Reactions of phenylaluminium compounds with E(SiMe 3) 3 (E = P or AS): X-ray crystal structures of Ph 3Al·E(SiMe 3) 3 (E = P or As) and Ph 2(Cl)Al·P(SiMe 3) 3

Abstract

The independent reactions of Ph 3Al with E(SiMe 3) 3 (E = P or As) in 1:1 mole ratios afforded the adducts Ph 3Al·E(SiMe 3) 3 [E = P ( I) and As ( II), respectively. The attempted dehalosilylation reactions between Ph 2AlCl and E(SiMe 3) 3 (E = P or As) in 1:1 mole ratios yielded only the adducts Ph 2(Cl)Al·E(SiMe 3) 3 [E = P( III) and As( IV)]. The adduct Ph(Cl) 2Al·P(SiMe 3) 3 ( V) was isolated from the reaction of equimolar amounts of PhAlCl 2 and P(SiMe) 3. Compounds I–V were characterized by NMR spectroscopy and partial elemental analysis. In addition, the solid-state structures of I–III were determined by single-crystal X-ray analysis. Compound I crystallizes in the monoclinic space group 2 1/ n ( C 2h 5), while II crystallizes in the tricline space group P 1(C i 1) , each with two discrete molecules per asymmetric unit. Crystals of compound III belong to the orthorhombic space group P2 12 12 1 ( D 2 4). Compounds I–III are the first structurally-characterized compounds to contain phenyl-substituted Al centres bonded to heavier pnicogen atoms.