Unstable allotropes stored safely in carbon

Abstract

Although the elemental allotropes white phosphorus (P4) and yellow arsenic (As4) have the potential to be useful reagents, these compounds aren’t commonly used by chemists because of their notorious instability. White phosphorus will burst into flame when exposed to air and is subject to strict shipping regulations. Light-sensitive yellow arsenic turns to gray arsenic so quickly that solutions of the element must be used in complete darkness. Chemists have been working to create materials in which these allotropes can be stored stably, but their success has been limited. Now, University of Regensburg’s Manfred Scheer and colleagues have found that the pores within activated carbon work well at storing both white phosphorus and yellow arsenic. What’s more, the elements can be released from the activated carbon into solution, where they can subsequently be used as reagents (Nat. Commun. 2018, DOI: 10.1038/s41467-017-02735-2). Scheer’s group prepares the material by adsorbing a solution of