Anion-controlled circular dichroism spectral changes in Hg2+ complexes with a chiral bidentate ligand

Mari Ikeda; Shunsuke Kuwahara; Shim Sung Lee; Yoichi Habata

doi:10.1021/ic301140z

Anion-controlled circular dichroism spectral changes in Hg2+ complexes with a chiral bidentate ligand

Inorg Chem. 2012 Jul 2;51(13):7022-4. doi: 10.1021/ic301140z. Epub 2012 Jun 14.

Authors

Mari Ikeda¹, Shunsuke Kuwahara, Shim Sung Lee, Yoichi Habata

Affiliation

¹ Department of Chemistry, Faculty of Science, Toho University, 2-2-1 Miyama, Funabashi, Chiba 274-8510, Japan.

PMID: 22697435
DOI: 10.1021/ic301140z

Abstract

Anion-controlled circular dichroism (CD) spectral changes in Hg(2+) complexes with a chiral bidentate ligand are reported. Although the Hg(CF(3)SO(3))(2) and Hg(CF(3)CO(2))(2) complexes with (R)-(-)-1-(naphthalen-1-yl)-N,N-bis(pyridin-4-ylmethyl)ethanamine, (R)-(-)-1, show significant CD spectral changes, no CD spectral changes were observed in the HgCl(2), HgBr(2), Hg(CN)(2), or Hg(CH(3)CO(2))(2) complexes. X-ray analysis indicates that both the (R)-(-)-1-Hg(CF(3)SO(3))(2) and (R)-(-)-1-HgCl(2) complexes form a coordination polymer and a discrete 2:3 [=(R)-(-)-1/HgCl(2)] complex with a figure-eight structure. X-ray crystallography revealed that (i) the Hg-Hg distances bridged by anions vary depending on the anions used and (ii) a coordination polymer cannot be formed when the Hg-Hg distances are too short. Therefore, the formation of a coordination polymer is required to give the observed significant CD spectral changes.