SYNTHESIS AND STRUCTURE OF (P,P-DIPHENYLPHOSPHINO)METHYL LITHIUM-TETRAHYDROFURAN

Citation
D. Steinborn et al., SYNTHESIS AND STRUCTURE OF (P,P-DIPHENYLPHOSPHINO)METHYL LITHIUM-TETRAHYDROFURAN, Polyhedron, 17(2-3), 1998, pp. 351-355
Citations number
27
Categorie Soggetti
Chemistry Inorganic & Nuclear",Crystallography
Journal title
ISSN journal
02775387
Volume
17
Issue
2-3
Year of publication
1998
Pages
351 - 355
Database
ISI
SICI code
0277-5387(1998)17:2-3<351:SASO(L>2.0.ZU;2-3
Abstract
Bu3SnCH2PPh2, prepared by reaction of Bu3SnCH2I with NaPPh2 in liquid ammonia and by reaction of Bu3SnCl with LiCH2PPh2/tmeda, reacts with B uLi in hexane as solvent in the presence of a small amount of THF to g ive [{Li(CH2PPh2)(thf)}(infinity)] (4). An X-ray structure analysis re vealed that the (P,P-diphenylphosphino)methyl ligands are arranged in a mu(3)-1:2 kappa(2)C:3 kappa P fashion. Thus, compound 4 exhibits a p olymeric ladder-like structure in which six-membered Li2C2P2 rings wit h a chair conformation and planar four-membered Li2C2 rings are arrang ed alternately. The interplanar angle between the Li2C2 rings and the planar Li2C2 units belonging to the neighbored six-membered rings amou nts to 145.0(4)degrees. The Li-C bonds within the six membered rings a re shorter than those within the four-membered rings [2.21(1) vs 2.39( 1) Angstrom]. The distorted tetrahedral donor set of Li is made up by one phosphorus, one oxygen (tetrahydrofuran) and two methylene carbon atoms. (C) 1997 Elsevier Science Ltd.