Journal of the Chinese Chemical Society

Spectra of UV-vis absorption, and emission (295 K and 77K) of difluoro-substituted triscarbene iridium complexes, fac-Ir(dfpmi)₃ display emission in deep blue/near UV which has the highest emission energy for iridium complexes. The vibronic structure, small rigidochromic shift in the lowtemperature, and the measured lifetime data imply the emitting state to be mainly ³π-π*.

We applied the adiabatic approximation method to the intramolecular vibrational redistribution and energy transfer of dipeptides and their cation radicals. Both the IVR and the energy transfer rates of GlyTyr and LeuTyr molecules and their ions are faster than that of the molecular dissociation process. Thus the RRKM theory is suitable for investigating the photodissociation process of dipeptides.

The anthracene bridge mediates the electronic communication between the two porphyrin units in the dimer while the anthraquinone bridge interrupts the communicaiton. This system can be exploited in the application of molecular switches.

A new Y₃OF₃S₂:Ce3³⁺ phosphor with a quantum efficiency of 40% has been discovered to emit yellow-orange luminescence under excitation at near UV and shows broadband yellow-orange emission peaking at 610 nm.

This phenomenon was observed in the X-ray examination of Chen's oil paintings, which showed up to two additional paintings beneath the surface of the painting “Back of a Seated Nude”. It distinctively showed the frontal view of a nude woman and a portrait of a man beneath the piece's surface.

A practical procedure is introduced to functionalize MWNT with Nq. The Nq/MWNT was analyzed by using different methods. This electrochemical sensor could be applied to the detection of D-PA and CAP with high selectivity.

A series of Co(II), Cu(II), Mn(II) and Zn(II) bimetallic complexes have been synthesized with the schiff base ligand 2-(bis-2-hydroxyl phenylidene) diimine (L) derived from the condensation of hydrazine and salicylaldehyde. The synthesized ligand and bimetallic complexes were characterized by different spectroscopic techniques. The biological studies showed that the ligand exhibited lower value of antifungal and antibacterial activities than bimetallic complexes.

Ce-doped TiO₂ hollow fiber photocatalysts have been synthesized. Higher degradation percentage of methyl blue has been achieved with these TiO₂ hollow fibers with 0.5 mol% Ce-doped TiO₂ fiber showing the highest activity.

Relationships between eight structural types of toroidal carbon nanotubes can be summarized as a transformation cube with vertices denoting these distinct structures. The edges and diagonals on the top and bottom faces stand for the four different transformations that connect them.

An efficient synthesis of 5,6-dimethoxy-1-naphthol (1) and 5,6-dimethoxy-2-naphthol (2) was achieved via a key oxidation of 1,5-naphthalenediol (4) and 6-bromo-2-naphthol (9) to corresponding quinones by Fremy's salt. Ascribed to the ready availability of starting materials together with the operational simplicity of most reactions in the presented protocol, this synthetic strategy was much useful from the practical point of view.

By the iodine-promoted oxidative condensation, N-glycans are converted to the naphthimidazole (NAIM) derivatives with a UV/fluorescence sensitive chromophore to facilitate the chromatographic analysis and to improve the ionization efficiency in mass spectrometry by increase of the hydrophobicity with NAIM moiety. This method is applicable to the analysis of N-glycans obtained from natural source in small quantity.

A reversible color change is observed in the cyanide-bridged complex, [Y(DMF)₄(H₂O)₃(μ-CN)Fe(CN)₅]·H₂O, at elevated pressure.

Long time MD simulations of the GB1 β-hairpin peptide reveal the site-dependent properties via temperature-dependent unfolding transition. These properties may provide a foundation for the interpretation of probe-dependent experimental results.

The Fe K-edge XANES features marked by P, A, B, and C are elucidated by FDM and TDDFT calculations. The pre-edge peak P is mainly the transition of 1s(Fe) → 3d_z²(Fe)(mixing with 3p_z(S)), and feature A is related to the Fe-S bonding. The feature B and C are corresponding to π* and σ* antibonding orbital of Fe-N bond, respectively.

Molybdate sulfuric acid (MSA) as a highly efficient catalyst has been employed for the modified Paal–Knorr synthesis of some novel and known pyrroles under solvent-free conditions. This method has advantages such as the use of very low amounts of a recyclable catalyst, avoidance of organic solvents, and high product yields.

Hf₅Al_3-xSb_x (x = 0.70, 1.44, 2.14) were synthesized and appeared within ranges 0 ≤ x ≤ 1.0 and 2.0 ≤ x ≤ 2.5 for Mn₅Si₃ and W₅Si₃ structural types, respectively.

Two pathways are proposed to explain the fibril growth from soluble Aβ peptide. Two Aβ peptides chelate with copper ion in either parallel or anti-parallel orientation, and then the aggregate grows to form fibril by the incoming metallated Aβ peptides.

The photoreaction of three cobaloxime complex crystals with chiral 1-tert-(butoxy- carbonyl)ethyl group showed the inversion of the chiral group with retention of the single crystal form. The reaction cavity well explains the reaction mechanism.

SBA-15 supported Cu-Au bimetallic nanoparticles are studied under different Cu/Au ratios and temperature. The addition of gold promotes the catalytic performance, reducing the amount of oligomers formed on the catalyst's surface. A synergistic effect between copper and gold is also displayed. The bimetallic catalyst with Cu/Au ratio at 1/3 has both better conversion and selectivity between 160-200 °C, providing the opportunities to lower the operating temperature (>200 °C) of copper.

A large manganese-doped polyoxotitanate nanocluster, Ti₁₄MnO₁₄(OH)₂(OEt)₂₈, has been synthesized and analyzed by crystallographic, spectroscopic and theoretical methods. The Mn doping of the polyoxotitanate significantly reduces the band gap, confirming the significance of transition metal doping in photocatalysis applications.

We applied lateral magnetic tweezers to stretch duplex DNA molecules (Lambda DNA, 48,502 bp) in order to monitor the homology searching step by RecA nucleoprotein filaments at the single-molecule level. From individual searching events, the diffusion coefficient of the RecA nucleoprotein filament is determined to be ∼ 0.5-1 μm²/s. The nearly salt-independence of the diffusion coefficients of RecA nucleoprotein filaments implies that our observed RecA searching events were mainly carried out by the one-dimensional sliding mode.

Highly dispersed palladium nanoparticles were prepared by using aqueous extract of Astraglmanna, a non-toxic and eco-friendly material, without extra surfactant, capping agent, and template. The palladium nanoparticles were characterized using UV–Vis spectroscopy, (SEM-EDX), (FTIR), (DLS) and (XRD) analysis. The obtained results confirmed The presence of well dispersed nano-scale palladium particles ranging from 5-25 nm.

A novel Silicate nanotubes (SNTs) modified glass carbon (GC) electrode was prepared and used to study the electrochemcial behavior of phenylephrine (PHE). The enhanced electrochemical response of PHE at SNTs modified electrode was observed as compared with bare GC electrode. Our present study may provide an alternative way for the application to the electrochemical sensors.

Multi-walled carbon nanotubes decorated with Pd_xCo_y nanoparticles were fabricated by a simple pyrolysis process using ILs as the solvent. Results show that the Pd_xCo_y nanoparticles were uniformly dispersed on MWCNTs. And the onset potential was ∼90 mV lower and the peak current was about four times higher for ethanol oxidation for Pd₃Co_1.5/MWCNTs compared to those of Pd₃Co₁/MWCNTs.

Efficient method for direct preparation of 14–aryl–14–H–dibenzo[a,j]xanthenes through condensation of β–naphthol with various aromatic aldehydes in the presence of the catalytic amount of [H—NMP]⁺[HSO₄]⁻ under microwave irradiation was described. This method has the advantages such as; very easy reaction workup, absolute separation of catalyst from the reaction mixture and smooth recyclability of catalyst.

Two dimensional XRD patterns of Cyrtophora dragline during water absorption (right) and desorption (left). The darkness of diffraction pattern indicates that water can improve crystal quality in dragline.

A systematic structural investigation of seven silver(I) trifluoroacetate complexes containing ethynylphenyl ligands bearing ethynyl and isocyano substituents at variable positions has been carried out. It is established that the isocyano carbon atom, which bears a formal negative charge, only functions in the monodentate coordination mode in a silver-rich environment during directing the construction of multi-dimensional organosilver(I) networks.

Solid-state ¹³C single-pulse excitation NMR spectroscopy provides a direct and analytical tool to study the various tissues of Phalaenopsis in different growth and spiking induction periods at the molecular level.

The micro channel fabrication procedure was new, simple and inexpensive. The competitive assay based myoglobin detection on flow channel was reported using micro particles. The channel provides a protected liquid environment in which the handling of myoglobin in their natural state and specifically interact with anti myoglobin/magnetic hybrid particles. Due to effective magnetic separation, the method can detect real samples with in 30 min.

Reactions of CpRu(PPh₃)₂Cl with the o-enynyl phenols 6 containing various substituents on the aromatic ring yield the cyclic oxocarbene complexes 7. Deprotonation of 7 gives 8. Addition of various substituents at Cβ of 8 can be readily achieved by alkyl iodides. For the chromane ring derivatives 11, ring closing metathesis reaction of the two allyl groups yields product 12 with a tricyclic ligand.

In the specular reflectivity curve of superlattice of (YIG(1)/GGG(1))₁₂ on GGG substrate, the intensity of second harmonics is not asymmetric which indicates the thickness of YIG is 0.15 nm thicker. The off-specular longitudinal diffuse scattering (lower curve) shows the lateral layer height-height correlation is not perfectly grown conformationally, while the Bragg sheet can be clearly seen indicates good correlation of height fluctuation in the superperiod layers.

The PBNPs film has been chemically self assembled on electrochemically reduced graphene oxide modified GCE and used to detection of H₂O₂ in acidic media. The PBNPs|RGO film holds the promise for applications in various fields including bioelectronics devices, electrochromic displays, nonenzymatic sensor, and biofuel cells.

A novel 8-hydroxyquinoline functionalized PEG-1000 bridged dicationic ionic liquid ([HQ-PEG₁₀₀₀-DIL][BF₄]) was synthesized and used as an efficiently recyclable ligand for copper-catalyzed N-arylation of nitrogen-containing heterocycles.

Well-ordered mesoporous silicas MCM-48 and Al-MCM-48 with Ia3d bicontinuous and gyroidal cubic structure have been successfully synthesized within 24 hours via ultrasonic assisted hydrothermal approach under basic conditions using Gemini surfactant GEM 16-12-16 as the structure-directing agent. The use of ultrasonic irradiation has reduced the total synthesis time significantly compared to the conventional hydrothermal process that takes at least 7 days to prepare MCM-48.

This is the first report on the simultaneous determination of the baicalin and forsythin in Shuanghuanglian oral liquid by HPLC/DAD and LC-ESI-MS. The developed method was found to be simple, sensitive and accurate. It provided a reliable quality control method for Shuanghuanglian oral liquid.

A chemiluminescence phenomenon was observed when gossypol was injected into a reaction mixture of N-bromosuccinimide and alkaline dichlorofluorescein. Based on this phenomenon, a rapid and sensitive method for the determination of gossypol was established. The method has been applied to the determination of gossypol in cottonseed, cottonseed oil, pharmaceutical and biological fluids with satisfactory results.

A new microextraction technique using I-MWCNT in a commercial hollow fiber for liquid phase microextraction combined with LC-MS/MS for detecting diuretics in urine was developed and demonstrated in this study. This method is recommended for the determination of trace diuretics in urine samples due to its elegance, simplicity and high sensitivity, even in the presence of high levels of interfering compounds.

An efficient and sensitive analytical method based on molecularly imprinted solid-phase extraction and reverse-phase ultrasound-assisted dispersive liquid–liquid microextraction coupled with LC–MS/MS detection was developed and validated for the analysis of urinary 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL), a tobacco-specific nitrosamine metabolite.

For combustion of mosquito coils, the mass of BTEX extracted by 100 μm-PDMS SPME fiber were lower than those of all self-designed needle trap samplers (NTS). Comparison of all mesh samplers showed that the NTS packed with 100–120 mesh DVB adsorbed most BTEX, that is, 90–120 ng TEX and 50 ng benzene.

An electrochemical sensor, based on graphene-Nafion composite film modified GCE, was developed and used for detection of dihydromyricetin.

Synopsis activity-based probes 2-5 featuring a reactive fluorosulfonylbenzoyl moiety on an adenosine framework were prepared and evaluated for their labeling performance toward protein kinases.

A di-ruthenium complex containing an anthyridine-based ligand has been prepared and characterized. This complex appears to be catalytically active on α-cyanation of tertiary arylamines with sodium cyanide in the presence of oxidant.

The unusual high thermally-stable supramolecular entity of a nickel(II) histidine compound, [Ni(L-his)₂]×H₂O, was observed to show dynamic reversible de-/re-hydration property.

A few kinds of novel Schiff base complexes have been prepared by three component reaction of the substituted hydroxyacetophenone with several aliphatic diamines and transition metals such as; Ni(II), Zn(II) and UO₂(II) under mild reaction conditions. The products have been afforded with excellent yields and appropriate reaction times.

A series of novel cyclic and V-shaped cuprous clusters, (HNEt₃)₂ [Cu₆(bmsapy)₄] (1), [Cu₈(banlny)₄] (2) and [Cu₆(ansny)₄Cl] (CF₃SO₃) (3), were synthesized. Compounds (1) and (2) possess a similar cyclic metal structural arrangement, and the metallic arrangement of compound (2) is as in (1) with an insertion of a pair of ligand-unbridged Cu(I) atoms. Compounds (1) and (2) both have unusual ligand-unbridged Cu(I)-Cu(I) separations. In absorption spectra, compound (2) displayed red shifts from (1) due to the increase in nuclearity and the number of the aromatic rings in ligands

An excellent agreement between the experimental and theoretical deformation density, laplacian distribution of electron density and BCP properties is found for the intra-molecular covalent bonds and inter-molecular hydrogen bonds in Hdpa molecule.

A mild and efficient method for the one-pot synthesis of substituted dihydropyrrol-2-one derivatives is described via four-component domino reaction of amines, dialkyl acetylenedicarboxyaltes and formaldehyde in the presence of 1-Methyl-2-oxopyrrolidinium Hydrogen Sulfate ([Hpyro][HSO₄]) as ionic liquid catalyst. This facile approach proceeded smoothly in good to high yields and pure products are separated from the reaction mixture by simple filtration.

In this work, a novel non-enzymatic glucose sensor based on nickel hydroxide and intercalated graphene with ionic liquid nanocomposite modified glass carbon electrode was fabricated by an electrochemical method and its electrochemical behaviors were studied. This work may be expected to develop an excellent electrochemical sensing platform for G-IL as a catalysis carrier.

The catalytic efficiency of NH₄H₂PO₄/MCM-48 and NH₄H₂PO₄/MCM-41 was compared in the solvent free synthesis of 3,4-dihydropyrimidin-2(1H)-ones through one-pot three-component condensation of ethyl acetoacetate, an aryl aldehyde and urea. Different reaction parameters including catalytic efficacy, solvent effect, and urea concentration are considered.

Near the end stage of the zipper formation, the NMR data show that there is a layer of water molecules trapped in between the two closely stacking β-sheet layers. The zipper formation is completed upon the depletion of the water molecules between the interdigitated β-sheet layers.

Toluenes underwent base-promoted selective benzylic carbon-hydrogen bond activation (CHA) with rhodium porphyrin chlorides (Rh(por)Cl) to give benzylic rhodium porphyrins. Extensive studies has been undertaken to identify the synthetic scopes and gain further mechanistic understanding of the base-promoted benzylic CHA. Evidences support the parallel benzylic CHA with Rh₂(por)₂ ­and Rh(por)H, and the former is the more reactive intermediate.

A novel method to prepare monolithic MIP fibers for SPME is developed using silica capillaries as molds. With the help of microwave irradiation, polymerization was carried out in 5.5 min using olivetol as a template molecular, α-methacrylic acid as a functional monomer and ethylene dimethacrylate as a crosslinker, toluene and dodecanol as the binary porgens. The monolithic MIP fibers were obtained after silica being etched away with a controlled length and successfully applied to the SPME of olivetol in real samples.

A theoretical study on sodalite cage ZnO12 nanocluster with Density Functional Theory using B3LYP and B3PW91 hybrid and M06 meta-hybrid functionals in combination with 6-31+G*, Lanl2dz and SDD basis sets. Within this work a fresh approach is used to treat a transition metal ZnO nanostructure obtaining comparable results probing acceptable quality as an alternative to hybrid functional methods.

Non-toxic CuInS₂ (CIS) I–III–VI-type quantum dots (QDs) and CIS/ZnS were synthesized by the facile solvothermal method. Red-emitting CIS/ZnS QDs-assisted Y₃Al₅O₁₂:Ce³⁺ phosphor-based white LED effectively improve color rendering index (Ra = 86), indicating non-toxic CIS/ZnS QDs are promising candidates for application in white LEDs.

A 2-D grid copper(II) complex [Cu(μ₃-H₂dpzpda)(N₃)]_n(ClO₄)_n has been synthesized and structurally characterized, and magnetic studies indicate the presence of very weak antiferromagneic coupling between copper(II) ions.

This is the first study on developing six alkali transition metal phosphites as potential candidates of cathode materials grown from molten boric acid. Compounds 1 and 2 are featured with high theoretical capacitance values up to 117 and 123 mAh/g, respectively. Compounds 3 to 6 are layered and strongly related in topology.

Synthesis and characterization for series of symmetrical 1,3-dialkylimidazolium salts and their 1-alkylimidazole precursors are presented. The LC properties of symmetrical 1,3-dialkyl ImILCs with different counter anions (Cl⁻, Br⁻, I⁻, PF₆⁻) are described. A smectic A mesophase, typical for rod-like imidazolium salts, is assigned.

Direct acylation of 3,6-di-tert-butyl-9H-carbazole yields N-acetyl-carbazole and 1,8-diacetyl-carbazole as major products along with the products related to dealkylation.

Fumed silica is a useful support for amines on CO₂ capture. The amine efficiency (CO₂/N) of APS grafted on fumed silica reaches to 0.5. TEPA loaded on fumed silica possesses high stability and efficiency for CO₂ capture. The order of thermal stability of amines on silicas is C₃H₆NH₃⁺>C₃H₆NH₂>TEPA. The stability of amines depends on their interaction to supports.

A 3D supramolecular architecture is constructed by the subtle combination of π···π stacking and hydrogen-bonding interactions among the 1D zigzag chains of [Fe(bpno)₃(NCS)₃]

Four isomorphous MOFs, Ln₄(TDC)₆(DMF)₄(H₂O)₂, where Ln = Nd (1), Sm (2), Eu (3), Gd (4), TDC²⁻ = thiophene-2,5-dicarboxylate, were synthesized and characterized. They adopt 3D frameworks featuring rhomboidal channels, inside which coordinated DMF solvent molecules are located. TGA studies suggest solvent molecules can be removed about ca. 340 °C. Photoluminescence studies indicate TDC²⁻ ligand shows excellent antenna effect for the europium(III) MOF (3).

PdCl₂(NH₃)₂/cationic 2,2′-bipyridyl system-catalyzed hydroxycarbonylation of aryl iodides in the presence of CO in water leads to the formation of aromatic carboxylic acids in high yields. The residual aqueous solution is able to be reused for several cycles with only a slight decrease in activity.

The identity of N-substituted alkyls in aluminum amine biphenolate complexes was found to have substantial impacts on both polymerization rates and molecular weight distributions in ring-opening polymerization catalysis.

The reactions of iron acyl chalcogenide clusters [Fe₃(CO)₉{μ₃-η²:η¹:η³-C(O)CHC(S)CH₂}]⁻ and [(μ₃-E)Fe₃(CO)₉(μ₃-η¹:η¹:η³-C(O)C(H)CCH₂)]⁻ (E = Se, Te) with a series of electrophiles have been systematically demonstrated, in which novel SFe₃- or SeFe₂-based Fischer-type acyloxy carbene complexes [Fe₃(CO)₉{μ₃-η²:η⁴:η¹-C(OCOCH₃)C(H)C(S)CH₃}] and [Fe₂(CO)₆{μ-η²:η³-C(OCOCH₃)C(H)C(Se)CH₂}] were obtained. The nature, formation, and bonding properties of these complexes were discussed with the aid of DFT calculations as well.

Ni(II)-chalcogenolate/chalcogenol complexes with the thiol in the secondary coordination sphere were reported. The rotatable C-S and C-C bonds of [N(CH₂CH₂S)₂(CH₂CH₂SH)]²⁻ release intramolecular [Ni-S···H-S] and [Ni···H-S] interaction.

Synopsis The synthesized TiO₂ NPs have unique morphology, narrow size distribution (13–18 nm), high crystallization (anatase phase), and high surface area (86.02 m²·g⁻¹), characteristics that improve dye absorption and electron transport, which in turn are beneficial for the application of these NPs in DSSCs. Under AM1.5G solar illumination at 100 mW·cm², the as-prepared TiO₂ device exhibited an overall conversion efficiency (η) of 2.11% using oligo-PEGDME electrolyte.