Unveiling the electronic structure peculiarities of phosphine selenides as NMR probes for non-covalent interactions: an experimental and theoretical study

In this work, R₃PSe (R = Me, Et, n-Bu, t-Bu and Ph) were studied experimentally using NMR spectroscopy in solution and the solid-state in combinaton with quantum chemical methods. The study shows that the NMR parameters of these phosphine selenides, such as δP, δSe, and ¹J_PSe, are sensitive to subtle changes in the electronic environment of the P and Se atoms. Consequently, phosphine selenides R₃PSe can serve as promising spectral probes for the detection and quantitative investigation of various non-covalent interactions. Additionally, the variations of R in phosphine selenides influence the observed NMR spectral parameters, primarily through effects such as π-backdonation and hyperconjugation, which have been observed experimentally and confirmed theoretically.