Syntheses of bis(organomercury)1,3-dithiole-2-thione-4,5-dithiolates and related compounds: Crystal structure of bis(phenylmercury)1,3-dithiole-2-one-4,5-dithiolate

Abstract

The syntheses, IR and UV spectra and thermal analysis are reported of the organomercury 1,2-dithiolates, bis-(organomercury)1,3-dithiole-2-thione-4,5-dithiolates [(RHg)2(dmit)], 1,3-dithiole-2-one-4,5-dithiolates [(RHg)2(dmio)], and 1,2-dithiole-3-thione-4,5-dithiolates [(RHg)2(dmt)], (R=Me or Ph). As shown by TGA, the onset of thermal decomposition occurs in all cases below 160°C: in each case, thermal decomposition occurs in various stages with loss of R2Hg. A single crystal structure determination of [(PhHg)2(dmio)] revealed the presence of centrosymmetric dimeric units, which are linked via S⋯S, π⋯π and Hg⋯π into a layered structure. Within the dimer, there are two distinct “T” shaped Hg(II) environments: Hg1 is asymmetrically chelated to the dmio ligand with bond lengths Hg1–S1 and Hg1–S2=2.3813(13) and 2.9315(12)Å, and with a chelate bite angle of 84.17(4)° and a near linear S1–Hg1–C11 bond angle of 172.30(13)°. Atom, Hg2, is bonded to a single thiolato atom, S2, of one dmio ligand [Hg2–S2=2.3853(12)Å] and to the carbonyl oxygen of the other dmio unit in the dimer: [Hg2–O1=2.738(4)Å], with bond angles 171.23(16)°, 97.53(9)° and 91.05(17)°, respectively for S2–Hg2–C21, S2–Hg2–O1 and C21–Hg2–O1. All the compounds appear polymeric and are poorly soluble in organic solvents.