5) Angstrom, beta = 113.91(1)degrees, Z = 4. Crystal data for W-2(O-c-C5H9)(8)(mu-CH2CCH2) at -171 degrees C: P2(1)/n, a = 18.070(5) Angstrom, b = 24.432(6) Angstrom, c = 9.848(2) Angstrom, beta = 90.19(1)degrees, Z = 4. Crystal data for W-2(O-c-C5H9)(8)(eta(2)-O-C-C5H8) at -175 degrees C: P2(1)/c, a = 10.618(1) Angstrom, b = 20.824(2) Angstrom, c = 22.154(5) Angstrom, beta = 115.22(1)degrees, Z = 4. Crystal data for W-2(H)(O-i-Pr)(7)(eta(2)-OCPh(2)) at -172 degrees C: P2(1)/n, a = 11.899(5) Angstrom, b = 19.928(8) Angstrom, c = 15.956(7) Angstrom, beta = 91.61(2)degrees, Z = 4. Crystal data for W-2(O-i-Pr)(7)(mu-eta(1)-N,eta(1)-N,NCPhCPhN(H)) at = -171 degrees C: P ($) over bar l, a = 18.688(4) Angstrom, b = 22.186(5) Angstrom, c = 10.368(2) Angstrom, alpha = 94.39(1)degrees, beta = 92.42(1)degrees, gamma = 68.5(1)degrees, Z = 4