New phosphorus sulfide cyanides and amides: Assigning phosphorus NMR spectra of polycyclic compounds using low-level ab initio calculations of shieldings

Academic Article

Abstract

  • Oxidation of P4S3 with ICN gives exo,exo- and endo,exo-β-P4S3I2, -β-P4S3(CN)2, and -β-P4S3I(CN) as initial products. Ab initio GIAO calculations of NMR shieldings at the RHF/3-21G* level are sufficient to assign the spectrum of endo,exo-β-P4S3(CN)2 and to confirm the identity of the observed endo,exo-β-P4S3I(CN), which has iodine rather than cyanide in the hindered endo position. Reaction of enantiomerically pure (S)-1-phenyltetrahydroisoquinoline with exo,exo-β-P4S3I2 gives an exo,exo-diamide in which the Cs symmetry of the β-P4S3 cage is lost. The two amido groups, planar at nitrogen, are each capable of two orientations, giving four P-N bond rotamers at 183 K. The 31P NMR spectra of three of these have been fitted, and assigned to particular rotamers by ab initio shielding calculations.
  • Authors

    Digital Object Identifier (doi)

    Pubmed Id

  • 26390171
  • Author List

  • Tattershall BW; Knight JG
  • Start Page

  • 209
  • End Page

  • 214
  • Volume

  • 168-169