Synthesis and Crystal Structure of an Oligomeric Lithium Bis(amido)hydridooxidoaluminate Cluster, [{Li(C14H30N2)AlHO1/2}4]

Abstract

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-1-enes 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)A°, b = 10.673(2)A°, c = 28.673(3)A°, β = 115.855(7)°, V = 6887(1)A°3, Z = 4. The complex exhibits an oligomeric structure of crystallographic C2 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 NAlOLi four-membered rings tightly binding two of the diamidochelated aluminate units, with these in turn aggregating further via two of the μ2-hydrides involving lithium atoms.