17634-40-1Relevant articles and documents
Preparation of Aluminoborane Analogues of the Lower Boron Hydrides
Himpsl, Francis L.,Bond, Arthur C.
, p. 1098 - 1102 (1981)
The reactions of Al(BH4) with volatile boron hydrides have been found to result in the formation of an unprecedented series of aluminoborane compounds of exceptionally high thermal stability.Reaction of Al(BH4)3 with B2H6 in benzene solution at 100 deg C for 18 h produced a nonvolatile, amorphous, pyrophoric solid of empirical formula AlB4H11.This compound can also be prepared from the reaction of (CH3)3Al with B2H6 under similar conditions.On the basis of the physical and chemical properties of this compound, a polymeric structural arrangement such as that found in (AlH3)x is proposed, with a borane framework similar to that of B5H11.Aluminum occupies the apex (1) BH2 position in the borane cage and , as such, can polymerize through adoption of a six-coordinate, hydrogen-bridging configuration.Reaction of Al(BH4)3 with B5H9 under similar conditions gave another aluminoborane species, AlB5H12, with a similar arrangement of bridging hydrogens between aluminum atoms as proposed for AlB4H11.The reactions of AlB5H12 with H2O and gaseous HCl are unusual in that the dihydroboron cation, BH2+, is apparantly formed in each case.Thermal decomposition of (BH4)Al(B3H8)2, prepared from the reaction of Al(BH4)3 with B4H10, resulted in the formation of a third aluminoborane, AlB6H13.Reactions of AlB4H11 and AlB5H12 with BH4- in diglyme produced the anions AlB5H11- and AlB6H12-, respectively, demonstrating a strong structural similarity between members of the aluminoborane series.
Synthesis and characterization of an Al693- cluster with 51 naked Al atoms: Analogies and differences to the previously characterized Al772- cluster
Koehnlein,Purath,Klemp,Baum,Krossing,Stoesser,Schnoeckel
, p. 4830 - 4838 (2001)
A disproportionation process of a metastable AlCl solution with a simultaneous ligand exchange - Cl is substituted by N(SiMe3)2 - leads to a [Al69{N(SiMe3)2}18]3- cluster compound that can be regarded as an intermediate on the way to bulk metal formation. The cluster was characterized by an X-ray crystal structural analysis. Regarding its structure and the packing within the crystal, this metalloid cluster with 4 times more Al atoms than ligands is compared to the [Al77N(SiMe3)2}20]2- cluster that has been published four years ago. Although there is a similar packing density of the Al atoms in both clusters as well as in Al metal, the X-ray structural analysis shows significant differences in topology and distance proportions. The differences between these - at a first glance almost identical - Al clusters demonstrate that results of physical measuring, e.g., of nanostructured surfaces which carry supposedly identical cluster species, have to be interpreted with great caution.
