Magnus's green salt

This species has attracted interest in materials chemistry and solid-state physics because of its one-dimensional structure. It contains a chain of alternating [PtCl4]2− anions and [Pt(NH3)4]2+ cations, in which the platinum atoms are separated by 3.25 Å. It is a semiconductor. ==Preparation==

The compound may be prepared by combining aqueous solutions of [Pt(NH3)4]2+ and [PtCl4]2−, which gives a deep green solid precipitate. Under some conditions, this reaction affords a pink polymorph of Magnus's green salt. In this so-called "Magnus's pink salt", the square planar Pt complexes are not stacked. ==Related compounds==

Magnus's green salt is one of three compounds with the empirical formula , the others being cisplatin (an important anticancer drug) and transplatin. These cis and trans compounds are molecules, whereas Magnus's green salt is a polymer. This difference is manifested by the solubility of the molecular complexes in water, whereas Magnus's green salt is insoluble. Magnus's green salt occurred as an impurity in early routes to cisplatin from potassium tetrachloroplatinate. Modern production avoids contamination by first converting the tetrachloroplatinate to potassium tetraiodoplatinate, as the iodo ligand's stronger trans effect favors the cis molecule over the polymeric salt. Soluble analogues of Magnus's green salt can be prepared by replacing the ammonia with ethylhexylamine. The corresponding palladium compound ([Pd(NH3)4][PdCl4]) is known as "Vauquelin’s salt". ==History==

Magnus's green salt was one of the first examples of a metal ammine complex. ==References==