Synthesis and characterization of the silver maleonitrilediselenolates and silver maleonitriledithiolates [K([2.2.2]-cryptand)]₄[Ag₄ (Se₂C₂(CN)₂)₄], [Na([2.2.2]-cryptand)]₄[Ag₄ (S₂C₂(CN)₂)₄]·0.33MeCN

Reaction of AgBF₄, KNH₂, K₂Se, Se, and [2.2.2]-cryptand in acetonitrile yields [K([2.2.2]-cryptand)]₄[Ag₄ (Se₂C₂(CN)₂)₄] (1). In the unit cell of 1 there are four [K([2.2.2]-cryptand)]⁺ units and a tetrahedral Ag₄ anionic core coordinated in μ₁-Se, μ₂-Se fashion by each of four mns ligands (mns = maleonitrilediselenolate, [Se₂C₂(CN)₂]^2-). Reaction of AgNO₃, Na₂(mnt) (mnt = maleonitriledithiolate, [S₂C₂(CN)₂]^2-), and [2.2.2]-cryptand in acetonitrile yields [Na([2.2.2]-cryptand)]₄[Ag₄ (mnt)₄]·0.33MeCN (2). The Ag₄ anion of 2 is analogous to that in 1. Reaction of AgNO₃, Na₂(mnt), and [NBu₄]Br in acetonitrile yields [NBu₄]₄[Ag₄(mnt)₄] (3). The anion of 3 also comprises an Ag₄ core coordinated by four mnt ligands, but the Ag₄ core is diamond-shaped rather than tetrahedral. Reaction of [K([2.2.2]-cryptand)]₃[Ag(mns)(Se₆)] with KNH₂ and [2.2.2]-cryptand in acetonitrile yields [K([2.2.2]-cryptand)]₃[Ag(mns)₂]·2MeCN (4). The anion of 4 comprises an Ag center coordinated by two mns ligands in a tetrahedral arrangement. Reaction of AgNO₃, 2 equiv of Na₂(mnt), and [2.2.2]-cryptand in acetonitrile yields [Na([2.2.2]-cryptand)]₃[Ag(mnt)₂] (5). The anion of 5 is analogous to that of 4. Electronic absorption and infrared spectra of each complex show behavior characteristic of metal-maleonitriledichalcogenates. Crystal data (153 K): 1, P2/n, Z = 2, a = 18.362(2) Å, b = 16.500(1) Å, c = 19.673(2) Å, β = 94.67(1)°, V = 5941(1) ų; 2, P4̄, Z = 4, a = 27.039(4) Å, c = 15.358(3) Å, V = 11229(3) ų; 3, P2₁/c, Z = 6, a = 15.689(3) Å, b = 51.924(11) Å, c = 17.393(4) Å, β = 93.51(1)°, V = 14142(5) ų; 4, P2₁/c, Z = 4, a = 13.997(1) Å, b = 21.866(2) Å, c = 28.281(2) Å, β = 97.72(1)°, V = 8578(1) ų; 5, P2/n, Z = 2, a = 11.547(2) Å, b = 11.766(2) Å, c = 27.774(6) Å, β = 91.85(3)°, V = 3772(1) ų.