No abstract

No abstract

Ketones have been proven effective in extracting astatine­(III) from aqueous solvents. Previous theoretical studies suggested a mechanism where the “sp2” lone pair on the carbonyl oxygen donates electron density into the π system of the AtO+ molecular cation to form a dative-type bond. In this study, co-extraction of NO3 – as AtO­(NO3)·(OCR1R2) species into the organic phase appears to be a key factor. Adjusting the electronic properties of the ketone, by having an aryl group instead of an alkyl group in the alpha position of the ketone, increased the electron density on CO, increased the bond strength between the ketone and AtO+, and in turn increased the extraction of 211At into the organic phase. Extraction with diketones shows dependence on the bridging distance between the two carbonyl moieties, where a C3 or longer bridge results in a 10-fold increase in extraction into the organic phase. DFT calculations show the longer bridge allows for the chelation of AtO­(NO3) by either the second carbonyl or the phenyl ring.

No abstract

Alpha emitting radionuclides with medically relevant half-lives are interesting for treatment of tumors and other diseases because they deposit large amounts of energy close to the location of the radioisotope. Researchers at the Cyclotron Institute at Texas A&M University are developing a program to produce 211At, an alpha emitter with a medically relevant half-life. The properties of 211At make it a great candidate for targeted alpha therapy for cancer due to its short half-life (7.2 h). Astatine-211 has now been produced multiple times and reliability of this process is being improved.