ABSTRACT
Herein, we describe the design and synthesis of an unusual azobenzene-bearing macrocycle 1, whose trans isomer was found able to 100% transform into its cis configuration under photoirradiation, for selectively recognizing HP2O73- with reversibly photo-controllable binding and release properties.
ABSTRACT
Mercury is a highly toxic heavy metal and it poses a serious threat to the natural environment and human health. Thus, selective detection of trace mercury (e.g. inorganic mercury and methylmercury) in the environment is critical yet challenging. Herein, we describe the rational design and facile synthesis of a new triphenylamine-based phenylboronic acid fluorescent probe (TPA-PBA) for selective detection of Hg2+ and CH3Hg+. Due to the inherent specificity of the displacement reaction between phenylboronic acid and mercury, this probe exhibits exceptionally high selectivity towards Hg2+/CH3Hg+ against other tested ions with ppb-level sensitivity. More importantly, the probe TPA-PBA is effective and selective in detecting Hg2+/CH3Hg+ in tap water and real-world groundwater, indicating its potential practical applications in in situ and online mercury detection in real-world scenarios. With TPA-PBA based test strips Hg2+ can be distinguished from CH3Hg+ by the naked eye. This study could accelerate the development of low-cost, highly efficient and selective fluorescent probes for rapid trace mercury detection.
ABSTRACT
A series of new photoresponsive macrocyclic anion receptors were synthesized via integration of an azobenzene unit and multiple anion binding sites. They exhibited highly selective binding to dianionic sulfate over other tested anions and the reversible release of sulfate could be triggered by visible light as inferred from mass spectroscopy, crystallographical analysis, NMR spectroscopy, and theoretical calculations.
ABSTRACT
A new superphane, featuring an aesthetically pleasing structure, was successfully obtained via one-pot synthesis of a hexakis-amine and m-phthalaldehyde in a [2+6] manner. It proved capable of entrapping a water dimer within its cavity as inferred from the mass spectroscopy, crystallographical analysis, NMR spectroscopy, and theoretical calculations.
Subject(s)
Aldehydes/chemical synthesis , Amines/chemical synthesis , Density Functional Theory , Water/chemistry , Aldehydes/chemistry , Amines/chemistry , Capsules , Dimerization , Magnetic Resonance Spectroscopy , Molecular StructureABSTRACT
Calix[4]pyrrole 1 can form host-guest complexes with certain thallium salts, for example, TlF, not only in the gas phase but also in solution and in the solid state. The complexation of TlF by calix[4]pyrrole 1 was found to promote self-assembly and the formation of well-defined and highly ordered fibrous supramolecular morphologies, as revealed by polarizing microscopy and scanning electron microscopy. The findings reported here serve to broaden the scope of cationic substrates that may be complexed as ion pairs by calix[4]pyrrole receptors while setting the stage for the development of new hosts for thallium(I) salts.
ABSTRACT
A number of artificial cation ionophores (or transporters) have been developed for basic research and biomedical applications. However, their mechanisms of action and the putative correlations between changes in intracellular cation concentrations and induced cell death remain poorly understood. Here, we show that three hemispherand-strapped calix[4]pyrrole-based ion-pair receptors act as efficient Na+/K+ exchangers in the presence of Cl- in liposomal models and promote Na+ influx and K+ efflux (Na+/K+ exchange) in cancer cells to induce apoptosis. Mechanistic studies reveal that these cation exchangers induce endoplasmic reticulum (ER) stress in cancer cells by perturbing intracellular cation homeostasis, promote generation of reactive oxygen species, and eventually enhance mitochondria-mediated apoptosis. However, they neither induce osmotic stress nor affect autophagy. This study provides support for the notion that synthetic receptors, which perturb cellular cation homeostasis, may provide new small molecules with potentially useful apoptotic activity.
ABSTRACT
We report what to our knowledge is the smallest bis-calix[4]pyrrole (2). It proved capable of trapping fluoride anions exclusively relative to other anions (Cl-, Br-, SCN-, NO3-, H2PO4-, HSO4-, SO42-, and HP2O73-; tetrabutylammonium salts), as confirmed by 1H NMR spectroscopy (CDCl3), X-ray diffraction analysis, DFT calculations, and molecular dynamics simulations. The F- selectivity is ascribed to the small size of the cavity in 2.
