Syntheses and Characterization of the Metal Maleonitrilediselenolates [K([2.2.2]-cryptand)]2[M(Se2C2(CN)2)2] (M = Ni, Pd, Pt) and [Ni(dmf)5Cl]2[Ni(Se2C2(CN)2)2]

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 P21/c in cells at T = 153 K with parameters (a (Å), b (Å), c (Å), β (deg), V3)) 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)5Cl]2[Ni(Se2C2(CN)2)2] (4). [Ni(dmf)5Cl]2[Ni(Se2C2(CN)2)2] (4) crystallizes with one molecule in the triclinic space group P1̄ in a cell with parameters (T = 153 K) of a = 8.842(2) Å, b = 13.161(3) Å, c = 13.831(3) Å, α = 110.08(3)°, β = 95.23(3)°, γ = 93.72(3)°, V = 1484(1) Å3. 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.