Crystal Structure of and ab initio Calculations on [(C6H5)(CH3)CH-NH]- P(O)(p-OC6H4CH3)2, Syntheses and Spectroscopic Characterization of N-Benzyl Phosphoramidic Acid (4-Methylphenyl)ester Derivatives

Some new N-benzyl phosphoramidic acid (4-methylphenyl)ester derivatives were synthesized and characterized by 1H, 13C, 31P NMR and IR spectroscopy and elemental analysis. The structure of [(C6H5)(CH3)CH-NH]P(O)(p-OC6H4CH3)2 (2) was investigated. This compound exists in polymeric zigzag chains in the crystalline lattice produced by hydrogen bonding built from two alternating independent molecules. NMR data indicate two diastereotopic p-cresol groups as confirmed by Xray crystallography. Ab initio calculations were performed on the geometry of compound 2 at the UHF/6-311G∗∗ and B3LYP/6-311G∗∗ levels. The optimized structure of each independent molecule contains two different p-cresol groups, in agreement with the experimental results.