Trialkyl phosphines, oxidation

Apostilidos, C., Meester, R., de Koch, L. et al. 1990. The extraction of actinides and other constituents from highly-active waste (HAW) by trialkyl phosphine oxide (TRPO). Technical seminar on new separation chemistry techniques for radioactive waste and other specific applications, Rome (Italy), May 16-18. EUR-13390-EN. 

Zhu, Y., Jiao, R. 1994. Chinese experience in the removal of actinides from highly active waste by trialkyl phosphine oxide extraction. Nucl. Technol. 108 361-369. 

Feng, X., Song, C. 2001. The extraction and stripping behavior of heptavalent technetium with trialkyl phosphine oxide. Solvent Extr. Ion Exch. 19 (1) 51-60. 

FIGU RE 2.4 Structures of TBP and trialkyl phosphine oxide R, = R2 = R3 = n-octyl TOPO. 

Chinese scientists used trialkyl phosphine oxides (TRPO) to remove long-lived radioactive nuclides from high-level liquid waste (67, 167). TRPO is the trademark of a Chinese commercial product, consisting of a mixture of several TRPO (with alkyl chains from hexyl to octyl). The TRPO process has been tested in China and at ITU in Karlsruhe (2, 168-174). 

The following order of stability can be proposed amide (diglycolamides < malona-mides < monoamides (183, 199, 216)) = CMPO < HDEHP = TBP (10, 42, 77) < tri-alkylphosphonate < trialkyl phosphine oxide (308). 

Jianchen, W., Chongli, S. 2001. Hot test of trialkyl phosphine oxide (TRPO) for removing actinides from highly saline high-level liquid waste (HLLW). Solvent Extr. Ion Exch. 19(2) 231-242. 

The INET annular centrifugal contactors are being used to partition high-level liquid waste so that the back end of the nuclear fuel cycle can be simplified. In particular, the TRPO process has been developed at INET for this application (Song, 2000), where TRPO is the extractant in the process solvent. Also known as Cyanex 923, TRPO is a trialkyl phosphine oxide that is made commercially by Cytec Industries (formerly American Cyanamid). It has a high affinity for the actinides. Further... 

The quaternary phosphonium iodide, R P+I", can be isolated after treatment of the reaction product with aqueous hydrogen sulfide. Thus, white phosphorus heated with excess ethyl iodide at 180° for 22 hr. gave a product from which tetraethylphosphonium iodide was obtained in 49% yield (4). The remainder of the phosphorus was said to be converted to triethylphosphine oxide, although this product was not isolated. When the reaction product is refluxed with ethanol and then distilled over potassium hydroxide, the major product is the trialkyl phosphine oxide (3). Both trialkyldiiodophosphoranes and quaternary phosphonium iodides would be converted to the tertiary phosphine oxide under these conditions. Table III summarizes the... 

Other suitable molecules include trialkyl phosphines and trialkyl phosphine oxides 134-36]. Phosphines bound to Bronsted acid and Lewis acid sites and physisorbed molecules yield distinguishable resonances, although the latter two are poorly resolved from each other. There is no indication of exchange broadening in these cases. 

Trialkyl phosphine Oxides.—These compounds result when the trialkyl phosphines are oxidised directly by atmospheric oxygen, or... 

The trialkyl phosphine oxide can be made from the oxidation of trialkyl phosphine by nitrie acid. ... 

Compounds containing the P=0 group absorb in the region 1300-1140 cm", the exact position depending on the sum of the electronegativities of the substituents. Trialkyl phosphates for example abosrb near 1290 cm , and trialkyl phosphine oxides absorb near 1150 cm Cyclic P—N compounds also absorb in this region. 

Liu, Y., Sun, X., Luo, F., and Chen, J. (2007) The preparation of sol-gel materials doped with ionic liquids and trialkyl phosphine oxides for yttrium(III) uptake. Awat Chim. Acta, 604,107-113. 

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