Reaction of KNH2, K2Se, Se, [2.2.2]-cryptand, and a metal source yields the metal bis(maleonitrilediselenolates) [K([2.2.2]-cryptand)](2)[M(Se2C2(CN)(2))(2)] (M = Ni, 1; Pd, 2, Pt, 3). These compounds are isostructural and crystallize with four formula units in the monoclinic space group P2(1)/c in cells at T = 153 K with parameters (a (Angstrom), b (Angstrom), c (Angstrom), beta (deg), V (Angstrom (3))) Of 12.220(1), 15.860(2), 15.306(1), 107.64(2), 2827(1) for 1; 12.291(1), 15.669(1), 15.548(1), 108.55(1), 2839(1) for 2, and 12.292(3), 15.671(3), 15.569(3), 108.59(3), 2842(1) for 3. The cation of 1 has been substituted to yield [Ni(dmf)(5)Cl](2)[Ni(Se2C(CN)(2))(2)] (4) [Ni(dmf)(5)Cl](2)[Ni(Se2C2(CN)(2))(2)] (4) crystallizes with one molecule in the triclinic space group P (1) over bar in a cell with parameters (T = 153 K) of a = 8.842(2) Angstrom, b = 13.161(3) Angstrom, c = 13.831(3) Angstrom, alpha = 110.08(3)degrees, beta = 95.23(3)degrees, gamma = 93.72(3)degrees, V = 1484(1) Angstrom (3). The electronic absorption and infrared spectra are characteristic of metal maleonitrilediselenolates. Cyclic voltammetry shows that the maleonitrilediselenolate (mns) complexes are more easily oxidized than their maleonitriledithiolate (mnt) analogues.