•A novel probe VC comprising coumarin as a fluorophore and a vinyl ether group as recognition unit is synthesized by optimizing the elimination reaction condition.•Probe VC treated with Hg2+ in HEPES buffer solution shows remarkable fluorescence enhancement.•Probe VC displays a high selectivity and sensitivity toward Hg2+ in neat aqueous solution, which is applied to detect Hg2+ in real water sample.A new probe VC comprising coumarin as a fluorophore and a vinyl ether group as recognition unit is designed and synthesized. The key synthetic step is investigated by elimination reaction using 7-bromoethaneoxy-4-methylcoumarin with different bases. The probe VC shows almost no fluorescence in HEPES buffer (20 mM, pH 7.0), while displays obvious fluorescence enhancement after addition of Hg2+. Recognition mechanism is studied by NMR titration and MS, suggesting that the strongly fluorescent appearance is attributed to 7-hydroxy-4-methylcoumarin, the Hg2+-promoted hydrolysis reaction product. Due to the irreversible reaction and coumarin fluorescence property, the probe VC exhibits remarkable selectivity and sensitivity toward Hg2+ (the detection limit is 0.12 μM). In addition, the detection experiment in real water sample reveals that probe VC could be used as a convenient tool to monitor Hg2+ in neat aqueous solution by fluorescence turn-on response.

•We report a new quinoline-based colorimetric chemosensor CQ for Cu2+ with high selectivity and sensitivity.•Test strips immersed sensor CQ can be used to conveniently monitor Cu2+ by naked-eyes.•Sensor CQ treated with Cu2+ can be applied to sequentialy detect cyanide anion.A new quinoline-based chemosensor (CQ) for sequential detection of Cu2+ and CN− has been synthesized, where diaminomaleonitrile is introduced as recognition group. After addition of Cu2+, sensor CQ in aqueous solution (DMSO/H2O) displays remarkable colorimetric change from the light yellow to red, which is attributed to the extended intermolecular charge transfer in CQ-Cu2+complex. Sensor CQ shows a highly selective and sensitive response to Cu2+, which can be used as Test strips to conveniently monitor Cu2+. In addition, CQ-Cu2+complex could be applied to monitor sequentially cyanide anion with dramatic colour change based on copper ion complex displacement mechanism.Download high-res image (215KB)Download full-size image

•The probe shows not any absorption peaks in visible and near-infrared region in the absence of Pb(II) ions.•Near-infrared fluorescent probe shows no fluorescence in the absence of Pb(II) ion.•The probe shows significant absorption peak at 718 nm in the presence of Pb(II) ions.•The probe shows highly fluorescence at 735 nm in the presence of Pb(II) ions.•The probe responds to Pb(II) reversibly in absorption and fluorescence changes.•The probe can detect Pb(II) in living cells.A new near-infrared fluorescent probe (NIR-PbP) for sensitive detection of Pb(II) ions in solution and living cells has been rationally designed and synthesized. The NIR-PbP is inherently non-fluorescent and gains fluorescence in the presence Pb(II) ions. The ion detection is based on Pb(II)-induced unmasking the fluorophore through the opening of the spyrocycle, with more than 500-fold fluorescence enhancement for sub-micromolar Pb(II) concentration. The NIR-PbP has high sensitivity, good photo-stability, low detection limit, and reversible response to Pb(II) ions.Download high-res image (100KB)Download full-size image

Acene derivatives as a class of polycyclic aromatic hydrocarbons have attracted considerable interest because of their outstanding semiconductor properties. We developed a one-pot synthesis for fully conjugated tetraphene via a sequence of propargyl-allenyl isomerization, phosphine addition, intramolecular Wittig reactions, and Diels–Alder cyclization reactions. The derivative-conjugated aromatic compounds including carbazole or triphenylamine have been constructed via Pd-catalyzed coupling reaction with dibromotetraphene. These compounds show superior photophysical and electrochemical properties, which make them possible candidates for optoelectronic conjugated materials.

Three 2-cyano boron-dipyrromethene (BODIPY) based derivatives (CB1–CB3) have been synthesized and characterized. The photophysical properties of these compounds are investigated by means of UV/Vis absorption and fluorescence spectroscopy. CB1–CB3 exhibit small Stokes shift and high fluorescence quantum yield. Noticeably, CB2 with styrene moieties at 5-position of BODIPY displays absorption alternation with maximum of 120 nm red-shift upon addition of DBU (1,8-diazabicyclo[5.4.0]undec-7-ene) as a base, giving remarkable color change which can be detected by naked eye. Meanwhile, the compound CB3 shows high selectivity toward fluoride ion via fluorescence quenching mechanism by release of the masked phenolate form of CB2 through fluoride ion induced deprotection reaction. It also exhibits fast signal response time (30 s) and excellent selectivity over other competing analytes, making it a good candidate as colorimetric sensor for fluoride sensing.