Substituent Effects on ³¹P NMR Chemical Shifts and ¹J_P–Se of triarylselenophosphates

Abstract

The effect of electron-withdrawing (EW) and electron-releasing (ER) substituents on the ³¹P NMR chemical shifts and the structural parameters of a series of tris-(p-X-aryl)selenophosphates is reported in this article. Similarly to O-aryl phosphates and O-aryl thiophosphates, EW groups attached to aromatic rings induce a shielding effect on the ³¹P NMR signal. After a detailed experimental and theoretical analysis, we confirmed that the selenium atom is the main part responsible for the charge density transfer toward phosphorus through a back-bonding effect. The obtained ¹J_P-Se values for the complete series agree with this observation.

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Keywords:

• DFT calculations
• ³¹P NMR
• selenophosphates
• solvent effect

Acknowledgments

We thank Dr. Barbara Gordillo from Cinvestav for the facilities provided during the collection of the diffraction data and Dr. Oscar García-Barradas for the acquisition of the NMR spectra. The help of Karla Martinez Robinson, Ma. Teresa Cortéz Picasso, and Geiser Cuéllar in obtaining the elemental analyses and the mass spectra is also greatly appreciated. We thank Ariana Teissier and Maryel Contreras for cheerful discussion. The authors are grateful for financial support from Conacyt (Grant 57892). M.S. acknowledges Conacyt for the postdoctoral fellowship.

Notes

^a Standard deviations are in parentheses.

^a Standard deviations are in parentheses.

^a It was not observed due to the low solubility of the compound.