Reactive Fluorescent and Colorimetric Probe for Highly Selective and Sensitive Detection of Hg in Real Water Samples.

Construction of efficient chemosensors for highly specific and sensitive detection of mercury ions remains a great challenge. In this work a highly selective and sensitive probe CY was designed and synthesized by using coumarin fluorophore as the matrix and thioacetal moiety as the reactive recognition site for Hg. By virtue of the thiophilicity of Hg, probe CL could be hydrolyzed to deprotect and the thioacetal was transformed to the acyl group after the addition of Hg, the blue-green fluorescence was quenched and meanwhile the solution changed from light green to yellow.

Multifunctional near-infrared fluorescent probe for sensing of lysine and Cu/Fe and relay detection of biothiols.

Lysine (Lys), Cu and Fe ions and biothiols are essential to a myriad of biological and pathological pathways, and their dysregulation is implicated in a variety of diseases. Development of fluorescent probes capable of detecting multiple analytes may be of great significance for early and accurate diagnosis of diseases and remains a huge challenge. In this context, a novel coumarin-dicyanoisophorone-based probe, engineered for the concurrent sensing of Lys, Cu, Fe and biothiols was developed.

Near-infrared fluorescent probe with large Stokes shift for specific detection of lysine.

A new near-infrared (NIR) fluorescent probe CL based on coumarin- dicyanoisophorone was synthesized. Addition of Lys to probe CL solution in DMF/HO (9:1, v/v) medium resulted in noticeable enhancement in the intensity of the fluorescence emission at 702 nm, accompanying distinct color change from yellow to pink. While addition of other amino acids and biothiols (Gly, Hcy, GSH, Glu, Val, Tyr, Arg, Trp, Lys, His, Leu, Phe, Asp and Met) did not bring about substantial changes in both fluorescence emission and color.

Selective and Sensitive Detection of Hg and Ag by a Fluorescent and Colorimetric Probe with Large Stokes Shift.

Development of fluorescent sensors with large Stokes shift for selective detection of heavy metals is of great importance. A novel fluorescent probe with extremely large Stokes shift (212 nm) was synthesized for selective and simultaneous detection of Hg and Ag ions. The deep yellow probe turned colorless or pale yellow after addition of Hg or Ag.

Highly selective and sensitive detection of Hg by a novel fluorescent probe with dual recognition sites.

A novel thionocarbonate-coumarin-thiourea triad-based probe with dual recognition sites for sensing mercury (Hg) ion was developed. The synthesized probe possessed both fluorogenic ("off-on") and chromogenic (from colorless to blackish brown) sensing performance towards Hg ions. The fluorescence intensity was increased by 70 fold after the addition of Hg.

A New Spiropyran-Based Fluorescent Probe for Dual Sensing of Ferrous Ion and pH.

A new spiropyran-based fluorescent probe was developed for dual detection of Fe ion and pH. Addition of Fe and Ag to the probe solution enhanced the fluorescence intensity by 6 and 5 fold, respectively. Addition of Fe, Hg and Ni caused slight increase in the fluorescence intensity of the probe.

Ultrasensitive and selective fluorescent sensor for cysteine and application to drug analysis and bioimaging.

A fluorescent sensor based on coumarin-maleimide conjugate was developed for efficient discrimination of Cys from Hcy and GSH in both organic and aqueous solution. Addition of Cys to the non-fluorescent sensor solution in DMF induced bright blue fluorescence and enhanced the fluorescence intensity by 320-fold while other amino acids and biothiols (Gly, Hcy, GSH, Glu, Val, Tyr, Arg, Trp, Lys, His, Leu, Phe, Asp and Met) did not bring about remarked change. The sensor responds to Cys extremely rapidly.

[Regional Air Pollution Process in Winter over the Yangtze River Delta and Its Influence on Typical Northern Cities].

In this study, we analyzed several pollution episodes that occurred in the autumn and winter of 2018-2019 using multiple methods including the hierarchical clustering analysis, backward trajectory, and potential source contribution analysis based on monitored air quality and meteorological data. Bengbu, being a representative city to the north of the Yangtze River Delta (YRD) region and located in a heavily polluted area during these two pollution processes, is the focus of this work. The results indicated that the northern part of the YRD region is affected because of unfavorable meteorological conditions such as weak ground pressure, high humidity, low temperature, low wind speeds, and regional transport.

A novel bifunctional fluorescent and colorimetric probe for detection of mercury and fluoride ions.

A fluorescent and colorimetric probe L1 based on a simple coumarin derivative for detection of Hg and F ions was developed. Upon addition of Hg and F ions, L1 underwent desulfurization and desilylation, respectively, to induce marked increase in the fluorescence intensity and sharp color change from light yellow to dark purple and light brown, respectively. Probe L1 could be used for sensing and for quantitative measurement of Hg and F ions by both UV-vis and fluorescence spectra.

1-[(4-Chloro-phen-yl)(phen-yl)meth-yl]piperazine-1,4-diium bis-(trichloro-acetate)-trichloro-acetic acid (1/1).

In the title salt adduct, C(17)H(21)ClN(2) (2+)·2C(2)Cl(3)O(2) (-)·C(2)HCl(3)O(2), the Cl atom of the dication is disordered over two positions in a 0.915 (3):0.085 (3) ratio.

4-[(4-Chloro-phen-yl)(phen-yl)-meth-yl]-piperazin-1-ium picrate monohydrate.

The asymmetric unit of the title compound, C(17)H(20)ClN(2) (+)·C(6)H(2)N(3)O(7) (-)·H(2)O, contains a piperazin-1-ium cation, a picrate anion and one solvent water mol-ecule. The piperazene ring is protonated at one N atom and adopts a highly distorted chair conformation with the chloro-pheny(phen-yl)methyl substituent on the second N atom in an equatorial position. The crystal structure is stabilized by O-H⋯O, N-H⋯O and C-H⋯O hydrogen bonds.

Cinnarizinium picrate.

In the title salt {systematic name: 4-diphenyl-methyl-1-[(E)-3-phenyl-prop-2-en-1-yl]piperazin-1-ium 2,4,6-trinitro-pheno-late), C(26)H(29)N(2) (+)·C(6)H(2)N(3)O(7) (-), the cinnarizinium cation is protonated at the piperazine N atom connected to the styrenylmethyl group; the piperazine ring adopts a distorted chair conformaiton. In the crystal, bifurcated N-H⋯(O,O) hydrogen bonds link the components into two-ion aggregates.

Improved synthesis of mestranol and ethinyl estradiol (EE) related degradation products as authentic references.

Preparative chemical methods for the synthesis of 10 degradation or photodecomposition products of mestranol and ethinyl estradiol (EE) are described. The synthesized compounds are useful as reference materials and standards for pharmaceutical analysis of mestranol and EE as bulk chemical or in formulated product. New synthetic methods were presented and the known synthetic procedures were improved.

Methyl 3,4-O-isopropyl-idene-2-O-[(methyl-sulfan-yl)thio-carbon-yl]-β-l-arabinoside.

In the title compound, C(11)H(18)O(5)S(2), the six- and five-membered rings adopt a chair and an approximately planar conformation, respectively.

17α-Ethynyl-3-methoxy-estra-1,3,5(10),9(11)-tetraen-17-ol.

In the title compound, C(21)H(24)O(2), rings B, C and D adopt half-chair, distorted half-chair and envelope conformations, respectively. In the crystal structure, there is an inter-molecular O-H⋯O hydrogen bond. The mol-ecules are arranged in a head-to-tail fashion, with the meth-oxy and hydr-oxy groups forming a two-dimensional hydrogen-bond network.