Tin(IV) Tetrachloride Complexes with Bis-(Dialkylamino)phosphoryl Fluoride: A Multinuclear (¹¹⁹Sn, ³¹P, ¹⁹F, and ¹H) NMR Characterization in Solution

The two octahedral complexes SnCl₄·2(O)PF(NR₂)₂ (R = Me or Et) were prepared from reaction of SnCl₄ with the ligand (R₂N)₂P(O)F in anhydrous CHCl₃. The new adducts have been characterized by elemental analysis, IR, and multinuclear (¹¹⁹Sn, ³¹P, ¹⁹F, and ¹H) NMR spectroscopy. The NMR data show that the adducts exist in solution as a mixture of cis and trans isomers with markedly different proportions. When compared with previously described hexamethylphosphoramide (HMPA) and trimethylphosphate (TMPA) analogues, our results indicate that the cis isomer is the predominant species in solution. Low temperature ³¹P and ¹¹⁹Sn NMR spectra show that the compounds partially dissociate in dichloromethane.

KEYWORDS:

• ³¹P NMR
• ¹¹⁹Sn NMR
• ¹¹⁹Sn-³¹P coupling constants
• phosphoryl ligands
• tin tetrachloride

The authors wish to thank Professor A. Baklouti of the Department of Chemistry, Faculty of Sciences of Tunis, University of Tunis El Manar for his valuable help and discussions of this work.

Notes

*Proton–phosphorus coupling (³J_{P - H}) was measured at −25°C.