189556-95-4Relevant articles and documents
Products and Mechanisms in the Oxidation of Phosphorus by Sulfur at Low Temperature
Jason, Mark E.,Ngo, Toan,Rahman, Shahidur
, p. 2633 - 2640 (2008/10/09)
The oxidation of phosphorus by sulfur at low temperatures (8 diradical. This proposal is supported by the observed rate at which the sulfldes are formed and the distribution of the sulfide product stoichiometries. Photoinitiation of this oxidation at 0 °C produces a similar array of sulfldes. The differences in the product distributions between the thermal and photochemical processes facilitate the understanding of the mother-daughter relationships between the products. The effects of oxidation by sulfur and reduction by phosphorus have been determined for several of the known phosphorus sulfides. The characterizations of phosphorus compounds in molten mixtures of phosphorus and sulfur were performed by 31P NMR and Raman spectroscopy directly on the reaction mixtures.
Multiphase characterization of phosphorus sulfides by multidimensional and MAS-31P NMR spectroscopy. Molecular transformations and exchange pathways at high temperatures
Bjorholm,Jakobsen
, p. 27 - 32 (2007/10/02)
High-temperature 1D and 2D exchange 31P-NMR spectra of melts of pure and well-defined phosphorus sulfides show that, e.g., β-P4S5 or mixtures of P4S3 and sulfur transform into mixtures of at least eight different P4Sn (n = 3-7) species which are identified and quantified. Transformations and exchange pathways between the different P4Sn species in the melts are revealed by the 2D exchange 31P-NMR spectra at 225-250 °C. Furthermore, the exchange correlations observed from these spectra yield unambiguous assignments of the unknown or earlier incorrectly assigned 31P chemical shifts for β-P4S6, β-P4S5, α-P4S5, and a new P4S6 isomer (α-P4S6). These assignments are extremely valuable for a correct interpretation of the complex solid-state magic angle spinning (MAS)-NMR spectra of phosphorus sulfides. Two polymorphs for both β-P4S5 and α-P4S6 (the predominant species in the β-P4S5 melt and isolated here for the first time) have been isolated and characterized by high-speed 31P MAS-NMR spectroscopy. Molecular distortions, caused by crystal packing and not easily detected by XRD, are observed for all four polymorphs. These distortions cause nonequivalence between phosphorus atoms which are equivalent for the free molecules. Thereby otherwise unobservable isotropic 1J(P,P)'s have been determined from solid-state NMR spectroscopy.
