title: Synthesis and structural characterisation of primary amine adducts of gallane, RH2N.GaH3, and of their decomposition products, [RHNGaH2]n(R = Me, n= 3; R =tBu, n= 2).
abstract: Primary amine-gallane adducts, RH(2)N.GaH(3)[R = Me (1) and (t)Bu (2)], have been isolated for the first time from the reaction of [RNH(3)]Cl with LiGaH(4) in Et(2)O solution at ca. 273 K and characterised by their vibrational and (1)H NMR spectra. The structures of single crystals, grown at low temperatures and determined by X-ray diffraction, reveal pseudo-polymeric arrays of RH(2)N.GaH(3) molecules with Ga-N distances of 2.0424(18) and 2.058(5)A for 1 and 2, respectively. The adducts decompose at or near ambient temperatures with the elimination of H(2) and formation of the corresponding monoalkylamido derivative [RHNGaH(2)](n). The crystal structures of these at 150 K consist of either [MeHNGaH(2)](3) molecules with a "skew-boat" conformation for the cyclic Ga(3)N(3) skeleton (3) or [(t)BuHNGaH(2)](2) molecules with a four-membered Ga(2)N(2) core (4), with Ga-N distances averaging 1.986(8) and 1.991(3)A for 3 and 4, respectively. The crystalline solids 1, 3 and 4 feature intermolecular N-H...H-Ga interactions with H...H distances estimated to fall in the range 2.1-2.3 A. The significance of these is discussed.
authors.affiliation: Inorganic Chemistry Laboratory, University of Oxford, South Parks Road, Oxford OX1 3QR, UK.
authors.forename: Sarah
authors.initials: S
authors.lastname: Marchant
authors.forename: Christina Y
authors.initials: CY
authors.lastname: Tang
authors.forename: Anthony J
authors.initials: AJ
authors.lastname: Downs
authors.forename: Tim M
authors.initials: TM
authors.lastname: Greene
authors.forename: Hans-Jörg
authors.initials: HJ
authors.lastname: Himmel
authors.forename: Simon
authors.initials: S
authors.lastname: Parsons