N,N '-bis(ethyldiphenylphosphino)ethylenediamine P,P '-dioxide

The molecule of the title compound, C30H34N2O2P2 or Ph2P(O)N(Et)CH2CH2(Et)N(O)PPh2, has crystallographically imposed centrosymmetry. The P - N bond length of 1.656 (2) angstrom is less than the accepted value for a single P - N bond. The P - O bonds [1.4818 (18) angstrom] are also short because of double-bond character.