F. Geoffrey N. Cloke, Peter B. Hitchcock, John F. Nixon, D. James Wilson, Frank Tabellion, Uwe Fischbeck, Fritz Preuss and Manfred Regitz
Two different synthetic routes to the new aromatic 1,2,4-azadiphosphole ring system P2C2But2NR (R = Pri, Pr, Ph, MeC6H4, ButCH2 and cyclohexyl) are presented and the planar structure of P2C2But2NPh, established by a single crystal X-ray diffraction study, is in good agreement with theoretical calculations at the B3LYP/6-311G* level on the parent P2C2H2NH ring.