Arsenates

Structure of the arsenate ion

As arsenates are salts of arsenic acid referred.

The main component of arsenates is the arsenate ion [AsO ₄ ] ³⁻ . Similar to the phosphate ion, this has a tetrahedral structure with an arsenic - oxygen distance of 174 pm. Arsenates are very similar to phosphates in their chemical behavior . As with phosphorus, there are three homologous series of arsenates, the primary (MH ₂ AsO ₄ ), secondary (M ₂ HAsO ₄ ) and tertiary (M ₃ AsO ₄ ) arsenates (M = metal).

Occurrence

Arsenates can be found in a variety of forms as minerals . A distinction must be made between anhydrous and water-containing arsenates. In contrast to the phosphate minerals, the arsenates are secondary to weathering . Examples of arsenate minerals include adamin , annabergite , alarsite , arseniopleit , erythrin , karyinite and legrandite .

In December 2010, GFAJ-1 was reported, a bacterial strain that, according to the study , is said to be able to incorporate arsenate into its biomolecules instead of phosphate . The underlying study was questioned by several bodies after initial considerable media interest and a review in 2012 showed that the thesis must be rejected.

See also

• Systematics of the minerals - class phosphates, arsenates and vanadates

Web links

• Mineral Atlas: Arsenate and Mineral Atlas: Mineral Class VII (Phosphate and Arsenate; Wiki)

Individual evidence

1. ^ AF Holleman , E. Wiberg , N. Wiberg : Textbook of Inorganic Chemistry . 102nd edition. Walter de Gruyter, Berlin 2007, ISBN 978-3-11-017770-1 , p. 845.
2. ↑ Mineralienatlas - mineral class phosphates, arsenates, vanadates .
3. ↑ Felisa Wolfe-Simon, Jodi Switzer Blum, Thomas R. Kulp, Gwyneth W. Gordon, Shelley E. Hoeft, Jennifer Pett-Ridge, John F. Stolz, Samuel M. Webb, Peter K. Weber, Paul CW Davies, Ariel D. Anbar, Ronald S. Oremland: A Bacterium That Can Grow by Using Arsenic Instead of Phosphorus. In: Science . 2010, doi : 10.1126 / science.1197258 .