Synthesis and modification strategies of g-C_(3)N_(4) nanosheets for photocatalytic applications

Graphitic carbon nitride nanosheets(CNNs)become the most promising member in the carbon nitride family benefitted from their two-dimensional structural features.Recently,great endeavors have been made in the synthesis and modification of CNNs to improve their photocatalytic properties,and many exciting progresses have been gained.In order to elucidate the fundamentals of CNNs based catalysts and provide the insights into rational design of photocatalysis system,we describe recent progress made in CNNs preparation strategies and their applications in this review.Firstly,the physicochemical properties of CNNs are briefly introduced.Secondly,the synthesis approaches of CNNs are reviewed,including top-down stripping strategies(thermal,gas,liquid,and composite stripping)and bottom-up precursor molecules design strategies(solvothermal,template,and supramolecular self-assembly method).Subsequently,the modification strategies based on CNNs in recent years are discussed,including crystal structure design,doping,surface functionalization,constructing 2D heterojunction,and anchoring single-atom.Then the multifunctional applications of g-C_(3)N_(4) nanosheet based materials in photocatalysis including H_(2) evolution,O_(2) evolution,overall water splitting,H_(2)O_(2) production,CO_(2) reduction,N_(2) fixation,pollutant removal,organic synthesis,and sensing are highlighted.Finally,the opportunities and challenges for the development of high-performance CNNs photocatalytic systems are also prospected.

Microwave-assisted Synthesis of Al_(4)SiC_(4) and Its Effect on Properties of MgO-C Refractories

Al_(4)SiC_(4) was synthesized from Al powder, silicon carbide, and graphite by microwave sintering, and characterized by XRD and SEM. Then the synthesized material was added to the magnesia carbon refractory brick to study its effect on the oxidation resistance, apparent porosity, bulk density, elastic modulus, and modulus of rupture. It is found that Al_(4)SiC_(4) can be synthesized by microwave sintering at 1 300 ℃ and the addition of Al_(4)SiC_(4)-containing material as an antioxidant can enhance the oxidation resistance of the magnesia carbon refractory brick.

Aluminum and Activated Alumina Powder Additions on Microwave Synthesis of Al_(4)SiC_(4)

Aiming at improving the properties of magnesia carbon materials,silicon aluminum carbide(Al_(4)SiC_(4))containing materials were prepared using industrial aluminum powder,silicon carbide powder,and graphite as raw materials,and activated alumina powder as an additive,mixing thoroughly,pressing into cylinders and then firing at 1200℃for 30 min in a carbon embedded atmosphere by the microwave method.The effects of the aluminum powder addition(20%and 24%,by mass)and activated alumina powder addition(0,3%,5%and 7%,by mass)on the microwave synthesis of Al_(4)SiC_(4) as well as the effect of the obtained Al_(4)SiC_(4) containing material on the properties of magnesia carbon bricks were studied.The results show that:compared with the samples with 20%aluminum powder,those with 24%aluminum powder generate more Al_(4)SiC_(4).With the activated alumina powder addition increasing from 0 to 7%,the amount of Al_(4)SiC_(4) generated increases first and then decreases.Compared with the sample without activated alumina powder,the samples with activated alumina powder show lower bulk density and higher apparent porosity.With the activated alumina powder addition increasing from 3%to 7%,the bulk density of the samples increases first and then decreases,while the apparent porosity of the samples shows an opposite trend.The optimal additions are 24%aluminum powder and 5%activated alumina powder,and Al_(4)SiC_(4) synthesized in this sample has a hexagonal plate structure.With the synthesized Al_(4)SiC_(4) containing material added,the magnesia carbon brick has slightly increased cold modulus of rupture,basically the same modulus of elasticity and improved oxidation resistance.

A Convenient Synthesis of Trans and Cis-3, 4′, 5-trihydroxystilbene

Aim To synthesize trans and cis-3, 4′, 5-trihydroxystilbene by a new convenient route. Methods The reaction of 3, 5-dimethoxybenzaldehyde （3） and 4-methoxy phenylacetonitrile （4） formed the stilbene skeleton. After hydrolyzation, decarboxylation, and demethylation, we obtained trans-3, 4′, 5-trihydroxystilbene （resveratrol）, which can be converted to its cis-isomer by photochemical isomerization. Results Starting from 3 and 4, trans and cis-3, 4′, 5-trihydroxystilbene were synthesized, respectively. Conclusion A facile method for the synthesis of trans and cis-hydroxystilbenes from readily available materials was established.

Framework-solvent interactional mechanism and effect of NMP/DMF on solvothermal synthesis of [Zn_4O(BDC)_3]_8

In order to explore the effect mechanism of solvent on the synthesis of the metal organic framework materials, the microscopic interaction between solvent and framework and the effects of N,N-dimethyl-formamide(DMF) or N-methyl- 2-pyrrolidone(NMP) on solvothermal synthesis of [Zn4O(BDC)3]8 were investigated through a combined DFT and experimental study. XRD and SEM showed that the absorbability of NMP in the pore of [Zn4O(BDC)3]8 was weaker than that of DMF. The thermal decomposition temperature of [Zn4O(BDC)3]8 synthesized in DMF was higher than that in NMP according to TG and FT-IR. In addition, the nitrogen sorption isotherms indicated that NMP improved gas sorption property of [Zn4O(BDC)3]8. The COSMO optimized calculations indicated that the total energy of Zn4O(BDC)3 in NMP was higher than that in DMF, and compared with non-solvent system, the charge of zinc atoms decreased and the charge value was the smallest in NMP. Furthermore, the interaction of DMF, NMP or DEF in [Zn4O(BDC)3]8 crystal model was calculated by DFT method. The results suggested that NMP should be easier to be removed from pore of materials than DMF from the point of view of energy state. It can be concluded that NMP was a favorable solvent to synthesize [Zn4O(BDC)3]8 and the microscopic mechanism was that the binding force between Zn4O(BDC)3 and NMP molecule was weaker than DMF.

Novel process for large scale synthesis of N-(4-hydroxyphenyl) retinamide

A method to synthesize anticancer drug N-（ 4- hydroxyphenyl） retinamide （4-HPR）on a large scale is described. It consists of the preferred steps of reacting all-trans retinoic acid with thionyl chloride to form retinoyl chloride and then reacting with triethylamine to generate retinoyl ammonium salt which in turn is reacted with p-aminophenol to eventually produce 4-HPR. This process can overcome many scale-up challenges that exist in the methods reported in the literature and provide an easy, mild and high yield route for large scale synthesis of 4-HPR. Moreover, the effects of the molar ratios of the reagents on the yield are examined. The best molar ratios are a 2.0 molar equivalence of thionyl chloride and a 3.0 molar equivalence of paminophenol to retinoic acid, and the total yield is 80. 7%.

Synthesis and plant-growth regulatory activities of novel imine derivatives containing 1H-1,2,4-triazole and thiazole rings

Eleven new imine derivatives 6 containing 1H-1,2,4-triazole and thiazole rings were synthesized by the condensation of 5-((1H- 1,2,4-triazol-1-yl)methyl)-4-tert-butylthiazol-2-amine with various substituted benzaldehydes.The structures of the title compounds were characterized by ~1H NMR,MS and elemental analysis.The plant-growth regulatory activities of these compounds were evaluated.The primary bioassay results indicated that these target compounds exhibited promising plant-growth regulatory activities.

Synthesis and Crystal Structure of 2(1-Phenyl-3-methyl-5-chloro-1H-pyrazol- 4-yl)-3-(1-naphthoylamido)-4-thiazolidinone

The crystal structure of 2(1-phenyl-3-methyl-5-chloro-1H-pyrazol-4-yl)-3-(1- naphthoylamido)-4-thiazolidinone (C24H19ClN4O2S, Mr = 462.94) has been determined by single- crystal X-ray diffraction method. The crystal belongs to monoclinic, space group P21/c with a = 11.623(5), b = 11.579(5), c = 16.619(7) ? b = 90.112(8), V = 2237(2) 3, Z = 4, Dc = 1.375 g/cm3, m = 0.294 mm-1, F(000) = 960, R = 0.0492 and wR = 0.0768 for 3932 unique reflections with 1897 observed ones (I > 2s(I)). X-ray analysis reveals that there exist both intra-and intermolecular hydrogen bonds in the crystal lattice.

A facile synthesis of 2,4,6-trichloroborazine from boron trichloride-dimethylsulfide complex and ammonium chloride

2,4,6-Trichloroborazine has been recognized as a desirable monomer for the preparation of high-performance boron nitride fibers through polymer derived ceramics route.So a high yield and facile synthesis of 2,4,6-trichloroborazine is essential in practice. Using boron trichloride-dimethylsulfide complex((CH_3)_2S·BCl_3) and ammonium chloride(NH_4Cl) as starting materials and toluene(C_6H_5CH_3) as solvent,the synthesis of 2,4,6-trichloroborazine to give high yield is reported.

Synthesis,Crystal Structure and Biological Activity of N-(2,6-Difluorobenzoyl)-N'-[5-(4-trifluoromethyl-phenyl)-1,3,4-thiadiazol-2-yl]ure

The title compound N-（2,6-difluorobenzoyl）-N＇-[5-（4-trifluoromethylphenyl）-1,3,4-thiadiazol-2-yl]urea（C17H9F5N4O2S,Mr = 428.34） has been synthesized by the reaction of 2-amino-5-（4-trifluoromethylphenyl）-1,3,4-thiadiazole with 2,6-difluorobenzoyl isocyanate,and its crystal structure was determined by single-crystal X-ray diffraction.The crystal belongs to monoclinic,space group P21/n with a = 10.7316（13）,b = 10.5617（13）,c = 16.037（2） ,β = 106.408（2）°,V = 1743.6（4） 3,Z = 4,Dc = 1.632 g/cm3,μ = 0.260 mm-1,F（000） = 864,the final R = 0.0599 and wR = 0.1420 for 3467 observed reflections with I〉 2σ（I）.The urea group,which adopts a planar configuration mediated by the intramolecular N-H...O hydrogen bond,is nearly coplanar with the thiadiazole and 4-trifluoromethylbenzene rings.The title compound was found to exhibit good fungicidal activity against Rhizoctonia solani and Botrytis cinerea.

Synthesis and Crystal Structure of Calix[4]arene Bearing a 1,8-Bis(propoxy)anthracene-9,10-dione

The title complex （C50H44C14O8） was synthesized and structurally determined by single-crystal X-ray diffraction method. It crystallizes in monoclinic, space group P21/n with a = 19.7768（4）, b =10.2085（2）, c = 21.2721（4）A,β= 97.153（1）°, V = 4261.23（14）A^3, Z = 4, Mr = 914.65, F（000） = 1904, Dc = 1.426 g/cm^3,μ = 0.336, the final R = 0.0550 and wR = 0.1647. The compound was structurally characterized by IR and ^1H NMR. The molecules are stacked through C-H...π interactions and intermolecular C-H...O hydrogen bonds.

A new isochroman-4-one derivative from the peel of Musa sapientum L.and its total synthesis

A new isochroman-4-one, 7,8-dihydroxy-3-methylisochroman-4-one was isolated from water soluble fraction of Musa sapientum L. Its structure was determined by spectroscopic evidences and its total synthesis has also been reported. The compound showed potent antihypertensive activity.

First total synthesis of (±)-puyanin and (±)-4'-O-methylbonannione

A facile approach for the first total synthesis of two naturally occurring geranylated flavonoids,（±）-puyanin 1 and（±）-4＇-O- methylbonannione 2 has been obtained with total yield 27%and 21%,respectively.The key steps were regioselective cyclization of geranylated trihydroxychalcone and regioselective geranylation of 2,4,6-trihydroxyacetophenone.

Synthesis and biological evaluation of ethyl 6-alkoxy-7-phenyl-4-hydroxy-3-quinolinecarboxylates against Eimeria tenella

A series of ethyl 6-alkoxy-7-phenyl-4-hydroxy-3-quinolinecarboxylates were designed and synthesized.Their structures were confirmed by ~1H NMR,^(13)C NMR,IR and HRMS.The biological activities were primarily evaluated against Eimeria tenella according to Anticoccidial Index(ACI) method in vivo.The results showed that compounds 5e,5f and 5i exhibited anticoccidial activities against E.tenella at 27 mg kg^(-1).

Microwave synthesis of Li_2FeSiO_4 cathode materials for lithium-ion batteries

A novel synthetic method of microwave processing to prepare Li2FeSiO4 cathode materials is adopted. The Li2FeSiO4 cathode material is prepared by mechanical ball-milling and subsequent microwave processing. Olivin-type Li2FeSiO4 sample with uniform and fine particle sizes is successfully and fast synthesized by microwave heating at 700 ℃ in 12 rain. And the obtained Li2FeSiO4 materials show better electrochemical performance and microstructure than those of Li2FeSiO4 sample by the conventional solidstate reaction. ？2009 Yan Bing Cao. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.

One-step synthesis of Pt@ZIF-8 catalyst for the selective hydrogenation of 1,4-butynediol to 1,4-butenediol

A catalyst consisting of platinum nanoparticles on a ZIF-8 support（Pt@ZIF-8） was synthesized in a straightforward one-step procedure,by adding a nanostructured platinum sol during the formation of ZIF-8 at room temperature.Pt@ZIF-8 was highly porous and well crystallized.The Pt nanoparticles were well dispersed within the ZIF-8 support.In the hydrogenation of 1,4-butynediol,Pt@ZIF-8 exhibited high activity,excellent selectivity for 1,4-butenediol of greater than 94%,and reusability.The Pt@ZIF-8 catalyst did not require further additives.The favorable catalytic performance was attributed primarily to the modification of the ZIF-8 support by the platinum nanoparticles.

Synthesis and Structural Analysis of LDH-SO4-CO3 Whisker

High-quality LDH-SO4-CO3 whiskers were synthesized via liquid precipitation method using MgSO4·7 H2 O and Al2(SO4)3·18 H2O as precursors and Na2CO3-NaHCO3 buffer solution as precipitant. The influence of buffer solution concentration on the characteristics of the samples was investigated. The asgrown whiskers were characterized by X-ray diffraction, transmission electron microscopy, and BrunauerEmmett-Teller N2 specific surface area measurements. The results show that the buffer solution concentration has significant impact on whiskers with intercalated structure. The LDH-SO4-CO3 whiskers with well-defined geometry, distinct intercalated structure, decent quality, and excellent dispersing capability can be obtained under the following conditions: buffer solution volume ratio of 45%, reaction temperature of 83°C, and reaction time of 182 h. The obtained whiskers are well-crystallized and exhibit homogeneous morphology consisting of fiber bars.

Synthesis and Photoluminescence of a Novel Iridium Complex (BuPhOXD)_2Ir(acac) with Unit of 1, 3, 4-Oxadiazole

A novel cyclometalated iridium complex with 1, 3, 4-oxadiazole moiety was synthesizedand characterized. Its UV and photoluminescent properties were studied. The strong UVabsorption intensity around 462 nm attributed to spin-forbidden triplet metal–ligand charge transferband and photoluminescence at 518 nm were observed. This indicated that achieved iridiumcomplex could be used as an efficient electrophosphorescent material.

New Facile Synthesis of 2-Aryloxy-5-(2-furfurylidene)- 4H-imidazolin-4-ones

Novel 2-aryloxy-5-(2-furfurylidene)-4H-imidazolin-4-ones 6 were synthesized by aza-Wittig reaction of vinyliminophosphorane 4 with phenyl isocyanate and subsequent condensation with Various substituted phenols in the presence of catalytic amount of potassium carbonate. The products are confirmed by H-1 NMR, MS, IR and elementary analysis.

Synthesis and Crystal Structure of 2-Ethoxy-3-n-butyl-benzofuro [2,3-d]pyrimidin-4(3H)-one

The crystal structure of the new title compound 2-ethoxy-3-n-butyl- benzofuro[2,3d]pyrimidin-4（3H）-one （C16H18N2O3, Mr = 286.32） has been prepared and determined by singlecrystal X-ray diffraction. The crystal is of monoclinic, space group P21/c with a = 13.7167（14）, b = 13.113（1）, c = 8.378（1） A, β = 98.992（2）^o, V = 1488.4（3） A^3, Z = 4, Dc = 1.278, F（000） = 608, μ = 0.089 mm^-1, MoKa radiation （2 = 0.71073）, R = 0.0498, wR = 0.1238 for 2336 observed reflections with I 〉 2σ（I）. X-ray diffraction analysis reveals that all ring atoms in the benzo[4, 5]furo [2,3-d] pyrimi- dinone moieties are almost coplanar.