English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Zendy Plus

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Zendy Tools

Zendy Open

A series of hexadentate ditopic receptors incorporating benzimidazole moieties have been designed, which are fitted with phosphonic acid or phosphoethylester coordinating units. In addition, poly(oxyethylene) pendants have been introduced on the benzimidazole backbone of two ligands to increase water solubility. The ligands self-assemble with lanthanide ions under stoichiometric conditions, yielding triple-stranded homobimetallic helicates, as ascertained by mass spectrometry and UV-visible titrations. The helicates display large thermodynamic stability, for example, log beta(23) approximately 21-24 for all the Eu(III) complexes. Photophysical measurements reveal sensitization of the metal-centered luminescence in the europium and terbium complexes, which is modulated by the nature of the ligand. Hydration numbers determined by the lifetime method are essentially zero. The Eu((5)D(0)) lifetimes are long and reach values up to 3.2 ms, while quantum yields as high as 25% are obtained in water at pH 7.4. Back transfer limits the sensitization efficiency for Tb(III) luminescence, and both lifetimes and quantum yields are much smaller. The properties of the helicates are discussed with respect to those self-assembled from ligands bearing carboxylate coordinating units.

Luminescent Lanthanide Helicates Self-Assembled from Ditopic Ligands Bearing Phosphonic Acid or Phosphoester Units