Intrinsically fluorescent glycoligands to study metal selectivity

Inorg Chem. 2011 Nov 21;50(22):11353-62. doi: 10.1021/ic200897v. Epub 2011 Oct 17.

Abstract

Glycoligands are a versatile family of ligands centered on a sugar platform and functionalized by Lewis bases. In this article, pentofuranoses were appended with the fluoroionophores 4-(pyridin-2'-yl)-1,2,3-triazol-1-yl and 4-(2',1',3'-benzothiadiazol-4'-yl)-1,2,3-triazol-1-yl using the "click-like" cycloaddition [2 + 3] of Huisgen catalyzed by copper(I). Their fluorescence properties were used to study metal cation complexation. A possible selective functionalization of furanoscaffolds allows the synthesis of "mixed" glycoligands with the successive insertion of these different fluoroionophores. The metal selectivity and the chelating behavior of these six resulting intrinsically fluorescent glycoligands were investigated. The change in the configuration at the carbon C3 of furanose did not influence either the metal selectivity or the binding constants. However, different selectivities and binding constants were found to depend on the nature of the fluoroionophore moieties. Overall, the triazolylbenzothiadiazolyl chelating group was shown to be less efficient than the triazolylpyridyl claw for complexation. Interestingly enough, the triazolylbenzothiadiazolyl claw, which fluoresces in the visible range, did not interfere in the binding and selectivity of the more efficient triazolylpyridyl claw. This study suggests that the triazolylbenzothiadiazolyl moiety could be used as an adequate fluorescent reporter to qualitatively monitor complexation of other moieties.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Binding Sites
  • Carbohydrates / chemical synthesis
  • Carbohydrates / chemistry*
  • Crystallography, X-Ray
  • Fluorescent Dyes / chemical synthesis
  • Fluorescent Dyes / chemistry*
  • Lewis Bases / chemical synthesis
  • Lewis Bases / chemistry*
  • Ligands
  • Metals / analysis*
  • Models, Molecular
  • Ultraviolet Rays

Substances

  • Carbohydrates
  • Fluorescent Dyes
  • Lewis Bases
  • Ligands
  • Metals