Affordable Access

Publisher Website

Substituent effects on the31P NMR chemical shifts of arylphosphorothionates

Authors
Journal
Tetrahedron
0040-4020
Publisher
Elsevier
Publication Date
Volume
62
Issue
11
Identifiers
DOI: 10.1016/j.tet.2005.12.053
Keywords
  • 31P Nmr
  • Ab Initio
  • Back-Bonding
  • Propeller-Type Conformation
  • X-Ray Crystal Structures
  • Arylphosphorothionates
Disciplines
  • Mathematics

Abstract

Abstract Six tris(aryloxy)phosphorothionates substituted in the para position of the aromatic rings were synthesized and studied by 31P NMR, X-ray diffraction techniques and ab initio calculations at a RHF/6-31G** level of theory, in order to find the main structural factors associated with the δ 31P in these compounds. As the electron-withdrawing (EW) ability of the substituents was increased, an ‘abnormal’ shielding effect on δ 31P of the arylphosphorothionates was observed. The analyses of the geometrical properties obtained through both experimental and theoretical methods showed that a propeller-type conformation is preferred for the arylphosphorothionates, except in the case of the tris( O-4-methylphenyl)phosphorothionate, since one of the aromatic rings is not rotated in the same direction as the other two in the solid state. The main features associated with the δ 31P NMR of compounds 1– 6 were a decrease of the averaged O–P–O angle and mainly the shortening of the P S bond length, which is consistent with an increase of the thiophosphoryl bond order as δ 31P values go upfield. On the other hand, comparison of the experimental and calculated bond lengths and bond angles involving α bonded atoms to phosphorus of the six compounds suggested that stereoelectronic interactions of the type n πO-σ* P S , n πO-σ* P-OAr and n πS-σ* P-OAr could be present in the arylphosphorothionates 1– 6 .

There are no comments yet on this publication. Be the first to share your thoughts.

Statistics

Seen <100 times
0 Comments

More articles like this

Substituent and solvent effects on the31P NMR chem...

on Journal of Magnetic Resonance... Jan 01, 1971

A QSPR study of the 31P NMR chemical shifts of pho...

on Journal of chemical informatio... 2001

Conjugative effects in W(CO)5complexed phosphirane...

on Journal of Organometallic Chem... Jan 01, 1995
More articles like this..