Pyrene-Based Cationic Fluorophores with High Affinity for BF4-, PF6-, and ClO4- Anions: Detection and Removal.

Anions play an indispensable role in the balance and regulation of the ecological environment and human health; however, excess anions can cause serious ecological and environment problems. Therefore, the detection and removal of excess anions in aqueous solution is not only a technological problem but also crucial for environmental protection. Herein, a set of water-soluble pyrene-based cationic fluorophores were synthesized, which exhibit high sensitivity for the detection of the anions BF4-, PF6-, and ClO4- via electrostatic interactions. Such fluorescent probes exhibit "turn-on" emission characteristics even at low concentrations of anions due to anion-π+ interactions. Moreover, these fluorescence probes act as efficient precipitating agents for the removal of the BF4-, PF6-, and ClO4- anions from an aqueous environment. This work opens up new avenues for future research on pyrene-based fluorophores as turn-on fluorescence probes for anion detection and as excellent precipitating agents in environmental settings.

A Turn-On Fluorescent Chemosensor for Cyanide Ion Detection in Real Water Samples.

We have designed and synthesized a novel simple colorimetric fluorescent probe with aggregation-induced emission (AIE) properties. Probe 5-(4-(diphenylamine)phenyl) thiophen-2-formaldehyde W exhibited a turn-on fluorescent response to cyanide ion (CN-), which induces distinct visual color changes. Probe W exhibited a highly selective and sensitive ratiometric fluorescence response for the detection of CN- over a wide pH range (4-11) and in the presence of common interferents. The linear detection of CN- over the concentration range of 4.00-38.00 µM (R 2 = 0.9916, RSD = 0.02) was monitored by UV-Vis absorption spectrometry (UV-Vis) with the limit of detection determined to be 0.48 µM. The linear detection of CN- over the concentration range of 8.00-38.00 µM was examined by fluorescence spectrophotometry (R 2 = 0.99086, RSD = 0.031), and the detection limit was found to be 68.00 nM. The sensing mechanisms were confirmed by 1H NMR spectroscopic titrations, X-ray crystallographic analysis, and HRMS. Importantly, probe W was found to show rapid response, high selectivity, and sensitivity for cyanide anions in real water samples, over the range of 100.17∼100.86% in artificial lake water and 100.54∼101.64% in running water by UV-Vis absorption spectrometry, and over the range of 99.42∼100.71% in artificial lake water and 100.59∼101.17% in running water by fluorescence spectrophotometry. Importantly, this work provides a simple and effective approach which uses an economically cheap and uncomplicated synthetic route for the selective, sensitive, and quantitative detection of CN- ions in systems relevant to the environment and health.

A New Cationic Fluorescent Probe for HSO3- Based on Bisulfite Induced Aggregation Self-Assembly.

In comparison with the numerous studies that have centered on developing molecular frameworks for the functionalization of fluorescent materials, less research has addressed the influence of the side chains, despite such appendages contributing significantly to the properties and applications of fluorescent materials. In this work, a new series of cationic fluorescent probes with AIE characteristics have been developed, which exhibit unique sensitivity for charge-diffusion anions, namely HSO3-, via the interactions of ions and the cooperation of the controllable hydrophobicity. The impact of the alkyl chain length attached at the cationic probes suggested that the fluorescent intensity and sensitivity of the probes could be partially enhanced by adjusting their aggregation tendency through the action of the hydrophobic effect under aqueous conditions. DLS and SEM images indicated that different particle sizes and new morphologies of the probes were formed in the anion-recognition-triggered self-assembly process, which could be attributed to the composite effect of electrostatic actions, Van der Waals forces and π-π stacking.

[Effects of adipokine chemerin on the improvement of islet function in diabetic mice by aerobic exercise and its mechanisms].

Objective: To investigate the effects of adipokines chemerin on the improvement of islet function caused by exercise in mice with diabetes, and the possible mechanism of glucagon-like peptide 1 (GLP-1). Methods: Male ICR mice were randomly divided into a control group fed with normal diet (Con, n=6) and a diabetic modeling group fed with 60% kcal high-fat diet (n=44). After 6 weeks, the diabetic modeling group was once given a fasting intraperitoneal injection of streptozotocin (100 mg/kg). The successfully modeled mice were divided into diabetes group (DM), diabetes plus exercise group (EDM), and diabetes plus exercise and exogenous chemerin group (EDMC), 6 in each group. Mice in exercise groups participated in a six-week modest intensity treadmill running exercise with a gradually increased load. Mice in the EDMC group were intraperitoneally injected with exogenous chemerin (8 µg/kg) from the 4th week of the exercise period, six days per week, and one time per day. And the other groups were untreated. Adipose chemerin knockout mice were constructed. Then they and the control mice were divided into 6 groups (n=4): Normal diet control group (Con-ND), Normal diet chemerin knockout heterozygote mice group (Chemerin(+/-)-ND), Normal diet chemerin knockout homozygotes mice group(Chemerin(-/-)-ND), High-fat diet control group (Con-HFD), High-fat diet chemerin knockout heterozygote mice group (Chemerin(+/-)-HFD), High-fat diet chemerin knockout homozygotes mice group (Chemerin(-/-)-HFD). They were fed with normal or high-fat diet for 11 weeks and oral glucose tolerance test (OGTT) was conducted. After the mice of each group were executed under anesthesia, the samples such as pancreas and colon were collected. Fasting blood glucose (FBG) and fasting insulin (FINS) levels in mice were measured, and the insulin resistance index (HOMA-IR) was calculated. HE staining was used to observe the structure of islets. ELISA was used to detect the GLP-1 level in serum. The mRNA levels of proglucagon (GCG) and chemerin in the colon were measured by real-time PCR. And the protein levels of GCG and chemerin in the colon were detected by Western blot. Results: Compared with the DM group, the vacuolar degeneration and shrinkage of islet cells in the EDM group were reduced, the islet structure was improved, while the levels of FINS, HOMA-IR and FBG were decreased significantly (P＜0.05 or P＜0.01). The colon and serum chemerin levels were decreased significantly(P＜0.05), while the colonic GCG mRNA and protein levels were increased significantly (P＜0.05 or P＜0.01). Compared with the EDM group, the islet cells in the EDMC group were shrunken, with unclear borders. The structure of the islets was damaged, and the levels of FINS, HOMA-IR and FBG were increased significantly (P＜0.01), while the mRNA and protein levels of GCG were decreased significantly (P＜0.05 or P＜0.01). Compared with the Con-HFD group, the blood glucose at 30, 90 and 120 min after oral glucose in the chemerin (-/-)-HFD group was significantly lower (P＜0.01), and the area under the blood glucose time curve was significantly lower (P＜0.01). The islets had clear structure, regular shape and well-defined boundaries, while the serum GLP-1 and colonic GCG protein levels were increased significantly(P＜0.05). Conclusion: Aerobic exercise improves the structure and function of pancreatic islets by reducing the level of chemerin in diabetes mice, which is related to the negative regulation of chemerin on GLP-1 level.

A Highly Selective Turn-On Fluorescent Probe for the Detection of Zinc.

A novel turn-on fluorescence probe L has been designed that exhibits high selectivity and sensitivity with a detection limit of 9.53 × 10-8 mol/L for the quantification of Zn2+. 1H-NMR spectroscopy and single crystal X-ray diffraction analysis revealed the unsymmetrical nature of the structure of the Schiff base probe L. An emission titration experiment in the presence of different molar fractions of Zn2+ was used to perform a Job's plot analysis. The results showed that the stoichiometric ratio of the complex formed by L and Zn2+ was 1:1. Moreover, the molecular structure of the mononuclear Cu complex reveals one ligand L coordinates with one Cu atom in the asymmetric unit. On adding CuCl2 to the ZnCl2/L system, a Cu-Zn complex was formed and a strong quenching behavior was observed, which inferred that the Cu2+ displaced Zn2+ to coordinate with the imine nitrogen atoms and hydroxyl oxygen atoms of probe L.

A 1-Hydroxy-2,4-Diformylnaphthalene-Based Fluorescent Probe and Its Detection of Sulfites/Bisulfite.

A novel 1-hydroxy-2,4-diformylnaphthalene-based fluorescent probe L was synthesized by a Knoevenagel reaction and exhibited excellent sensitivity and selectivity towards sulfite ions (SO32-) and bisulfite ions (HSO3-). The detection limits of the probe L were 0.24 µM using UV-Vis spectroscopy and 9.93 nM using fluorescence spectroscopy, respectively. Furthermore, the fluorescent probe L could be utilized for detection in real water samples with satisfactory recoveries in the range 99.20%~104.30% in lake water and 100.00%~104.80% in tap water by UV-Vis absorption spectrometry, and in the range 100.50%~108.60% in lake water and 102.70%~103.80% in tap water by fluorescence spectrophotometry.

Dynamic Coordination between a Triphenylamine-Functionalized Salicylaldehyde Schiff Base and a Copper(II) Ion.

The coordination between a ligand and a metal is a spontaneous and uncontrollable process. In this Article, we successfully observe the formation of metal coordination in a triphenylamine-functionalized salicylaldehyde Schiff base with a copper(II) ion. The ligand TPA-Py first reacts with Cu2+ in a stepwise process to afford the dynamic complex TPA-Py@Cu2+ ([ligand]:[Cu2+] = 1:1), which further reacts with an extra copper(II) ion to afford 2TPA-Py@4Cu2+ with the following stepwise (or cumulative) stability constants: K1 = 4.0694 × 103 and K2 = 1.0761 × 106, respectively. The entire metal coordination process can be visualized, and the coordination mode of the probe toward copper was further evaluated by ultraviolet-visible/fluorescence spectra, single-crystal X-ray diffraction, density functional theory calculations, high-resolution mass spectra, and nuclear magnetic resonance spectroscopic titrations. Compound TPA-Py exhibited excellent sensitivity and specificity toward copper(II) ions in THF/water media with a low limit of detection of 2.687 × 10-7 mol L-1. In addition, TPI-An-Py can be applied to the detection of Cu2+ in real samples with satisfactory recoveries in the range of 100-112% in lake water and 98-101% in tap water. This Article not only reports an excellent fluorescence probe for copper(II) ion detection but also presents an instance for more fully understanding the metal coordination process.

A Simple Turn-off Schiff Base Fluorescent Sensor for Copper (II) Ion and Its Application in Water Analysis.

An aniline-functionalized naphthalene dialdehyde Schiff base fluorescent probe L with aggregation-induced enhanced emission (AIEE) characteristics was synthesized via a simple one-step condensation reaction and exhibited excellent sensitivity and selectivity towards copper(II) ions in aqueous media with a fluorescence " turn-off " phenomenon. The detection limit of the probe is 1.64 × 10-8 mol·L-1. Furthermore, according to the results of the UV-vis/fluorescence titrations, Job's plot method and 1H-NMR titrations, a 1:2 stoichiometry was identified. The binding constant between L and Cu2+ was calculated to be Ka = 1.222 × 103. In addition, the AIEE fluorescent probe L could be applied to detection in real water samples with satisfactory recoveries in the range 99.10-102.90% in lake water and 98.49-102.37% in tap water.

Twisted Schiff-base macrocycle showing excited-state intramolecular proton-transfer (ESIPT): assembly and sensing properties.

A Schiff-base macrocyclic host (MH) showing ESIPT and AIEE is reported for the first time; the fluorescent macrocycle exhibited good pH tolerance and could serve as a probe for Cu2+ and Fe3+ ion sensing and removal. In addition, a series of size-tunable nanoparticles was fabricated by the self-assembly of free MH and its coordination complex with Fe3+ in THF/water solution.

Organic core-shell-shaped micro/nanoparticles from twisted macrocycles in Schiff base reaction.

Functional self-assemblies derived from noncovalent interactions such as lipid vesicles and DNA chiral double helices are a typical feature of natural life activity. Because of this phenomenon, a self-assembly approach for various functional organic particles is a desirable objective in supramolecular chemistry. Here, we report the discovery of enantiomeric conformers from a twisted macrocyclic host (MH), which was obtained from an achiral precursor by Schiff base reaction. Further studies suggest that a series of unexpected and stable core-shell-based organic micro/nanospheres can be directly precipitated from a simple reaction solution with high yield. A single-crystal X-ray diffraction analysis of MH revealed that the unusual C-H···π interaction triggered self-assembly of the enantiomeric forms in the solid state plays an important role in the formation of the core-shell-shaped organic particles.

Solvent-Switched Schiff-Base Macrocycles: Self-Sorting and Self-Assembly-Dependent Unconventional Organic Particles.

Organic reaction is a powerful and versatile tool for the creation of various new substrates and materials. However, there have been few reports of the direct fabrication of organic particles by organic reactions. Herein, we report that water as a co-solvent can efficiently switch a [2 + 2] macrocycle (3) to a [1 + 1] macrocycle (4) in a Schiff-base reaction from the same precursors at room temperature. Unexpectedly, a series of tunable organic micro/nanoparticles, including solid microspheres, core-shell spheres, and vesicles, could be directly precipitated in one-step from the reaction medium with high yield. X-ray structure analysis and other characterizations indicated that social self-sorting and narcissistic self-sorting of the macrocyclic frameworks of 3 and 4 through noncovalent interactions play crucial roles in the formation of such organic particles. Most interestingly, the facile and mild fabrication conditions of the particles allowed us to accurately and in situ monitor their intermediate formation by controlling the reaction time. This work thus provides an advancement of the fabrication of tunable organic particles.

Effect of Modified Wuzi Yanzong Pill () on Tip60-Mediated Apoptosis in Testis of Male Rats after Microwave Radiation.

OBJECTIVE: To investigate the effect of a modified Wuzi Yanzong Pill (, WZYZP) on the male rats' testis after microwave radiation, as well as its potential mechanism. METHODS: Forty-five male rats were randomly assigned to three groups: the control group, the radiation group, and the WZYZP group. The rats in the radiation group and WZYZP group were exposed to microwave radiation for 15 min once, while the rats in the control group were not exposed to any radiation. The rats in the WZYZP group were given a modified of WZYZP by gavage daily for 7 days. Apoptosis in the testis was evaluated using terminal-deoxynucleoitidyl transferase mediated nick end labeling (TUNEL) assay. Histopathological alterations of the testis were observed by haematoxylin-eosin (HE) staining. Tat-interactive protein, 60kD (Tip60) and p53 expressions were determined by Western blotting. RESULTS: The apoptosis index (AI) in the radiation group was higher than that of the WZYZP group and control group on day 1 (D1), day 7 (D7) day 14 (D14) after radiation (P<0.05). The seminiferous tubules were of normal morphology in the control group. In the radiation group, the partial seminiferous tubules were collapsed, basement membranes of the seminiferous epithelia became detached. WZYZP could restore the morphological changes. There was no expression of Tip60 among the three groups on D7 and D14. The expression of p53 was higher in the radiation group than in the control group (P<0.05). WZYZP could down-regulate the rising p53 induced by radiation on D7 and D14 (P<0.05). CONCLUSION: A modified WZYZP may affect germ cells, and its protective effects may partly result from its ability to intervene in Tip60 mediated apoptosis.

Structural Diversity of Six Coordination Polymers Based on the Designed X-Shaped Ligand 1,1,1,1-Tetrakis[(3-pyridiniourea)methyl]methane.

In this study, six coordination polymers (CPs), {[Ag2(L)(CF3SO3)]·CF3SO3·2H2O·DMF}n (1), {[Ag(L)]·SbF6·4DMF·H2O}n (2), {[Zn(L)0.5(I)2]·3.75H2O}n (3), {[Cd2(L)(I)4(H2O)(DMF)]·4H2O·3DMF}n (4), {[Hg2(L)(I)4]·H2O·4DMF}n (5) and {[Hg2(L)(Cl)4]·2H2O·3DMF}n (6), were obtained based on the designed X-shaped urea-based ligand. X-ray single crystal diffraction analysis revealed that complex 1 displayed a 3D (3,4)-connected {6·8²}{64·8²}-tcj net. Complex 2 featured a 2D 4-connected {4³·6³} sheet. Complexes 3 and 5 exhibited a 1D polymeric loop chain. Complex 4 displayed a 1D polymeric fishbone chain. Complex 6 showed a 2D 4-connected {44·6²}-sql sheet. Structural comparison revealed that not only the metal ions, but also the anions played crucial roles in the control of final structures.

A one-dimensional coordination polymer formed from the reaction of 1,1-diphenyl-3,3'-[(1R,2R)-cyclohexane-1,2-diylbis(azanediyl)]dibut-2-en-1-one with MnCl2·4H2O.

In the title coordination polymer, catena-poly[[dichloridomanganese(II)]-µ-1,1-diphenyl-3,3'-[(1R,2R)-cyclohexane-1,2-diylbis(azaniumylylidene)]dibut-1-en-1-olate-κ(2)O:O'], [MnCl2(C26H30N2)]n, synthesized by the reaction of the chiral Schiff base ligand 1,1-diphenyl-3,3'-[(1R,2R)-cyclohexane-1,2-diylbis(azanediyl)]dibut-2-en-1-one (L) with MnCl2·4H2O, the asymmetric unit contains one crystallographically unique Mn(II) ion, one unique spacer ligand, L, and two chloride ions. Each Mn(II) ion is four-coordinated in a distorted tetrahedral coordination environment by two O atoms from two L ligands and by two chloride ligands. The Mn(II) ions are bridged by L ligands to form a one-dimensional chain structure along the a axis. The chloride ligands are monodentate (terminal). The ligand is in the zwitterionic enol form and displays intramolecular ionic N(+)-H...O(-) hydrogen bonding and π-π interactions between pairs of phenyl rings which strengthen the chains.

Polymeric di- and discrete trinuclear silver(I) assemblies incorporating gamma-carbon bonded, neutral acetylacetone-imine motifs assembled from racemic and diastereopure N,N'-bis(acetylacetone)cyclohexanediimine units.

Diastereopure (1R,2R)-N,N'-bis(acetylacetone)cyclohexanedi-imine L(1) and its corresponding (1R,2R)L(1)/(1S,2S)L(2) enantiomeric mixture react with AgNO(3) to yield the unusual coordination polymer [Ag(2)(L(1))(L(2))(NO(3))(2)](n) (1) and the unique trimetallic discrete species {[Ag(3)(L(1))(3)(micro(3)-O,O,O-NO(3))(H(2)O)(3)](2)(NO(3))}(NO(3))(3) x 8.5H(2)O (2) which incorporates a symmetrical micro(3)-bridging nitrato group that gives rise to a C(3)-symmetric triskelion motif; both species also feature gamma-carbon eta(1) aryl-like coordination of neutral bridging acetylacetone-imine units to the respective Ag(I) centres.

4-(4-Oxopent-2-en-2-yl-amino)-1,2,4-triazol-1-ium-5-thiol-ate.

In the title compound, C(8)H(12)N(4)OS, an intra-molecular N-H⋯O hydrogen bond links the imine N atom to the oxo O atom. In the crystal, mol-ecules are linked by inter-molecular N-H⋯O and N-H⋯S hydrogen bonds, forming a two-dimensional framework.

Four zinc(II) helical coordination polymers and 78-membered six-node zinc metallacycle assembled from diastereopure N,N'-bis(acetylacetone)cyclohexanediimine.

The interaction of the diastereopure N,N'-bis(acetylacetone)cyclohexanediimine ligands, L(1)(1R,2R), L(2)(1S,2S), and their 1:1 mixture, with Zn(II) chloride has been investigated. Four new coordination polymers, [ZnL(1)Cl2 x H2O]n (1), [ZnL(2)Cl2 x H2O]n (2), [ZnL(2)Cl2]n (3), and [Zn6(L(2))6Cl12 x 2 H2O]n (4), each consisting of an infinite single helical chain displaying different pitches and/or handedness have been isolated. The complexed Schiff base ligands are present in their deprotonated enol forms, and the nitrogen atoms, which do not coordinate, are protonated because of proton transfer from the adjacent enol oxygen (coupled with concomitant N-H...O bond formation); each bound ligand is thus pseudo-zwitterionic. The respective zinc centers are bound to two chloro ligands and two oxygen donors from acacH-imine units belonging to different N,N'-bis(acetylacetone)cyclohexanediimine ligands such that the coordination at each zinc is distorted tetrahedral. Compounds 1 and 2, prepared from enantiopure L(1) and L(2), respectively, are enantiomers with similar structures, with the helical pitch in each being 17.0 A. Overall, the structure of 3 may be described as a one-dimensional helical chain with a pitch of 17.3 A, with each period corresponding to two L(2) ligands and two metal centers. The structure of [(Zn6L(2)6Cl12) x 2 H2O]n (4) contains six Zn(II) centers connected via six L(2) ligands to form a "bowed" helical repeat unit, with the pitch of the helix corresponding to 43.5 A. Supramolecular (intra- and intermolecular) aspects of all these unusual polymeric structures are discussed. Finally, the synthesis and characterization of an unprecedented six zinc-node discrete supramolecular assembly, [Zn6(L(1))3(L(2))3Cl12] (5), incorporating a 78-membered metallacycle, is also reported.

3,3'-Dibromo-4,4'-[(1R,2R)-cyclohexane-1,2-diyldiimino]dipent-3-en-2-one.

The asymmetric unit of the title compound, C(16)H(24)Br(2)N(2)O(2), contains two independent mol-ecules, each which has two intra-molecular N-H⋯O hydrogen bonds linking the amine N atoms to the enolic O atoms of the same acacH-imine unit. In the crystal, the mol-ecules are lined up by inter-molecular weak C-H⋯O hydrogen bonds, forming two vertical each other two-dimensional chains along the a axis and b axis of the unit cell, respectively.

5,7-Dihydroxy-6,4'-dimeth-oxyflavone.

In the title compound, C(17)H(14)O(6), the benzopyran ring system is essentially planar and forms a dihedral angle of 6.84 (4)° with the other benzene ring. In the crystal structure, centrosymmetrically related mol-ecules are linked into dimers by O-H⋯O hydrogen bonds. The crystal packing is controlled by C-H⋯π and π-π stacking inter-actions involving the benzopyran and benzene rings, with centroid-centroid distances between 3.645 (2) and 3.986 (2) Å.