X-ray photoemission spectroscopy has been used to examine how Hg is bound to a polymer-bound thiacrown shown to be effective in extracting Hg-II from acidic aqueous solutions. High resolution Hg 4f and S 2p core-level spectra were acquired for a set of well-characterized sulfur-containing model compounds and their corresponding Hg complexes. Results from these materials were used to interpret the Hg 4f and S 2p core-level spectra of the polymer-bound thiacrown material, the thiacrown monomeric precursors and the Hg-containing reacted polymer. The thiacrown structure was found to be unaffected by incorporation into the polymer and Hg appears to be bound to the polymer complex in a similar manner as tig is bound in monomeric thiacrowns containing five sulfur atoms.