Synthesis and Characterization of (Ph4P)2[Ni2As4S8], (Me4N)2[Mo2O2As2S7], and (Et4N)2[Mo2O2As2Se7]. New One-Dimensional Polymeric Compounds Containing Thio- and Selenoarsenate Ligands

The compounds (Ph4P)2[Ni2As4S8] (I), (Me4N)2[Mo2O2As2S7] (II), and (Et4N)2[Mo2O2As2Se7] (III) were synthesized by the hydrothermal reactions of NiCl2/K3AsS3/Ph4PBr, MoO3/K3AsS3/Me4NCl, and MoO3/K3AsSe3/Et4NBr in a 1:3:4, 1:2:4, and 1:4:6 molar ratio, respectively. The (Ph4P)2[Ni2As4S8] (I) crystallizes in the triclinic space group P1̄ (No. 2) with a = 10.613(3) Å, b = 13.230(2) Å, c = 9.617(2) Å, α = 93.53(2)°, β = 96.69(2)°, γ = 71.59(2)°, V = 1272(1) Å3, and Z = 2. The one-dimensional [Ni2As4S8] n 2 n - consists of alternating square planar Ni2+ ions and [As4S8]4- ligands. The (Me4N)2[Mo2O2As2S7] (II) crystallizes in the orthorhombic space group Pbca (No. 61) with a = 18.176(4) Å, b = 17.010(2) Å, c = 16.556(7) Å, V = 5118(4) Å3, and Z = 4. The [Mo2O2As2S7] n 2 n - macroanion possesses a one-dimensional chain-like structure consisting of [Mo2O2S2]2+ cores linked by [As2S5]4- ligands. The (Et4N)2[Mo2O2As2Se7] (III) crystallizes in the orthorhombic space group Cmca No. 64) with a = 15.480(2) Å, b = 18.506(2) Å, c = 22.793(2) Å, V = 6350(1) Å3, and Z = 4. The [Mo2O2As2Se7] n 2 n - is isostructural to the anion in II. The solid state optical spectra of these compounds are reported.