title: Reactions of H(3)Al.NMe(3) with E(SiMe(3))(3) (E = P, As). Structural Characterization of the Trimer [H(2)AlP(SiMe(3))(2)](3) and Base-Stabilized Adduct [H(2)AlAs(SiMe(3))(2)].NMe(3) and Their Thermal Decomposition toward Nanocrystalline AlP and AlAs, Respectively.
abstract: Dehydrosilylation reactions in diethyl ether between H(3)Al.NMe(3) and E(SiMe(3))(3) afforded for E = P a high yield of the trimer [H(2)AlP(SiMe(3))(2)](3) (1), while for E = As a monomeric base-stabilized adduct [H(2)AlAs(SiMe(3))(2)].NMe(3) (2) as well as its degradation solid product were obtained. No reaction occurred for E = N. The single-crystal X-ray structure determination for 1 yielded a planar six-membered ring of alternating four-coordinated Al and P centers. The structural solution for 2 revealed the monomeric unit [H(2)AlAs(SiMe(3))(2)] stabilized by coordination of NMe(3) at the Al site. Pyrolysis of 1 at 450 degrees C promoted further dehydrosilylation and yielded a product which by XRD spectroscopy showed the onset of AlP crystallinity while at 950 degrees C afforded nanocrystalline AlP with 5 nm average particle size. Pyrolysis of 2 at 450 degrees C resulted in the formation of nanocrystalline AlAs with 2 nm average particle size. Under applied pyrolysis conditions for 1 and 2, the target elimination-condensation pathway via dehydrosilylation was accompanied by other decomposition side reactions and retention of some contaminant residues.
authors.affiliation: Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27514.
authors.forename: Jerzy F.
authors.initials: JF
authors.lastname: Janik
authors.forename: Richard L.
authors.initials: RL
authors.lastname: Wells
authors.forename: Peter S.
authors.initials: PS
authors.lastname: White