Magnus' green salt
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Magnus' green salt is the chemical compound with the formula [Pt(NH3)4][PtCl4]. This species has been of interest in materials chemistry and solid state physics because of its one-dimensional structure. It consists of a linear chain of Pt atoms separated by 3.25 Å.[1] The Pt(II) centers are also coordinated to four molecules of ammonia and four chlorides, in an alternating manner. It is a semi-conductor.
[edit] History
The salt was discovered by Heinrich Gustav Magnus in the early 1830's. It was one of the first examples of a metal complex of ammonia. Ammonia species are very common now - they were after all the basis of Alfred Werner's discoveries. MGS has the same empirical formula as cis-PtCl2(NH3)2 ("Peyrone chloride") and trans-PtCl2(NH3)2. These cis and trans compounds are molecules, whereas Magnus' green salt is a polymer.
[edit] Preparation
One mixes aqueous solutions of [Pt(NH3)4]2+ and [PtCl4]2-. A deep green precipitate appears. In recent years, it has been possible to generate soluble polymers by replacing the ammonia with ethylhexylamine.[2][3]
[edit] References
- ^ Atoji, M.; Richardson, J. W.; Rundle, R. E. "On the Crystal Structures of the Magnus Salts, Pt(NH3)4PtCl4" Journal of the American Chemical Society, 1957, volume 79,pp 3017-3020; DOI: 10.1021/ja01569a009
- ^ Caseri, W., "Derivatives of Magnus' green salt; from intractable materials to solution-processed transistors", Platinum Metals Review, 2004, volume 48, pages 91-100.
- ^ Bremi, J.; Caseri, W. and Smith, P., "A new compound derived from Magnus' green salt: solid state structure and evidence for platinum chains in solution", Journal of Materials Chemistry, 2001, volume 11, pages 2593-2596.
