The electronic effects of substituents on n J PX (n = 2,3;X = H,C) coupling constants and phosphorus chemical shifts;syntheses and spectroscopic investigation of some phosphoramidates

Abstract

New phosphoramidates with the general formulae Me₂NP(O)Cl(p-NHC₆H₄-R) (A) and Me₂NP(O)(p-NHC₆H₄-R)₂ (B), where R = H, CH₃ and NO₂, F, Cl, Br, I, were synthesized and characterized by ¹H, ¹³C, ³¹P NMR and IR spectroscopy and elemental analysis. The electronic effects of donor, acceptor and neutral groups on ⁿJ_PX coupling constants (n = 2, 3; X = H, C) and phosphorus chemical shifts are discussed. NMR data show that only the 4-nitroaniline substituent resulted in the disappearance of all coupling (ⁿJ_PX = 0.0 Hz). Two nearly linear correlations were obtained between para-substituent constants (σ_p) and phosphorus chemical shifts for the two series A and B.