Facile syntheses and structures of new metal-maleonitrilediselenolates [K([2.2.2]-cryptand)]3[Ag(Se2C2(CN)2)(Se6)], [K([2.2.2]-cryptand)]2[Ni(Se2C2(CN)2)2], and Ni(dppp)(Se2C2(CN)2)

Facile syntheses of [K([2.2.2]-cryptand)(3)Ag(Se2C2(CN)(2))(Se-6)] (1) and [K([2.2.2]-cryptand)](2)-[Ni(Se2C2(CN)(2))(2)] (2) are achieved through reaction of polyselenides with KNH2, [2.2.2]-cryptand, and AgBF4 or Ni(dppp)Cl-2 in acetonitrile. The syntheses of 2 and Ni(dppp)(Se2C2(CN)(2)) (3) may be achieved by reaction of 1 with NiCl2 or Ni(dppp)Cl-2 in dmf. These compounds represent the first easily prepared metal-maleonitrilediselenolate derivatives.