Synthesis and Reactivity of Amidoaluminum Hydride Compounds as Potential Precursors to AlN.

Autor: Hodgson, Michael C., Khan, Masood A., Wehmschulte, Rudolf J.
Předmět:
Zdroj: Journal of Cluster Science; Dec2002, Vol. 13 Issue 4, p503, 18p, 4 Diagrams, 4 Charts
Abstrakt: A new series of amidoaluminum hydride complexes H[sub n]AI[N(SiHMe[sub 2])[sub 2]][sub 3-n] NMe[sub 3] (1, n=2; 2, n= 1), AI[N(SiHMe[sub 2])[sub 2]][sub 3] (3), and [H[sub 2]A1N(SiHMe[sub 2])[sub 2]][sub 2] (4) were prepared by the metallation of tetramethyldisilazane (Me[sub 2]HSi)[sub 2]NH with either H[sub 3]A1·NMe[sub 3] or H[sub 3]Al·2Et[sub 2]. The molecular structures of 1 and 2 were shown by X-ray crystal structure determination to be monomeric Lewis acidbase adducts with four coordinate aluminum centers and terminal amido groups. The molecular structure of 4 was found to be a dimer with bridging disilylamides in the solid state. Attempts to obtain crystals of [H[sub 2]A1N(SiMe[sub 3])[sub 2]][sub 2], a bulkier analogue of 4, led to the isolation of the unusual alumoxane μ²-(Me[sub 3]Si)[sub 2] N-(A1H[sub 2])[sub 2]-μ³-O-Al(H)N(SiMe[sub 3])[sub 2] · OEt[sub 2] (6) in moderate yields. Thermolysis of 1 and 2 resulted only in the formation of ligand exchange and decomposition products, whereas thermolysis of 4 at 80°C afforded 1 equivalent of Me[sub 2]SiH[sub 2] and a new species formulated as the imide complex [HAINSiMe[sub 2]H][sub n] (7). Thermolysis of 4 in the presence of A1H[sub 3] · NMe[sub 3] gave Me[sub 2]SiH[sub 2] and 7 at a higher reaction rate even at a lower temperature. [ABSTRACT FROM AUTHOR]
Databáze: Complementary Index
Externí odkaz: