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)

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.