Synthesis and characterization of some aminophosphonium chlorides

Abstract

R 3P reacts with NR′R″Cl to give good yields of a new homologous series of aminophosphonium chlorides, [R 3PNR′R″]Cl, in which R = Me, Et, n-Pr and Ph; R′ and/or R″ = H, Me. IR, NMR and mass spectral data suggest that the phosphorous is tetracoordinate. When MeN(H)Cl is synthesized by the gas phase reaction of MeNH 2 and Cl 2, an optically active solution of MeN(H)Cl is obtained and the resulting aminophosphonium chlorides exhibit chirality. Electrical conductivity and temperature and concentration dependent NMR studies indicate ion pairing between the [R 3PNR′R″] + and Cl − ions in solution. Quaternization of the phosphorous produces a large 31P downfield chemical shift, a downfield 1H chemical shift for the protons in the alkyl chains and an upfield 13C chemical shift for the carbons in the alkyl chains. α- and β-deshielding and γ-shielding effects are observed in the 13C NMR spectra with substitution on the phosphorous and nitrogen atoms. The mass spectral data, fragment ion identities and fragmentation modes are given for the compounds. Ions corresponding to a variety of P 2N and PN containing species in addition to those associated with fragmentation of the R 3P moieties are observed.