Diphosphanes derived from phobane and phosphatrioxa-adamantane: similarities, differences and anomalies.

The homodiphosphanes CgP-PCg (1) and PhobP-PPhob (2) and the heterodiphosphanes CgP-PPhob (3), CgP-PPh(2) (4a), CgP-P(o-Tol)(2) (4b), CgP-PCy(2) (4c), CgP-P(t)Bu(2) (4d), PhobP-PPh(2) (5a), PhobP-P(o-Tol)(2) (5b), PhobP-PCy(2) (5c), PhobP-P(t)Bu(2) (5d) where CgP = 6-phospha-2,4,8-trioxa-1,3,5,7-tetramethyladamant-9-yl and PhobP = 9-phosphabicyclo[3.3.1]nonan-9-yl have been prepared from CgP(BH(3))Li or PhobP(BH(3))Li and the appropriate halophosphine.