Synthesis and Crystal Structure of an Oligomeric Lithium Bis(amido)hydridooxidaoluminate Cluster, [{Li(C₁₄H₃₀N₂)AIHO_1/2}4]

The lithium bis(amido)hydridooxidoaluminate cluster [{Li(C14H30N2)AlHO1/2}(4)] has been synthesized during systematic metallation/hydrometallation studies of a series of 1,4-diazabut-lenes with lithium aluminiumhydride. Formation of the complex is presumably derived from partial hydrolysis of the related lithium bis(amido)dihydridoaluminate and has been characterized using single crystal X-ray diffraction. The complex crystallizes in the monoclinic space group C2/c (No. 15) with a = 25.012(2) angstrom, b = 10.673(2) angstrom, c = 28.673(3) angstrom, beta = 115.855(7)degrees, V = 6887(1) angstrom(3), Z = 4. The complex exhibits an oligomeric structure of crystallographic C-2 symmetry, comprised of complex multicyclic units arising from extensive metal, hydride, oxide and ligand bridging interactions. These associations give rise to edge-fused, non-planar NA1OLi four-membered rings tightly binding two of the diamidochelated aluminate units, with these in turn aggregating further via two of the mu(2)-hydrides involving lithium atoms.