The title compound, BINAP oxide, C44H32O2P2, (I), was synthesized by direct
oxidation of (R)-(+)-2,2'-bis(diphenylphosphino)-1,1'-binaphthyl (BINAP) w
ith tert-butyl hydroperoxide in toluene solution. The angle between the nap
hthyl planes of the binaphthyl group is 94.17 (3)degrees.