(HgBr 2 ) 3 (As 4 S 4 ) 2 : An Adduct of HgBr 2 Molecules and Undistorted As 4 S 4 Cages

(HgBr 2 ) 3 (As 4 S 4 ) 2 is obtained by high temperature reaction of stoichiometric amounts of HgBr 2 and As 4 S 4 . It crystallizes in the monoclinic space group P 2 1 / c with the lattice constants a = 9.593(5) Å, b = 11.395(5) Å, c = 13.402(5) Å, β = 107.27(3)°, V = 1399(1) Å 3 , and Z = 2. The crystal structure consists of molecular units built from two undistorted As 4 S 4 cages which are coordinated weakly by three almost linear HgBr 2 units. Raman spectra clearly indicate minor bonding interactions between HgBr 2 and As 4 S 4 .