Turn-on fluorescence of ruthenium pyrene complexes in response to bovine serum albumin

Two novel pyrene triphenylphosphine ruthenium conjugates act as fluorescent turn-on beacons for serum albumin, being non-fluorescent in aqueous media but exhibiting strong emission upon binding to BSA. The selective cytotoxicity of the compounds against tumour cells is enhanced upon irradiation by UV-light, paving the way for application in photodynamic therapy under two-photon excitation.

Tandem amide coupling and hydroamination: unexpected benzotriazole oxide addition to the propiolic acid triple bond

An unexpected tandem reaction consisting of amide coupling and hydroamination occurring with common triazole coupling reagents.

Induction of Λ-helicity in a zinc complex with an alanine-appended aminopyridine ligand

The crystal structure of tris[dimethyl 5-({1-[(pyridin-2-yl-κN)carbamoyl-κO]ethyl}carbamoyl)benzene-1,3-dicarboxylate]zinc(II) dinitrate acetonitrile trisolvate, [Zn(C₁₉H₁₉N₃O₆)₃](NO₃)₂·3CH₃CN or [Zn(L)₃](NO₃)₂·3CH₃CN, (1), has been determined by single-crystal X-ray diffraction. The neutral ligand L coordinates to the Zn²⁺ cation in a bidentate fashion via the pyridine N atom and an amide O atom, forming a six-membered chelate ring. The Λ-helical chirality of the Zn²⁺ coordination sphere is induced by pendant L-alanine residues through stacking interactions between the arene groups of two coordinated ligands, assisted by a hydrogen bond between amide groups bonded to the stacked arene rings. The third ligand is coordinated to the Zn²⁺ cation by the same six-membered chelate ring, but in the opposite direction with respect to the analogous chelate rings of the first two coordinated ligands. Besides ionic interactions between [ZnL₃]²⁺ complexes and NO₃^- anions, several types of hydrogen bonds and intermolecular stacking interactions contribute to the stability of the solid-state phase.