Solid state gold-platinum complexes

The complex was non-luminescent at room temperature, but it displayed luminescence in the solid state at 77 K, showing an unstructured emission at 443 nm. This emission was attributed to the gold centers or to the interaction between the gold and platinum ions. In fact, the isostructural [(NH3)4Pt][Ag(CN)2]1.4(H20) was not luminescent and, similarly, the corresponding [Ni(NH3)2][Au(CN)2]2, whose structure only showed gold-gold interactions (3.0830(5) A), did not display luminescence at either room temperature or at 77 K. 

A variety of halide and haloamine complexes have been prepared which show evidence for one-dimensional structures in the solid state. The materials can be broken down into (1) complexes containing metals in the same oxidation state and (2) complexes comprised of metals in different oxidation states. Type (1) complexes may be dianions and dications, for example Magnus Green Salts or alternatively chains of neutral molecules, for example, Pt(en)Cl2. Type (2) complexes are comprised of alternating square planar rf metal complexes (metal = Pdii,Pt ,Aui i) and octahedral / metal complexes (metal = Pd, Pt ), or linear platinum complexes are formally trivalent while the gold complexes are formally divalent. 

The electrochemical reduction of Bi - in AlClg-NaCl melts (52-63 mole % AICI3) has been studied by voltammetry, linear sweep voltammetry, and chronopotentiometry at solid electrodes. Torsi and Mamantov found that Bi + is reduced reversibly to Bi" further reduction of Bi+ to Bi is complex and involves intermediate oxidation states which were not characterized electrochemically. Strong adsorption of Bi " at gold and platinum electrodes was observed. As in other systems,the lower oxidation states were found to be more stable at lower temperatures and in more acidic melts. 

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