Tertiary phosphine adducts of alane and gallane

Article abstract of DOI:10.1016/0022-328X(93)80105-K

Thermally stable mono-tri-t-butylphosphine adducts of alane and gallane, H3MP¹Bu3 (M = Al, 1; M = Ga, 2) and the gallane rich adducts of 1,2-bis(diisopropylphosphino)ethane and 1,2-bis(diphenylphosphino)ethane, <(H3Ga)2<> (R = ⁱPr, 3; R = Ph, 4), have been prepared from LiMH4/HCl/phosphine; reactions involving H3MNMe3/P^tBu3 also yield 1 and 2, for the former via a mixed donor ^tBu3PAl(H)3NMe3 (5), which decomposes to 1 and NMe3 at ca. 40 deg C; compounds 1 and 2, and the previously reported alane analogue of 3, viz. <(H3Al)2<(PⁱPr2CH2)2>> (6) have been shown to be four coordinate (Al-P, 2.471(3) and 2.451(3) Angstroem, 1 and 6; Ga-P 2.444(6) Angstroem, 2).Ab initio calculations on relevant model systems, H3GaPMe3 (DZP level) and H3Al(PR3)2 (R = H or Me; D95^* level) are reported, Ga-P 2.550 Angstroem, and Al-P 2.828 Angstroem (R = H), 2.786 Angstroem (R = Me).