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 center dot HgI2)(infinity),(3b center dot Hg2Cl4)(infinity,) (3b center dot HgBr2)(infinity)) to two-dimensional sheets (e.g., (3c center dot HgCl2)(infinity)) and three-dimensional extended networks (e.g., [(3c)(2)(HgBr2)(3)](infinity)) 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.