A. Karacar et al., Oxidation reactions of 1,8-bis(phosphino)naphthalenes: Syntheses and molecular structures of bis(phosphine oxides) and of a bis(phosphine sulfide), HETEROAT CH, 12(2), 2001, pp. 102-113
A series of naphthalenediyl-1,8-bis(phosphine oxides) 1-RR'P(:O)(C10H6)-8-P
(:O)RR' (R=R'=Me (2a), Et(2b), iPr (2c), Cy (2d), Ph (2f) and R = tBu, R' =
Ph (2e) was prepared by oxidation of the corresponding bis(phosphines) 1a-
f with molecular oxygen or H2O2. (H2N)(2)C(:O) and characterized by NMR and
IR spectroscopy, mass spectrometry, and elemental analysis (2a, 2b, 2d-f).
X-ray crystal structure analyses were performed for 1,8-bis(dimethylphosph
inyl)naphthalene (2a), (RR,SS)-1,8-bis-(phenyl-tert-butylphosphinyl)naphtha
lene (2e) and 1,8-bis(diphenylphosphinyl)naphthalene (2f). Treatment of 1,8
-bis(diphenylphosphino)naphthalene (dppn, 1f) with an excess of sulfur in h
ot toluene afforded the bis(phosphine sulfide) 1-Ph2P(:S) (C10H6)-8-P(:S)Ph
-2 (dppnS(2), 3f) the structure of which was elucidated by X-ray crystal st
ructure analysis. The geometries of the compounds 2a, 2e, 2f, and 3f reveal
ed an increase of strain from the corresponding bis(phosphines). In each ca
se, the proximity of the P(:X)R-2 groups (X = O, S) led to distortion, the
main feature of which was the out-of-plane displacement of the P atoms. (C)
2001 John Wiley & Sons, Inc.