(CuI) 3 (As 4 Q 4 ) 2 ( Q = S, Se)

The crystal structures of the adduct compounds (CuI)3(As4S4)2 and (CuI)3(As4Se4)2 were determined by single crystal X-ray diffraction analysis. They crystallize isotypically in the space group C2/c (No. 15), Z = 4, with a = 16.529(2) Å, b = 12.404(2) Å, c = 13.324(2) Å, b = 127.28(1)° for (CuI)3(As4S4)2 and a = 16.779(2) Å, b = 12.717(2) Å, c = 13.693(2) Å, b = 127.69(1)° for (CuI)3(As4Se4)2, respectively. Both structures consist of cage-like As4Q4 (Q = S, Se) molecules which are identical to those in a-As4S4 (realgar). The molecules that have almost point group symmetry D2d are embedded in a matrix of copper(I) iodide, see Figure 1. Raman spectra indicate strong interactions between the embedded molecules and the surrounding matrix.