Structural diversity in mercury(II) bis (O-alkyldithiocarbonate) compounds

Abstract

Abstract The crystal and molecular structures of four compounds of the general formula Hg(S2COR)2 are reported. The colorless crystals of [Hg(S2CO n Bu)2] are orthorhombic, space group Pbcn with unit cell dimensions a = 7.418(5) Å, b = 25.66(5) Å, c = 8.61(3) Å, Z = 4 and D x = 2.022Mg m−3. The colorless crystals of [Hg(S2COCH2CH2C(H)Me2)2] are monoclinic, space group Cc with unit cell dimensions a = 28.72(2) Å, b = 5.828(9) Å, c = 11.41(2) Å, β = 99.7(1)°, Z = 4 and D x = 1.859 Mg m−3. Crystals of pale-yellow [Hg(S2COCH2CH2CMe3)2] are monoclinic, space group P21/c with unit cell dimensions a = 30.045(4) Å, b = 5.955(8) Å, c = 11.712(2) Å, β = 97.07(2)°, Z = 4 and D x = 1.773 Mg m−3. The pale-yellow crystals of [Hg(S2COnPent)2] are monoclinic, space group Cc with unit cell dimensions a = 27.32(1) Å, b = 5.854(7) Å, c = 11.384(7) Å, β = 95.35(5)°, Z = 4 and D x = 1.931 Mg m−3. The structures were solved by direct methods and each refined by a full-matrix least-squares procedure to final R = 0.064 using 908 reflections for [Hg(S2COnBu)2]; to R = 0.054 using 1336 reflections for [Hg(S2COCH2CH2C(H)Me2)2]; to R = 0.041 for 2365 reflections for [Hg(S2COCH2CH2CMe3)2]; and to R = 0.029 for 1094 reflections for [Hg(S2COnPent)2]. The new structures reported herein feature interconnected 16-membered rings that arise as a result of bidentate bridging xanthate ligands. The overall structure in each case is best described as being comprised of layers separated by hydrophobic interactions. A qualitative model, based on the requirements of crystal packing, is proposed to explain the appearance of the three distinct structural motifs for the Hg(S2COR)2 compounds.