Highly emissive polymorphs of anhydrous cadmium tetracyanoplatinate and their solvated coordination networks.

Two anhydrous polymorphs of cadmium cyanoplatinate Cd[Pt(CN) 4 ] coordination polymers have been synthesized and thermally, spectroscopically, and structurally characterized. α-Cd[Pt(CN) 4 ] and β-Cd[Pt(CN) 4 ] are densely packed, highly emissive 3-D solids, with quantum yields of 0.85 ( λ em = 520 nm) and 0.79 ( λ em = 448 nm) respectively. Their mutual hydrate, Cd(H 2 O)[Pt(CN) 4 ]·2H 2 O, forms a complex 3-D coordination polymer with Cd-O-Cd bridges and Pt-Pt interactions. Additionally, exposure of solid α-Cd[Pt(CN) 4 ] and β-Cd[Pt(CN) 4 ] to several solvent vapours results in the formation of 2-D cyanometallate sheets of the adduct compounds CdL 2 [Pt(CN) 4 ] (L = DMSO, DMF, and pyridine). Cd(pyridine) 2 [Pt(CN) 4 ] shows a significantly lower quantum yield (0.32) in comparison to the parent Cd[Pt(CN) 4 ] coordination polymers. Upon heating CdL 2 [Pt(CN) 4 ] preferentially forms the kinetic product α-Cd[Pt(CN) 4 ].