The Spectroscopy and Structure of New 1,3,2-Diazaphospholes and 1,3,2-Diazaphosphorinanes

New 1,3,2-diazaphospholes and 1,3,2-diazaphosphorinanes with formula 2,4-Cl-2-C6H3-C(O)NHP(O)X where X = NH(CH2)(2)NH (1), CH3N(CH2)(2)NCH3 (2), NH(CH2)(3)NH (3), and NHCH2C(CH3)(2)CH2NH (4) were synthesized and characterized by H-1, C-13, P-31 NMR, IR spectroscopy, and elemental analysis. The P-31 NMR spectra revealed that the phosphorus atoms are more deshielded in the diazaphospholes than in the diazaphosphorinanes. The C-13 NMR spectrum of 2 indicated that (2)J(PC(aliphatic)) = 14.2Hz for the endocyclic carbon atom is larger than that for the exocyclic CH3 carbon atom (5.2Hz). Furthermore, for diazaphosphorinanes, (3)J(PC(aliphatic)) approximate to 2 x (2)J(PC(aliphatic)). The molecular structure of compound 2 was determined by X-ray crystallography. In this structure, a centrosymmetric dimer is formed via connection of two molecules by strong intermolecular NHcccO hydrogen bonds. The presence of weak intermolecular CHcccO and CHcccCl hydrogen bonds creates a three dimensional polymeric chain in the crystal lattice.