Counterion and Steric Effects in Self-Assembled HgX₂–Thioether Coordination Polymers

A series of mercury dithioether coordination polymers were synthesized from mercury dihalides and rigid xylyl dithioethers containing methyl, t-butyl, and benzyl pendant groups (ligands 3a–c). The resulting coordination polymers were examined by X-ray crystallography. Changes in sterics surrounding mercury result in structures ranging from one-dimensional polymers (e.g., (3a·HgI2)∞, (3b·Hg2Cl4)∞, (3b·HgBr2)∞) to two-dimensional sheets (e.g., (3c·HgCl2)∞) and three-dimensional extended networks (e.g., [(3c)2(HgBr2)3]∞) from crystallizations which were conducted under identical conditions with the same 1:1 stoichiometry. Bridging mercury–halide bonds were found to play a surprisingly large role in governing the final structures.