Synthetic water soluble di-/tritopic molecular receptors exhibiting Ca/Mg exchange.

Structural integration of two synthetic water soluble receptors for Ca and Mg, namely 1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid (BAPTA) and o-aminophenol-N,N,O-triacetic acid (APTRA), respectively, gave novel di- and tritopic ionophores (1 and 2). As Mg and Ca cannot be simultaneously complexed by the receptors, allosteric control of complexation results. Potentiometric measurements established stepwise protonation constants and showed high affinity for Ca (log K = 6.

A ratiometric luminescent oxygen sensor based on a chemically functionalized quantum dot.

Nanoconjugates composed of CdSe-ZnS core-shell nanocrystals and pyrenyl ligands are shown to exhibit a double photoluminescence. Owing to the different response of the two emission signals towards oxygen, the nanocrystals function as high dynamic range ratiometric luminescent O(2) nanosensors.

Reversible electronic energy transfer: a means to govern excited-state properties of supramolecular systems.

A strategy to manage energy, following light absorption, and modulate excited-state properties, including luminescence lifetimes of multicomponent photoactive systems, is presented. The intervening mechanism, which is illustrated through the use of bi-/multi-chromophoric molecules, relies on energy shuttling between different matched chromophores under kinetic and thermodynamic control. This tutorial review is destined to show supramolecular and materials chemists, spectroscopists and nanoscientists how to harness reversible electronic energy transfer in a predictable fashion in designer molecule-based systems.