Diastereomers (RC,SP)- and (RC,RP)-S-methyl P-(3-azido­prop­yl)-N-[(1R)-1-phenyl­ethyl]phospho­namido­thio­ate

Diastereoisomers of the title organophospho­rus compound, C12H19N4OPS, denoted RCSP, (I), and RCRP, (II), were structurally characterized and compared. Asymmetric phosphorus compounds are of interest with regard to the use of these systems as possible protein probes via the stereoselective delivery of an azide group tethered to the P atom into key protein regions. The diastereomers were produced in a 1:1 mixture and isolated by chromatography. Although both isomers crystallize in the same space group with superficially similar cell constants, conformational and packing differences are pronounced. Despite the conformational differences, strong inter­molecular hydrogen bonding links both isomers into chains parallel to the a axis [N⋯O = 2.8609 (18) and 2.966 (3) A in (I) and (II), respectively], with C—H⋯π inter­chain inter­actions of ca 3.5 A.