UNPRECEDENTED COORDINATION OF THE ALH2+ AND NA+ CATIONS IN THE STRUCTURE OF THE ORGANOMETALLIC COMPLEX [ALH2(OC4H8)4][(ETA-5-C5H5)3YB(MU-NA)YB(ETA-5-C5H5)3]

Interaction of Na[Yb(C5H5)3] with aluminum hydride in THF yields the ionic complex [AlH2(C4H8O)4][(C6H5)3Yb(Na)Yb(C5H5)3](1) and NaAlH4. This reaction apparently proceeds as an ionic exchange with the products of the autoionization of aluminum hydride in the solvent. Crystals of 1 are monoclinic, with a = 8.494(2) angstrom, b = 15.214(3) angstrom, c = 18.242(4) angstrom, gamma = 92.45(2)-degrees, Z = 2, rho(calco) = 1.516 g cm-3, and space group P2(1)/b. The structure was solved by the Patterson method and refined by full-matrix least-squares procedures to R = 0.040 and R(w) = 0.043 for 2700 reflections with I > 3sigma(I). The metal atoms in 1 are bound by ionic bonds, forming a bent complex.