Synthesis, structure, and stability of adducts between phosphide and amide anions and the Lewis acids borane, tris(pentafluorophenyl)borane, and tris(pentafluorophenyl)alane.
The phosphinoborane adduct H(3)P x B(C(6)F(5))(3) can be deprotonated using LiN(SiMe(3))(2) to give the phosphidoborate salt Li[H(2)PB(C(6)F(5))(3)], which was converted to the phosphidodiborates Li[H(2)P{B(C(6)F(5))(3)}(2)] and Li[H(2)P{B(C(6)F(5))(3)}{BH(3)}] by treatment with an equivalent of B(C(6)F(5))(3) or Me(2)S.BH(3), respectively. A series of anions of the form [RR'P{M(C(6)F(5))(3)}{BH(3)}](-), where R = R' = Ph or R= (t)Bu, R' = H, and M = B or Al, were prepared (through treatment of salts Li[RR'P(BH(3))] with the corresponding Lewis acid) and characterized using multinuclear NMR, elemental analysis and X-ray crystallography. The solid state structures of [Li(Et(2)O)(x)][Ph(2)P{M(C(6)F(5))(3)}{BH(3)}] exhibit eta(2)-bonding of the BH(3) group to the cationic lithium center. The attempted preparation of an analogous series with amide cores of the form [R(2)N{B(C(6)F(5))(3)}{BH(3)}](-) proved unsuccessful; among the competing reaction pathways hydride abstraction occurred preferentially to yield Li[HB(C(6)F(5))(3)] and dimers or higher oligomers with the composition (R(2)NBH(2))(n).
Wolfson Materials and Catalysis Centre, School of Chemistry, University of East Anglia, Norwich NR4 7TJ, UK.
Anna-Marie
AM
Fuller
Andrew J
AJ
Mountford
Matthew L
ML
Scott
Simon J
SJ
Coles
Peter N
PN
Horton
David L
DL
Hughes
Michael B
MB
Hursthouse
Simon J
SJ
Lancaster
D000577:Amides / Q000138:chemical synthesis* / Q000737:chemistry*; D000838:Anions / Q000737:chemistry; D001880:Boranes / Q000737:chemistry*; D018360:Crystallography, X-Ray; D006845:Hydrocarbons, Fluorinated / Q000737:chemistry*; D008958:Models, Molecular; D008968:Molecular Conformation; D015394:Molecular Structure; D009942:Organometallic Compounds / Q000737:chemistry*; D010720:Phosphines / Q000737:chemistry*; D013237:Stereoisomerism; D005466:Fluorocarbons
D000577:Amides; D000838:Anions; D001880:Boranes; D006845:Hydrocarbons, Fluorinated; D009942:Organometallic Compounds; D010720:Phosphines; C547050:tris(pentafluorophenyl)alane; D005466:Fluorocarbons; C547049:tris(pentafluorophenyl)borane