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 slo wly isomerized to internal olefins, but, in the presence of added hydr ogen, hydrogenolysis to give the alkane is kinetically preferred. Reac tions employing allene and/or 1,3-butadiene are more complex as a resu lt of ligand scrambling, and only the compound W-2(O-c-C5H9)(8)(mu-CH2 CCH2) has been fully characterized. With aldehydes and ketones, insert ion 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 r eaction involving W-2(H)(O-c-C5H9)(7)(HNMe(2)) and cyclopentanone has been fully characterized. With benzophenone, an adduct is formed, whic h in the solid state and in solution is believed to have a terminal hy dride 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 t he reactions between ethyne and a W-2(mu-H)-containing compound has be en fully characterized, but spectroscopic evidence is strongly in favo r of a reaction sequence involving (i) ethyne adduct formation, (ii) i nsertion to form a mu-vinyl ligand, and (iii) further addition of ethy ne and hydride to give a 2-butenylidene complex W-4(OR)(16)(C4H6). Wit h MeC = CMe and [W-2(H)(O-i-Pr)(7)](2), the previously characterized c ompound 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 nitrile s 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)) ha s been structurally characterized. Crystal data for W-2(O-c-C5H9)(7)(e ta(2)-C2H4)(eta(1)-C2H5) at -155 degrees C: P2(1)/a, a = 20.237(5) Ang strom, 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 = 10.61 8(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)-OCP h(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. Cry stal data for W-2(O-i-Pr)(7)(mu-eta(1)-N,eta(1)-N,NCPhCPhN(H)) at = -1 71 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 = 92.4 2(1)degrees, gamma = 68.5(1)degrees, Z = 4.