New versatile phosphorus ligands containing SPNSO skeleton - synthesis and characterization of (SPPh2)(O2SR)NH acids (R=Me, C6H4Me-4) and their alkaline metal salts. Crystal and molecular structures of (SPPh2)(O2SR)NH

New phosphorus ligands of the type (SPPh₂)(O₂SR)NH R=Me (1), C₆H₄Me-4 (2)] were prepared as white crystalline solids using the reactions between LiHN(S)PPh₂] and RSO₂Cl. They were easily converted into their alkali metal salts, M(SPPh₂)(O₂SR)N] (M=Li, Na, K). Both the free acids and their alkali metal salts were characterised by multinuclear (¹H, ¹³C, ³¹P) NMR spectroscopy. The molecular structures of the free acids were established by single crystal X-ray diffraction. They crystallize in the tetragonal space group I4₁/a (1) and the triclinic space group P−1 (2), respectively. In both compounds the acidic proton is attached to nitrogen and the molecular units are associated through SO?H-N intermolecular hydrogen bonding H?O 2.216 in 1 and 2.029 Å in 2]. A supramolecular chain-like structure is formed in 1 and dimeric units are built in 2. For both compounds a conformation close to syn-syn can be considered for the SP(C)₂-N-SC(O)₂ fragment.