A 3,5-dinitropyridin-2yl Substituted Flavonol-based Fluorescent Probe for Rapid Detection of H2S in Water, Foodstuff Samples and Living Cells.

A novel flavonol-based fluorescent probe, Fla-DNT, has been synthesized for the rapid and specific detection of H2S. Fla-DNT exhibits excellent selectivity and anti-interference properties, a short response time (4 min), large Stokes shift (138 nm), and low detection limit (1.357 µM). Upon exposure to H2S, Fla-DNT displays a remarkable increase in fluorescence intensity at 542 nm. Meanwhile, the recognizing site of H2S was predicted through Electrostatic potential and ADCH charges calculations, while the sensing mechanism of H2S was determined via HRMS analysis and DFT calculation. More importantly, the probe owes multiple applications, such as a recovery rate ranging from 92.00 to 102.10% for detecting H2S in water samples, and it can be fabricated into fluorescent strips to track H2S production during food spoilage by tracking color changes, thereby enabling real-time monitoring of food freshness. The bioimaging experiments demonstrate the capability of Fla-DNT to detect both endogenous and exogenous H2S in living cells. These results provide a reliable method and idea for H2S detection in complex environments.

Multiple Applications of a Novel Fluorescence Probe with Large Stokes Shift and Sensitivity for Rapid H2S Detection.

Herein, a novel fluorescence probe Fla-DNP based on flavonol has been designed and synthesized for rapid, specific detection of H2S. With the addition of H2S, Fla-DNP triggered thiolysis and released Fla displaying the "turn-on" fluorescence response at 566 nm, which is consistent with the reaction site predicted by calculating Electrostatic potential and ADCH charges. As an easily available H2S probe, Fla-DNP has the advantages of high selectivity, anti-interference, low detection limit (0.834 µM), short response time (6 min), and large Stokes shift (124 nm). The sensing mechanism of H2S was determined by HRMS analysis and DFT calculation. Moreover, Fla-DNP processes a wide range of multiple applications, including the detection of H2S in environmental water samples with good recovery rates ranging from 89.6% to 102.0%, as well as tracking the production of H2S during food spoilage. Meanwhile, the probe exhibits superior biocompatibility and can not only be available used for H2S detection in living cells but be further designed as an H2S-activated CO photoreleaser, based on which it can be developed as a targeted anti-cancer drug. A novel fluorescence probe Fla-DNP was synthesized utilizing 4-dimethylaminobenzoxanthone fluorescent dye (Fla) as the fluorophore, 2, 4-dinitrobenzenether group (DNP) as the recognition group, which can rapidly respond to H2S with high selectivity, anti-interference, low detection limit (0.834 µM), short response time (6 min), and large Stokes shift (124 nm) characteristics. The practical applications of Fla-DNP were further explored in water, foodstuffs samples and living cells. It is reflected that Fla-DNP can not only track H2S in complex environment water, but also can detect H2S produced during foodstuffs spoilage to monitor food freshness. More importantly, Fla-DNP can be available used for H2S detection in living cells and utilize the properties of the photoinduced release of CO from flavonols to be designed as a bifunctional platform for H2S detection and CO release. It is demonstrated that H2S-activated CO photoreleaser Fla-DNP has promise for development as an anti-cancer drug.

Counterion-Controlled Formation of Layered Honeycomb and Polythreading Uranyl Networks and the Highly Sensitive and Selective Detection of Fe3+ in Aqueous Media.

Under hydrothermal conditions, six uranium coordination polymers were obtained by employing the ligand of tris(2-carboxyethyl) isocyanurate (H3tci) and different combinations of d-block metal ions (Mn2+, Co2+, Zn2+, Ni2+) or N-donors (triethylamine (Et3N), 2,2'-bipyridine (2,2'-bipy)). Three uranium polymers [(UO2)2(tci)2]1/2-·[Mn2(µ2-O)(H2O)8]1/2+·2H2O (1), [(UO2)2(tci)2]1/2-·[Co2(µ2-O)(H2O)8]1/2+ (2), and [(UO2)2(tci)2]1/2-·[Zn2(µ2-O)(H2O)8]1/2+·2H2O (3) containing transition metal hydrated ions, crystallized as two-dimensional coordination polymers with the common (6, 3) net topology. X-ray crystal structures of 1-3 display that they have similar honeycomb-like frameworks with all ligands bis-chelating. [UO2(tci)]-3·[Ni(H2O)6]2+(H3O)+·2H2O (4) and [UO2(tci)]-·[NH(CH2CH3)3]1/3+·(2H3O+)1/3 (5) are made up of four interlocked sets and exhibit the 4-fold-interpenetrated frameworks. [UO2(tci)]-·(C10H9N2)+·H2O (6) comprises the 2,2'-bipy cation as counterion and represents a 2D grid layered structure. Additional metals and the N-donors are all free in the complexes, acting as the templates and compensation of the charge equilibrium. The solid-state emission spectra indicate that all of the synthesized compounds own fluorescence emissions. Furthermore, the results of the quenching ability of Fe3+ for complexes 5 and 6 exhibit their highly sensitive and selective detection for Fe3+ ions. Moreover, the uranium complexes can be used as a potential probe for Fe3+ in aqueous solutions.

Magnetic-heteropolyacid mesoporous catalysts for deep oxidative desulfurization of fuel: The influence on the amount of APES used.

Magnetic-heteropolyacid mesoporous catalysts have been obtained, in which magnetic Fe3O4 in the center of MCM-41 mesoporous materials and APES (3-aminopropyl-triethoxysilane) used to link heteropolyacid. To noted, for the various molar ratio APES used in the synthesized process, different numbers of -OCH3 were exposed in the final products (zero, one and two), named Fe@MP-1, Fe@MP-2 and Fe@MP-3, respectively. Interestingly, the three kinds of catalysts exhibited the various DBT removal efficiency during the oxidative desulfurization process, mainly due to their structure variance leading to be the research focus in this work. Among them, under the oxygen in air as oxidant, Fe@MP-1, with no -OCH3 exposed outside, showed the excellent desulfurization activity with 100% DBT conversion in 90 min and behaved nearly no obvious decrease after at least 8 recycling times. Thus, the certain amount of APES, used to link active components with supporters, is suggested as an effective aspect to increase the oxidative desulfurization efficiency and maybe the different types of linkage also show the various influence, which will be focused on in our further researches.

[Application of apparent diffusion coefficient in children aged 2-12 years with intellectual disability/global developmental delay who have normal conventional brain MRI findings].

OBJECTIVE: To study the value of fast spin-echo diffusion weighted imaging (TSE-DWI) apparent diffusion coefficient (ADC) in children aged 2-12 years with intellectual disability (ID)/global developmental delay (GDD) who have normal conventional brain MRI findings. METHODS: A total of 578 children with normal conventional brain MRI findings who met the diagnostic criteria for ID/GDD and 375 normal children were enrolled. Their imaging and clinical data were collected. All children underwent scanning with brain TSE-DWI sequence and routine sequence. ADC values of each brain region were compared between normal children with different ages, as well as between children with different degrees of ID/GDD in each age group. The influence of Adaptive Behavior Assessment System-II (ABAS-II) score on ADC values of each brain region was analyzed. RESULTS: For the normal children, the ADC values of the frontal and temporal white matter, the corpus callosum, the inner capsule, the centrum semiovale, the cerebellar dentate nucleus, the optic radiation, the thalamus, the lenticular nucleus, and the caudate nucleus gradually decreased with age (P<0.05). ADC values of the deep white matter, the shallow white matter, the deep gray matter nuclei, and the shallow gray matter increased with the increase in the degree of ID/GDD in the ID/GDD children aged 4-6 years (P<0.05). In the children with ID/GDD, the ADC values of the deep white matter, the shallow white matter, and the deep gray matter nuclei decreased with age (P<0.05). The ADC values of the children with ID/GDD decreased with the increase in ABAS-II score (P<0.05). CONCLUSIONS: ADC can reflect the subtle structural changes of brain regions in children with ID/GDD who have normal conventional brain MRI findings. It may be associated with social adaptation. It can provide an objective basis for the quantitative diagnosis of ID/GDD in children.

Preparation of mesoporous Cs-POM@MOF-199@MCM-41 under two different synthetic methods for a highly oxidesulfurization of dibenzothiophene.

Two different synthetic methods, the direct method and the substitution method, were used to synthesize the Cs-POM@MOF-199@MCM-41 (Cs-PMM), in which the modified heteropolyacid with cesium salt has been encapsulated into the pores with the mixture of MOF and MCM-41. The structural properties of the as-prepared catalysts were characterized using various analytical techniques: powder X-ray diffraction, FT-IR, SEM, TEM, XPS and BET, confirming that the Cs-POM active species retained its Keggin structure after immobilization. The substitution method of Cs-PMM exhibited more excellent catalytic performance for oxidative desulfurization of dibenzothiophene in the presence of oxygen. Under optimal conditions, the DBT conversion rate reached up to 99.6% and could be recycled 10 times without significant loss of catalytic activity, which is mainly attributed to the slow leaching of the active heteropolyacid species from the strong fixed effect of the mixture porous materials.

Photocatalytic oxidation desulfurization of model diesel over phthalocyanine/La0.8Ce0.2NiO3.

A series highly efficient and stable metallophthalocyanine/La0.8Ce0.2NiO3 (ML/LCNO) photocatalysts were prepared by a facile sol-gel and immersion method. The as-prepared samples were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), TEM, N2 adsorption-desorption, and UV-Vis. The results revealed that LCNO calcined at 700°C possessed a perovskite structure with porous, and phthalocyanine not only adsorbed on the surface but also loaded in the pores of the LCNO oxide. The photocatalytic activities of the samples were evaluated by the photocatalytic oxidation of dibenzothiophene (DBT) under simulated sunlight irradiation. It was found that either macrocyclic structure or center metal of phthalocyanine had great influences on the photocatalytic activity of ML/LCNO. The oxidative reactivity of the different macrocycles was found in the order of MPc/LCNO>MTAP/LCNO>MPTpz/LCNO; which of different center metals was CoL/LCNO>FeL/LCNO>MnL/LCNO>NiL/LCNO>CuL/LCNO. The catalysts were reused several times with a slight decrease in activity. Furthermore, this kinetics of photocatalytic oxidation of DBT indicated that the reaction was a pseudo-first-order reaction.

A series of lanthanide-organic polymers incorporating nitrogen-heterocyclic and aliphatic carboxylate mixed-ligands: structures, luminescent and magnetic properties.

Seven new lanthanide-organic coordination polymers incorporating both nitrogen heterocyclic dicarboxylate and various auxiliary ligands, {[Ln(3)(Hpimda)(4)(mu(2)-HCOO).5H(2)O].H(2)O}(n)} Ln = Sm (1), Ln = Eu (2), Ln = Gd (3), Ln = Dy (4), Ln = Ho (5), {[Ce(2)(Hpimda)(2)(mu(4)-C(2)O(4)).8H(2)O].2H(2)O}(n) (6), {[Yb(2)(pyda)(mu(4)-C(2)O(4))(2).4H(2)O].3H(2)O}(n) (7) (H(3)pimda = 1H-2-propyl-4,5-imidazoledicarboxylic acid, H(2)pyda = 2,6-pyridinedicarboxylic acid) have been fabricated successfully and characterized systematically. Complexes 1-5 are isomorphous and isostructural, and are built from two-dimensional (2-D) double-decker networks based on the tetranuclear basic carboxylate as a secondary building unit (SBU). Both polymers 6 and 7 feature a (3,4)-connected 3-D framework consisting of 2-D lanthanide-organic hexagonal grids, which are further interlinked via the mu(4)-oxalate ligand. The results of magnetic determination show the same end-to-end bridging fashion of formate group results in different magnetic properties occurring between lanthanide centers. The luminescence emission spectra of the complexes vary depending on the lanthanide ion present.

{2,6-Bis[(4-bromo-phen-yl)imino-meth-yl]pyridine-κN,N',N''}trichlorido-chromium(III).

In the title compound, [CrCl(3)(C(19)H(13)Br(2)N(3))], the Cr(3+ )ion is coordinated by the tridentate 2,6-bis-[(4-bromo-phen-yl)imino-meth-yl]pyridine Schiff base ligand in a fac-octa-hedral geometry. The dihedral angles between the pyridine and benzene rings are 23.9 (6) and 70.7 (1)°.

[2,6-Bis(p-tol-ylimino-meth-yl)pyridine-κN,N',N'']dichloridocopper(II).

The title compound, [CuCl(2)(C(21)H(19)N(3))], lies on a twofold rotation axis that passes through the N(pyrid-yl)-Cu bond; this symmetry element relates one half of the organic ligand to the other as well as one Cl ligand to the other. The three N atoms span the axial-equatorial-axial sites of the trigonal-bipyramidal coordination polyhedron; the geometry of the Cu(II) atom is 31% distorted from trigonal-bipyramidal (towards square-pyramidal along the Berry pseudorotation pathway).

[2,6-Bis(6-methyl-quinolin-2-yl)pyridine-κN,N',N'']dichloridomanganese(II).

In the mol-ecule of the title compound, [MnCl(2)(C(25)H(19)N(3))], the three N atoms span the axial-equatorial-axial sites of the trigonal-bipyramidal coordination polyhedron; the geometry of the Mn(II) atom is 34% distorted from trigonal-bipyramidal (towards square-pyramidal along the Berry pseudorotation pathway). One of the Cl atoms is disordered over two positions in a 0.82 (3):0.18 (3) ratio. Weak inter-molecular C-H⋯Cl hydrogen bonding occurs in the crystal structure.

[2,6-Bis(6-methyl-quinolin-2-yl)pyridine-κN,N',N'']dichloridoiron(II).

In the mol-ecule of the title compound, [FeCl(2)(C(25)H(19)N(3))], the three N atoms span the axial-equatorial-axial sites of the trigonal-bipyramidal coordination polyhedron; the geometry of the Fe(II) atom is 32% distorted from trigonal-bipyramidal (towards square-pyramidal along the Berry pseudorotation pathway). One of the Cl atoms is disordered over two positions in a 0.938 (11):0.062 (11) ratio. Inter-molecular C-H⋯Cl hydrogen bonding occurs in the crystal structure.

4-Hydr-oxy-1-oxo-1,2-dihydro-phthalazine-6,7-dicarboxylic acid dihydrate.

In the crystal structure of the title compound, C(10)H(6)N(2)O(6)·2H(2)O, the OH and NH groups each serve as a hydrogen-bond donor to one acceptor site whereas the water mol-ecules each serve as a hydrogen-bond donor to two acceptor sites. The hydrogen-bonding scheme gives rise to a three-dimensional network.