Synthesis, Crystal Structure and Non-linear Optical Properties of [WSe4{Cu(dppm)}4][ClO4]2·MeCN

The reaction of Cu(MeCN)4[ClO4], dppm (bis(diphenylphosphino)methane) and [Et4N]2[WSe4] in DMF-CH2Cl2, affords the cationic cluster [WSe4{Cu(dppm)}4]2+ whose structure was shown by X-ray analysis that four edges of the tetrahedral WSe4 core are bridged by a square arrangement of four Cu(I) atoms with the dppm ligands bridging the edges. The cluster compound exhibits a strong optical limiting effect with threshold of 0.3 J·cm−2.