The synthesis and crystal structure of the salt (TTF)(HgCl3) are reported. Crystals of the salt are triclinic, of space group PI, with a = 12.661 (3) k, b= 15.969 (4) Å, c = 7.416 (2) Å, α = 98.69 (2)°, β = 95.73 (2)°, γ = 120.01 (2)°, V = 1256.2 A3, mol wt ((C6H4S4)(HgCl3)) = 511.3, Z = 4, Dmeasd = 2.68 (1) g cm-3, and = 2.70 g cm-3. The structure was solved by standard Patterson and Fourier methods and has been refined by full-matrix least squares, based on 4298 counter-collected F0's, to a final R value of 0.080. The structure can be qualitatively separated into two layers parallel to the ac plane. One of these layers, centered about y = 0.0, contains both inorganic and organic polymers propagating along the crystallographic c axis. The covalent inorganic polymer contains roughly trigonal-bipyramidal coordination about the Hg(II) center, with equatorial Hg-Cl bond lengths of 2.374 (5), 2.395 (5), and 2.545 (5) Å and considerably longer axial bond lengths of 2.982 (5) and 3.112 (5) Å. Collinear with this covalent inorganic polymer is a columnar array of stacked TTF radical cations. The stacking in this columnar array of TTF cations is nominally of the ring-over-bond type with a mean separation between planes of 3.6 Å. The second layer, centered about y = 0.5, contains solely dimeric species. The chloromercurate anion is a dimeric, edge-shared bitetrahedron, with Hg-Cl bond lengths of 2.600 (5) and 2.696 (5) Å for the bridging chloro ligands and 2.368 (5) and 2.381 (5) Å for the two independent terminal chloro ligands. The organic dimer is made up of two strongly associated and nearly eclipsed TTF cations, with a mean spacing of 3.43 Å. Resonance Raman data have been interpreted as suggesting the presence of two different kinds of TTF moieties, consistent with the X-ray data. From the Raman data it is indicated that the two different TTF species have slightly different degrees of charge transfer.
ASJC Scopus subject areas
- Physical and Theoretical Chemistry
- Inorganic Chemistry