Samarium (II) Iodide Lambert M Surhone

Publisher Marketing: Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. Samarium(II) iodide (SmI2) is a green solid composed of samarium and iodine, with a melting point of 520 C where the samarium atom has a coordination number of seven in a capped octahedral configuration. It can be formed by high temperature decomposition of SmI3 (the more stable iodide), but a convenient lab preparation is to react Sm powder with 1,2-diiodoethane in anhydrous THF, or CH2I2 may also be used. Samarium(II) iodide is a powerful reducing agent - for example it rapidly reduces water to hydrogen. It is available commercially as a dark blue 0.1 M solution in THF. Esters react similarly (adding two R groups), but aldehydes give by-products. The reaction is convenient in that it is often very rapid (5 minutes or less in the cold). Although samarium(II) iodide is considered a powerful single-electron reducing agent, it does display remarkable chemoselectivity among functional groups. For example, sulfones and sulfoxides can be reduced to the corresponding sulfide in the presence of a variety of carbonyl-containing functionalities (such as esters, ketones, amides, aldehydes, etc).