Designing light-switchable heteroditopic receptors is challenging because it necessitates simultaneous (de)activation of two separate binding sites. Herein, we present the first photoswitchable heteroditopic ionpair receptor in which both cation and anion binding sites are simultaneously and reversibly switched OFF and ON by a single photoswitch. Our receptor is simple, low molecular weight, and readily synthesized from commercially available precursors. Single-crystal X-ray structures and NMR spectroscopic titrations support ion-pair binding to the receptor both in the solid state and in solution, with strong positive cooperativity between the cation and anion binding. The receptor can be completely switched OFF by UV light-triggered photoisomerization of an acylhydrazone CN double bond and remains kinetically stable in the deactivated form due to an intramolecular hydrogen bond. Its re-activation could be achieved by light irradiation or, more effectively, by fast acid-catalyzed back-isomerization. Our simple photoswitchable ion-pair receptor may serve as a blueprint for the design of new generations of switchable receptors, transporters, soft materials, and self-assembled systems, where incorporation of a functional heteroditopic ON/ OFF photoswitch has been challenging up to now.

A set of (p-cymene)-ruthenium amino acid bioconjugates 1 and 2 is reported.The bioconjugates 2 show micromolar affinity for proteins.Increased potency and selectivity of 2 towards cancer cell lines is detected.The cytotoxicity of bioconjugates 2 is in correlation with their BSA binding constants.Cell stress response includes increase of cells in S phase of cell cycle, induction of autophagy and use of GSH as detoxification mechanism.

A non-covalent self-assembled chiral alanyl aminopyridine ligand exhibits supramolecular chirality in solution, independent of the organic solvent used. The supramolecular chirality of the assemblies is completely inverted by complexation to zinc ions. To date, such a supramolecular metal-ligand system has not been reported in the literature.

Bioconjugate bidentate ligands 2−10 were obtained by tethering triphenylphosphanecarboxylic acid to amino acid substituted spacers with different flexibility, ranging from a rigid enediyne-based β-turn inducer to flexible linear aliphatic chains with up to eight carbon atoms. The 21 synthesized ligands revealed up to 81% ee selectivity in rhodium-catalyzed asymmetric hydrogenation of α,β-unsaturated amino acids. The key feature of the catalysts is the prochiral coordination sphere of the catalytic metal while the chirality is transmitted by "backdoor induction" from distant hydrogen-bonded amino acids. DFT calculations were applied to study the structure and relative stability of the precatalytic organometallic Rh(I) complexes, with particular emphasis on hydrogen-bonded secondary structures.