Syntheses and Spectroscopic Studies of Some New Diazaphospholes and Diazaphosphorinanes. Crystal Structure of 4

New diazaphospholes and diazaphosphorinanes with formula were synthesized and characterized by 1H, 13C, 31P NMR and IR spectroscopy and elemental analysis. The structure of compound 1 has been determined by X-ray crystallography. A one-dimensional polymeric chain was observed in the crystalline lattice produced by intermolecular -P=O. . .H-N- and -C=O. . .H-N-hydrogen bonds. Compounds 1 and 2 contain five-membered rings and show high values for 2J(PNH) and 2J(P,C) coupling constants due to the ring strain. These constants are reduced seriously in compounds with six-membered rings. In compound 6 with CCl3C(O)NH moiety, all phosphorus-hydrogen couplings are zero.