Syntheses, Characterizations and Crystal Structures of Two New Racemic Amidophosphoesters: rac-(C6H5O)(cyclo-C6H11NH)P(O)N(C4H8)NP(O)(NH-cyclo-C6H11)(OC6H5) and rac-(p-CH3-C6H4NH)P(O)(OC6H4-p-CH3)(OC6H5)

Abstract

The new racemic compounds, rac-diphenyl bis(cyclo-hexylamido)(piperazine)-1,4-diyldiphosphinate, C28H42N4O4P2 (I), and rac-phenyl(p-methylphenyl)(p-tolylamido)-phosphonate, C20H20NO3P (II), were synthesized and characterized by elemental analysis, 31P, 13C, 1H nuclear magnetic resonance, infrared spectroscopy and single-crystal X-ray diffraction analysis. The phosphorus atoms exhibit distorted tetrahedral environment [O]P=O[N][N] in I and [N]P=O[O][O] in II. In compound I, two (C6H5O)P(O)(NH-cyclo-C6H11) fragments are bridged via a NC4H8N linker that accepts chair conformation. In structure II, the environment of the P atom is a result of the linking of one amido and two different phenoxy groups bonded to the P atom. In crystal structure I, adjacent molecules are linked to each other through hydrogen bonds N–H⋅⋅⋅OP in a two-dimensional network along the ab plane, including $$R_{4}^{4}$$ (26) ring motifs, while in structure II, pairs of intermolecular hydrogen bonds N–H⋅⋅⋅OP lead to the formation of centrosymmetric dimers with the $$R_{2}^{2}$$ (8) graph-set motif.