%0 Conference Paper %F Poster %T Degradation Studies of Cyanex 301 %+ Chemical Separations Group [Oak Ridge] (CSG) %+ Idaho National Laboratory, Idaho Falls, ID 83415-2107. %A Marc, Philippe %A Custelcean, Radu %A Klaehn, John, R. %A Peterman, Dean, R. %A Delmau, Lætitia, H. %< avec comité de lecture %B 17th Symposium on Separation Science and Technology for Energy Applications %C Gatlinburg, Tennessee, United States %8 2011-10-23 %D 2011 %K CYANEX 301 %K Degradation %K Nitric acid %K Dithiophosphinic acid %K NMR - Nuclear magnetic resonance %Z Chemical Sciences/Radiochemistry %Z Chemical Sciences/Theoretical and/or physical chemistry %Z Chemical Sciences/Organic chemistryConference poster %X Despite the numerous studies found in the literature on CYANEX® 301, very few explain its degradation in depth. To the best of our knowledge none has explained the inconsistency between the “common knowledge” of “CYANEX® 301 degrades into CYANEX® 272” (dithiophosphinic acid degrading into the corresponding phosphinic acid) and the 31P spectrum obtained by NMR of the degradation compound. The 31P {1H} NMR analysis of a solution of CYANEX® 301 in prolonged contact with nitric acid shows a very complex spectrum, with resonances about 20 ppm downfield from what could have been expected.The degradation product giving those multiple resonances in a pattern that could be interpreted as a triplet of triplet is actually a dimer, where two molecules of CYANEX® 301 are linked by a disulfide bridge, corresponding to the condensation of the SH groups. The explanation of the complexity of the spectrum comes from the comparison with the spectrum obtained for the degradation of a stereoisomerically-purified CYANEX® 301. This purification led to the removal of the [R;S] and [S;R] isomers from the initial mixture, and yielded a white crystalline solid proven to comprise exclusively [R;R] and [S;S] isomers by XRD analysis. It was determined that the carbon chirality induced an asymmetry of the phosphorus atoms upon condensation, leading to a wide combination of magnetically non-equivalent P-31 nuclei, which can also exhibit coupling through the S-S bond The complete explanation of the NMR spectra was established and corroborated by elemental analysis %G English %2 https://cea.hal.science/cea-01267748/document %2 https://cea.hal.science/cea-01267748/file/PMARC%20-%20Poster%20-%20Gatlinburg.pdf %L cea-01267748 %U https://cea.hal.science/cea-01267748 %~ CEA