{"id":4943,"date":"2013-03-19T09:45:21","date_gmt":"2013-03-19T09:45:21","guid":{"rendered":"https:\/\/blogs.nature.com\/thescepticalchymist\/?p=4943"},"modified":"2013-03-19T09:45:21","modified_gmt":"2013-03-19T09:45:21","slug":"enigmatic-astatine","status":"publish","type":"post","link":"https:\/\/blogs.nature.com\/thescepticalchymist\/2013\/03\/enigmatic-astatine.html","title":{"rendered":"Enigmatic astatine"},"content":{"rendered":"

When we think of the halogens, F, Cl, Br and I are generally those that spring to mind. Yet there is, of course, another one \u2014 astatine. In contrast to the first four, ubiquitous on earth and which serve in numerous reactions, astatine is rare and has remained a bit of a mystery. It is the topic of this month<\/a>\u2019s \u2018in your element\u2019 article<\/a> (subscription required), written by Scott Wilbur<\/a> from the Department of Radiation Oncology<\/a> at the University of Washington<\/a>.<\/p>\n

As its name reflects \u2014 astatos<\/i> is the Greek word for unstable \u2014 it is radioactive. All of the known isotopes of astatine are radioactive, the longest-lived ones (210<\/sup>At and 211<\/sup>At) with half-lives of only 8.1 and 7.2 h, respectively. This does not facilitate chemical and physical characterization, in particular making it impossible to weigh and even observe element 85 in the conventional sense. Fortunately, these two isotopes can be produced by irradiation of bismuth targets \u2014 only in very small amounts, but sufficient for some research nonetheless.<\/p>\n

The field in which astatine has attracted the most attention is medicine \u2014 but only the 211 isotope; its 210 counterpart is definitely unsuitable as it decays into polonium-210, a species that made the news a few years ago through the poisoning of Alexander Litvinenko<\/a>. Actually, 211<\/sup>At is one of the rare \u03b1-emitters to be investigated for medical applications; they usually wreak havoc in internal organs. I\u2019ll let you go to the article<\/a> to read about its potential medical uses \u2014 as well as the challenges in investigating it, including how difficult it is to even determine whether or not it is released from a carrier molecule.<\/p>\n

In some other ways, astatine behaves very much like other halogens and undergoes electrophilic and nucleophilic reactions. I wouldn\u2019t recommend trading halogens for astatine in any of your up-coming reactions just yet; reproducibility can be an issue (this is not overly surprising considering you may only have about 10-13<\/sup> to a maximum of 10-8<\/sup> grams of astatine in any given sample and this may be a smaller amount than any trace impurities!). In any case, we don’t know nearly enough about astatine’s physical and chemical properties \u2014 but if you like working with minute amounts of decaying species, give it some thought!<\/p>\n

Anne Pichon (Associate Editor, Nature Chemistry<\/i><\/a>)<\/p>\n","protected":false},"excerpt":{"rendered":"

When we think of the halogens, F, Cl, Br and I are generally those that spring to mind. Yet there is, of course, another one \u2014 astatine. In contrast to the first four, ubiquitous on earth and which serve in numerous reactions, astatine is rare and has remained a bit of a mystery. It is the topic of this month\u2019s \u2018in your element\u2019 article (subscription required), written by Scott Wilbur from the Department of Radiation Oncology at the University of Washington.  Read more<\/a> Continue reading →<\/span><\/a><\/p>\n","protected":false},"author":326,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[25,8],"tags":[],"class_list":["post-4943","post","type-post","status-publish","format-standard","hentry","category-anne-pichon","category-in-your-element"],"_links":{"self":[{"href":"https:\/\/blogs.nature.com\/thescepticalchymist\/wp-json\/wp\/v2\/posts\/4943","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/blogs.nature.com\/thescepticalchymist\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/blogs.nature.com\/thescepticalchymist\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/blogs.nature.com\/thescepticalchymist\/wp-json\/wp\/v2\/users\/326"}],"replies":[{"embeddable":true,"href":"https:\/\/blogs.nature.com\/thescepticalchymist\/wp-json\/wp\/v2\/comments?post=4943"}],"version-history":[{"count":0,"href":"https:\/\/blogs.nature.com\/thescepticalchymist\/wp-json\/wp\/v2\/posts\/4943\/revisions"}],"wp:attachment":[{"href":"https:\/\/blogs.nature.com\/thescepticalchymist\/wp-json\/wp\/v2\/media?parent=4943"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/blogs.nature.com\/thescepticalchymist\/wp-json\/wp\/v2\/categories?post=4943"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/blogs.nature.com\/thescepticalchymist\/wp-json\/wp\/v2\/tags?post=4943"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}