Al2O3-coated BiVO4 Photoanodes for Photoelectrocatalytic Regioselective C−H Activation of Aromatic Amines

Photoelectrochemistry is becoming an innovative approach to organic synthesis. Generally, the current photoelectrocatalytic organic transformations suffer from limited reaction type, low conversion efficiency and poor stability. Herein, we develop efficient and stable photoelectrode materials using metal oxide protective layer, with a focus on achieving regioselective activation of amine compounds. Notably, our photoelectrochemistry process is implemented under mild reaction conditions and does not involve any directing groups, transition metals or oxidants. The results demonstrate that beyond photocatalysis and electrocatalysis, photoelectrocatalysis exhibits high efficiency, remarkable repeatability and good functional group tolerance, highlighting its great potential for applications.     

A new optical/electrochemical Na+ sensor based on platinum(II) complexes containing crown ether annelated dithiolate ligands

Two new platinum(II) complexes containing both 4,4'-di-tert-butyl-2,2'-bipyridine (dbbpy) and crown ether annelated dithiolate ligands, [Pt(dbbpy)(3O-C2S4)] (, 3O-C2S4(2-)=1,4,7-trioxa-10,13-dithiacyclopentadec-11-ene-11,12-dithiolate) and [Pt(dbbpy)(4O-C2S4)] (, 4O-C2S(4)2-=1,4,7,10-tetraoxa-13,16-dithiacyclooctadec-14-ene-14,15-dithiolate), have been prepared and characterized. These two complexes show intense electronic absorption bands in the UV-vis region due to the intramolecular mixed metal/ligand-to-ligand charge transfer transition, and they display solvatochromic behavior. The redox properties of these compounds have been investigated by cyclic voltammetry and complex shows a significant response for Na+ ions with a large positive shift of ca. 125 mV. Moreover, complex is very sensitive in detecting Na+ cations with an obvious change in color which can be conveniently observed with the naked eye.     

Simultaneous determination of anthraquinones in radix Polygoni multiflori by capillary gas chromatography coupled with flame ionization and mass spectrometric detection

A rapid, accurate and reliable analytical method was developed for the simultaneous determination of five major anthraquinones, aloe-emodin, chrysophanol, emodin, physcion, and rhein, in radix Polygoni multiflori, a traditional Chinese herbal medicine. The method comprises a fast ultrasonic extraction with methanol and derivatization with N,O-bis(trimethylsilyl)trifluoroacetamide (BSTFA)+1% trimethylchlorosilane (TMCS) followed by capillary gas chromatographic (GC) separation. The effect of reaction time on the derivatization of anthraquinones was examined. A baseline separation of the anthraquinone and internal standard derivatives was achieved in 15min. The detection limits range from 0.22 to 0.60microg/mL for the five anthraquinones. The calibration curves are linear over the concentration range studied (from the detection limits to 40.0microg/mL) with the squares of correlation coefficients, R2, greater than 0.998. The developed method was successfully applied to the simultaneous determination of anthraquinones in radix P. multiflori samples. The peak identification was confirmed using GC-MS. The contents of anthraquinones in radix P. multiflori samples studied were 27.41, 289.6, 64.22, 202.1, 288.6microg/g for chrysophanol, emodin, aloe-emodin, physcion, rhein, respectively. All relative standard deviations are less than 3.2%. The recoveries range from 80.2% to 119.3% for the five analytes. To the authors' best knowledge, this is the first GC method reported for the simultaneous determination of the five anthraquinones in radix P. multiflori.     

A multianalyte chemosensor on a single molecule: promising structure for an integrated logic gate

A novel fluorescent probe that possess both BODIPY and Rhodamine moieties has been designed for the selective detection of Hg(2+) and Ba(2+) ions on the controlling by a logic gate. The characteristic fluorescence of the Ba(2+)-selective OFF-ON and the Hg(2+)-selective fluorescence bathochromic shift can be observed, and the concept has been used to construct a combinational logic circuit at the molecular level. These results will be useful for further molecular design to mimic the function of the complex logic gates on controlling.     

Cytotoxicity of labdane-type diterpenoids from Hedychium forrestii

Two new labdane-type diterpenoids, hedyforrestin D (1) and 15-ethoxy-hedyforrestin D (2), and three known compounds, yunnancoronarin A (4), B (3) and C (5) were isolated from the rhizomes of Hedychium forrestii. The structure of the new diterpenoids was established as 6beta,15xi-dihydroxylabda-8(17),11,13-trien-15,16-olide (1), and 6beta-hydroxy-15xi-ethoxylabda-8(17),11,13-trien-15,16-olide (2) on the basis of spectroscopic analyses. In addition, the isolated compounds were evaluated for their cytotoxicity against the lung adenocarcinoma cells A549 and leukemia cells K562 through 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) assays. Of these, compounds 3 and 4 exhibited the most activity with IC(50) values of 0.92 and 2.20 microM, respectively, whereas 5 was inactive against A549 cells and 1 was inactive against both cell lines up to a concentration of 300.81 microM. This shows that both the hydroxy substitution and orientation of unsaturated lactone group in the five-membered ring of C-13 to C-16 seem to play an important role in the anti-tumor activities of human lung adenocarcinoma and leukemia.     

Preparation and structural characterization of the Ih and the D5h isomers of the endohedral fullerenes Tm3N@C80: icosahedral C80 cage encapsulation of a trimetallic nitride magnetic cluster with three uncoupled Tm3+ ions

We report an efficient method for the preparation and purification of the Ih and the D5h isomers of Tm3N@C80. Following preparation in a Kratschmer-Huffman electric-arc generator, the Tm3N@C80 isomers were obtained by a chemical separation process followed by a one-stage isomer selective chromatographic high-performance liquid chromatography (HPLC) separation (pyrenyl, 5PYE column). The HPLC chromatographic retention behavior on a pentabromobenzyl (5PBB) column suggests a charge transfer of approximately 6 electrons; [M3N] 6+@C80(6-) and the chromatographic retention mechanisms of the Ih and the D5h isomers of Tm3N@C80 on both 5PBB and 5PYE columns are discussed. Single-crystal X-ray diffraction data demonstrate that the Tm3N cluster has a planar structure but represents a tight fit for trapping the Tm3N cluster inside the I h - and the D 5h -C 80 cages. Specifically, the Tm atoms punch out the cage carbon atoms adjacent to them. The "punched out" effect can be demonstrated by cage radii and pyramidal angles at cage carbon atoms near the Tm atoms. The magnetic susceptibility (chiT) for Tm3N@ Ih -C80 was found to exhibit Curie-Weiss behavior with C = 23.4 emu.K/mol, which is consistent with the calculated value for three uncoupled Tm3+ ions by considering the spin and orbital contributions with no quenching of the orbital angular momentum ( L = 5, S = 1, and J = 6; Ccalcd = 23.3 emu.K/mol). The electrochemical measurements demonstrate that both the Ih and the D5h isomers of Tm3N@C80 have a large electrochemical gap.     

Ferroelectric heterobimetallic clusters with ferromagnetic interactions

Two homochiral trinuclear clusters, {(MeTp)2Fe2(CN)6Ni[(1R,2R)-chxn]2} (1) and {(MeTp)2Fe2(CN)6Ni[(1S,2S)-chxn]2} (2) [chxn = 1,2-diaminocyclohexane; MeTp = methyltris(pyrazolyl)borate], have been synthesized and structurally characterized. Ferroelectric and magnetic measurements reveal that they are rare examples of metal-organic compounds bearing ferroelectricity and intramolecular ferromagnetic interactions.     

Novel Designed PEG-Dicationic Imidazolium-Based Ionic Liquids as Effective Plasticizers for Sustainable Polylactide

A series of novel polyethylene glycol-dicationic imidazolium-based ionic liquids(mPEG-ILs)were synthesized by facile quaternization reaction from various elabor...     

On the Generalized Cartan Matrices Arising from k-th Yau Algebras of Isolated Hypersurface Singularities

Algebras and Representation Theory - Let (V,0) be an isolated hypersurface singularity defined by the holomorphic function $f: (mathbb {C}^{n}, 0)rightarrow (mathbb {C}, 0)$ . The k-th Yau...     

Coexistence of isospin I =0 and I=1 pairings in asymmetric nuclear matter

The coexistence of neutron-neutron (n-n),proton-proton (p-p),and neutron-proton (n-p) pairings is in-vestigated by adopting an effective density-dependent conta...