Luminescence properties of three structures built from 3-cyano-4-dicyanomethylene-5-oxo-4,5-dihydro-1H-pyrrol-2-olate and alkaline metals (Na, K and Rb).

The structures of three salts of 3-cyano-4-dicyanomethylene-5-oxo-4,5-dihydro-1H-pyrrol-2-olate with alkali metals (Na, K and Rb) are related to their luminescence properties. The Rb salt, rubidium(I) 3-cyano-4-dicyanomethylene-5-oxo-4,5-dihydro-1H-pyrrol-2-olate, Rb(+).C(8)HN(4)O(2)(-), is isomorphous with the previously reported potassium salt.