X-ray absorption spectroscopy of thiacrown compounds used in the remediation of mercury contaminated water

Effective methods for the removal of mercury from water are in demand due to the high levels of mercury released from industrial and natural processes. Polymer pendant thiacrown compounds used for the sequestration of Hg(II) from aqueous solutions have shown great promise as effective tools for remediation. Three thiacrowns that have been used for mercury chelation, [18]aneS(6) and [17]aneS(5)-polymer (with divinylbenzene) at two Hg(II) loadings, were examined by X-ray absorption spectroscopy in an attempt to determine the bonding configuration between the sulfurs of the thiacrown and the mercury. For Hg[18]aneS(6), it was found that four of the possible six crown sulfur atoms were involved in mercury bonding. For the Hg[17]aneS(5)-polymer, it was found that three of the possible five crown sulfur atoms were involved in mercury bonding. These thiacrown components appear to form stable mercury complexes and should be effective agents for sequestering and potential recycling of mercury from water. (C) 2002 Elsevier Science B.V. All rights reserved.