31P to 77Se cross polarization in β-P4Se3

Solid-state selenium-77 NMR

“…Variable temperature 77 Se NMR measurements of PASe glasses from 0 to 40 atom % P have been obtained through the glass transition temperature, T g , of these systems and significant narrowing of the 77 Se NMR signal is found to occur approximately 100 K above T g [293,294]. The use of cross polarization from 31 P to 77 Se has been demonstrated in the inorganic glass, b-P 4 Se 3 ; however, it has not been utilized in establishing PASe connectivity in subsequent studies of either crystalline or amorphous PASe systems [295].…”

A natural abundance 77Se solid-state NMR study of inorganic compounds

“…Moreover, the modest natural abundance of 77 Se also creates a signal-to-noise (S/N) challenge to probe the selenium sites. To overcome the aforementioned challenges, cross-polarisation (CP) experiments have been used with materials containing 1 H and 31 P [5]. The spin magnetisation transfer during the CP period can enhance the 77 Se signal by up to a factor of $g(i)/g( 77 Se), and can also shorten the relaxation period required in the experiment [6].…”

Compositional Evolution of the Structure and Connectivity in Binary P–Se Glasses: Results from 2D Multinuclear NMR and Raman Spectroscopy

“…Although the evolution of the short-range structure of binary P−Se glasses in terms of the P speciation has been studied extensively throughout the glass formation range, little is known regarding the speciation of the Se environments and the intermediate-range order in terms of the connectivity between the constituent structural units. In this regard, the only systematic study, to the best of our knowledge, was carried out by Eckert et al 17 In this study, the intermediate-range order of P−Se glasses was described in terms of the connectivity between the Se−Se segments and the P-containing building blocks on the basis of the results from 31 P− 77 Se spin echo double resonance (SEDOR) and in situ high-temperature 77 Se wideline NMR spectroscopy. 17 Their results were shown to be consistent with a model of random connectivity between these structural moieties.…”

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The atomic structure of binary P x Se 100−x glasses with 5 ≤ x ≤ 70 is investigated using Raman spectroscopy and twodimensional 77 Se and 31 P isotropic/anisotropic correlation nuclear magnetic resonance (NMR) spectroscopy. These spectroscopic results, when taken together, demonstrate that the structure of P x Se 100−x glasses with x ≤ 50 consists primarily of −Se−Se−Se− chain elements, pyramidal P(Se 1/2 ) 3 units, ethylene-like 2/2 SeP− PSe 2/2 units, and Se=P(Se 1/2 ) 3 tetrahedral units.

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