Implications for mercury toxicity from the structure of an Oxacalix[3]arene-HgCl2 complex?

t-Butyloxacalix[3]arenetris(diethylacetamide), known to mimic the cellular sodium ion selectivity filter, has been shown to bind HgCl2. The dimeric complex crystallises in the triclinic space group P1 with a=17.3019(6) Å, b=18.7821(4) Å, c=19.9025(5) Å, !=67.3010(10)°, #=77.664(2)°; %=77.238(2)° and Dc=1.370 g cmm3 for Z=4. Refinement based on 37,818 observed reflections gave a final R value of 0.0483. Implications for routes of mercury uptake are discussed.