Two Mercury Chloro Thiocyanate Complexes: NH4[HgCl2(SCN)] and NH4[HgCl(SCN)2]

Single crystals of NH4[HgCl2(SCN)] (1) and NH4[HgCl(SCN)(2)] (2) are obtained by slow evaporation of ethanol solutions of HgCl2 and NH4SCN or Hg(SCN)(2) and NH4Cl. 1 crystallizes in the monoclinic space group P2(1) (a = 9.297(1), b = 4.171(1), c = 9.198(1) Angstrom, beta = 92.827(5)degrees). The structure consists in HgCl2(SCN) linear chains, extending along the twofold axis, connected through the ammonium ions. 2 crystallizes in the monoclinic space group C2/c (a = 7.088(1), b = 19.986(2), c = 5.958(1) Angstrom, beta = 100.718(5)degrees). The structure consists of HgCl(SCN)(2) molecules connected through the ammonium ions. The second order non linear optical properties of 1 are discussed.