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

The crystal and molecular structures of four compounds of the general formu la Hg(S2COR)(2) are reported. The colorless crystals of [Hg(S(2)COnBu)(2)] are orthorhombic, space group Pbcn with unit cell dimensions a = 7.418(5) A ngstrom, b = 25.66(5) Angstrom, c = 8.61(3) Angstrom, Z = 4 and D-x = 2.022 Mg m(-3). The colorless crystals of [Hg(S2COCH2CH2C(H)Me-2)(2)] are monocl inic, space group Cc with unit cell dimensions a = 28.72(2) Angstrom, b = 5 .828(9) Angstrom, c = 11.41(2) Angstrom, beta = 99.7(1)degrees, Z = 4 and D -x = 1.859 Mg m(-3). Crystals of pale-yellow [Hg(S2COCH2CH2CMe3)(2)] are mo noclinic, space group P2(1)/c with unit cell dimensions a = 30.045(4) Angst rom, b = 5.955(8) Angstrom, c = 11.712(2) Angstrom, beta = 97.07(2)degrees, Z = 4 and D-x = 1.773 Mg m(-3). The pale-yellow crystals of [Hg(S(2)COnPen t)(2)] are monoclinic, space group Cc with unit cell dimensions a = 27.32(1 ) Angstrom, b = 5.854(7) Angstrom, c = 11.384(7) Angstrom, beta = 95.35(5)d egrees, Z = 4 and D-x = 1.931 Mg m(-3). The structures were solved by direc t methods and each refined by a full-matrix least-squares procedure to fina l R = 0.064 using 908 reflections for [Hg(S(2)COnBu)(2)] to R = 0.054 using 1336 reflections for [Hg(S2COCH2CH2C(H)Me-2)(2)]; to R = 0.041 for 2365 re flections for [Hg(S2COCH2CH2CMe3)(2)]; and to R = 0.029 for 1094 reflection s for [Hg(S(2)COnPent)(2)]. The new structures reported herein feature inte rconnected 16-membered rings that: arise as a result of bidentate bridging xanthate ligands. The overall structure in each case is best described as b eing comprised of layers separated by hydrophobic interactions. A qualitati ve model, based on the requirements of crystal packing, is proposed to expl ain the appearance of the three distinct structural motifs for the Hg(S2COR )(2) compounds.