The NMR experiments (1H, 13C{1H}, 31P{1H}, DEPT), IR spectrum and X-ray crystallography of (C6H5)2P(O)[NH-R-(+)CH(C2H5)(C6H5)] were previously studied. Here, two-dimensional NMR spectra (13C-1H HSQC and 1H-1H COSY) are investigated. The 1H-1H COSY shows the most shielded aromatic protons, appeared as overlapped peaks, only correlate with themselves and associate to the phenyl ring of chiral amine. The assignments for the phenyl ring directly attached to phosphorus are done considering the number of cross-peaks; typically the meta-proton shows correlation with three proton signals (belonging to the ortho- and para-protons, besides oneself). The 13C-1H HSQC experiment shows the correlations between each carbon atom and directly attached proton (where it exists). This experiment shows the doublets assigned to the diastereotopic ortho-carbon atoms have lower values of phosphorus- carbon coupling constants (2J) with respect to the doublets assigned to the meta-carbon atoms (3J).

Keywords