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In order to obtain a flame-retardant epoxy resin (EP) composite with good flame retardancy, ammonium polyphosphate (APP) was applied to EP in combination with hexa-(4-(9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-sulfide)-hydroxymethylphenoxy)cyclotriphosphazene (HAP-DOPS). The experimental results showed that the flame retardancy of EP composite can be improved effectively when HAP-DOPS was compounded with APP and added to EP. Under the premise condition of the phosphorus content in the system was 1.6% and m HAP-DOPS: m APP = 1.5:1, the LOI value reached 30.0% and the vertical burning test reached UL94 V-0 rating, at which point the flame retardancy of the compound system was optimal. Compared with HAP-DOPS/EP, the thermal stability of HAP-DOPS/APP/EP was improved, and the char residues were increased; the total heat release (THR) was decreased by 40.66%, and the total smoke release (TSR) was decreased by 34.13%. And the flexural strength and tensile strength were increased by 32.52% and 14.46%, respectively. The study of flame-retardant mechanism showed that the addition of HAP-DOPS/APP to EP can promote the formation of phosphorus-rich char residues, which mainly played a flame-retardant role in the condensed phase and in the gaseous phase by releasing noncombustible NH3.

Facile preparation of functional hydrogel materials for environmental catalysis is a hot research topic of soft materials science and green catalysis. In this study, a carboxylcellulose hydrogel confined Fe3O4 nanoparticles composite catalyst (Fe3O4@CHC) with magnetic recyclability has been synthesized by taking the advantages of the newly developed cellulose solution in tetramethyl guanidine/DMSO/CO2 through in situ acylation using mixed cyclic anhydrides and ion exchange reaction. The achieved Fe3O4@CHC hydrogel catalyst was shown to be an more efficient and better Fenton-like catalyst for decomposition of the organic dye rhodamine B (RhB) in the presence of hydrogen peroxide, with almost complete decomposition occurring within 180 min, in comparison with Fe3O4@cellulose hydrogel (CH) with excellent recyclability. This work provided a facile strategy for the preparation of hydrogel-based functional composite green catalytic materials, which has potential applications in green catalysis.

Facile dissolution of silk fibroin by using sustainable solvents is the first challenge to be overcome towards its value-added utilization. In this study, sustainable protic ionic liquids (PILs), which were prepared by a simple solventless neutralization reaction of 1,5-diazabicyclo [4.3.0]-5-nonene (DBN) and biomass-derived levulinic acid (Lev), were identified to have good solubility to silk fibroin at mild conditions. Furthermore, the co-dissolution of silk fibroin and cellulose was investigated, and the solute-solvent interaction was elucidated by 13C NMR spectroscopy. The findings demonstrated that the strong hydrogen bonding forming ability of [DBNH][Lev] PILs partially arose from the potential keto–enol tautomerism of levulinate and endowed it with desirable solubility of cellulose and silk fibroin. The rheological properties of cellulose/silk fibroin solutions were systematically studied, indicating that the mass feed ratio of cellulose/silk fibroin significantly affected the apparent viscosity, overlap concentration (c*), activation energy, storage modulus and loss modulus. The interaction and aggregation between cellulose and silk fibroin were further elucidated by dynamic light scattering (DLS). The solution properties provided great opportunities for regenerated cellulose/silk fibroin composited membranes and fiber preparation, and a series of composite membranes were facilely prepared by sol–gel transition using ethanol as a coagulation bath. Various techniques were employed to elucidate the corrections among the structural, morphological, thermal and mechanical properties of the composited membranes and fibers, including infrared spectroscopy (FTIR), X-ray diffraction (XRD), thermogravimetric analysis (TGA), scanning electron microscopy (SEM) and tensile tests. It was found that composited membranes (C50S50) had the best mechanical properties, with a tensile strength of 50 MPa and oxygen permeability of 0.0055 cm3 μm (m2 day atm)−1. Moreover, the composited fiber (C80S20) has desirable tensile strength of 152 MPa and an elongation at break of up to 12.8%.

Facile preparation of functional hydrogel materials for environmental catalysis is a hot research topic of soft materials science and green catalysis. In this study, a carboxylcellulose hydrogel confined Fe

Differential scanning calorimetry measurements performed in the temperature range of 253–393 K for CF2O linkage liquid crystals reveal existence and stability of the phase transitions. Then, we report molar heat capacities for three difluoromethyleneoxy liquid crystalline compounds measured by the heat-pulse relaxation method within the temperature range from 1.9 to 300 K. The heat capacities of these three compounds increase with the temperature increasing and no thermal anomalies have been found in the whole temperature region. The experimental data have been fitted to a function of temperature with a series of theoretical and empirical models for the proper temperature ranges. Standard thermodynamic properties of these three fluorinated liquid crystals are evaluated from the experimental heat capacity temperature dependencies. The standard molar heat capacities of 3-CB(F,F)XB(F,F)-F, 2-BB(F,F)XB(F,F)-F and 2-BB(F)B(F,F)XB(F,F)-F at 298.15 K and 0.1 MPa have been determined to be $$ C_{{{\text{p}},{\text{m}}}}^{\text{o}} $$ = (560.84 ± 5.61) and (464.41 ± 4.64) and (560.58 ± 5.61) J K−1 mol−1, respectively.

The stabilities and the phase transition sequences of two ethylene-bridge fluorinated liquid crystals have been examined using the differential scanning calorimeter; and the repeatability and reliability for these phase transitions also have been verified. Furthermore, we report molar heat capacities of these two fluorinated liquid crystals measured using a Quantum Design physical properties measurement system with specific heat option within the temperature range from 1.9 to 300 K. The heat capacities of these two compounds increase with the temperature increasing, and no thermal anomalies have been found in the entire temperature region; and also the heat capacity values of 5-BB2B-F are larger than those of 3-BB2B-F due to the molecular weight difference even though they are homologous. The experimental data have been fitted to a function of T with a series of theoretical and empirical models for the proper temperature ranges. Thermodynamic function values \(C_{\text{p,m}}^{0} ,\Delta_{ 0}^{{\text{T}}} S_{\text{m}}^{\text{o}}\) and \(\Delta_{ 0}^{\text{T}} H_{\text{m}}^{\text{o}}\) at T = (0.5–300) K have been calculated based on these fitting results. The standard molar heat capacities, entropies and enthalpies of 3-BB2B-F and 5-BB2B-F at 298.15 K and 0.1 MPa have been determined to be \(C_{\text{p,m}}^{\text{o}}\) = (450.02 ± 4.50) J K−1 mol−1 and (478.08 ± 4.78) J K−1 mol−1, \(S_{\text{m}}^{\text{o}}\) = (443.91 ± 4.44) J K−1 mol−1 and (486.85 ± 4.87) J K−1 mol−1 and \(H_{\text{m}}^{\text{o}}\) = (66.47 ± 0.66) kJ mol−1 and (72.66 ± 0.73) kJ mol−1, respectively.

A general visible light induced direct difluoromethylation of N-methacryloyl benzamides by using difluoromethyl sulfone was developed. In addition, photoredox-catalyzed trifluoromethylation of N-methacryloyl benzamides with trifluoromethyl sulfone via a similar radical process was also achieved. This method allows for an efficient and practical synthesis of a variety of CF2H/CF3-containing isoquinoline-1,3(2H,4H)-diones in moderate to good yields. The reaction features mild reaction conditions, operational simplicity, and a broad substrate scope.

We report the results of the study of thermodynamic properties for two difluorooxymethylene-bridged fluorinated liquid crystals. Isobaric heat capacities of the compounds were measured using a Quantum Design Physical Properties Measurement System with heat capacity measurement in the range of 1.9–300 K. Heat capacities of two compounds increased with the temperature increment, and no any thermal anomalies were observed in the whole temperature region, and also the heat capacity values of 5-CCXB(F,F)-F are larger than that of 3-CCXB(F,F)-F due to molecular weight difference even though they are homologs. Standard thermodynamic properties of the liquid crystals were evaluated from the experimental heat capacity temperature dependencies. From the heat capacity results, the standard molar entropies and enthalpies at 298.15 K were determined to be (657.32 ± 6.57), (741.81 ± 7.42) J K−1 mol−1 and (97.17 ± 0.97), (108.89 ± 1.09) kJ K−1 mol−1 for n-CCXB(F,F)-F (n = 3, 5), respectively. Finally, the phase transition sequences and thermodynamical stability of these two fluorinated liquid crystals were performed by differential scanning calorimetry measurements in the temperature range of 253–373 K.

Metal-organic frameworks (MOFs) have attracted a great deal of attention over the past two decades. Herein, we used a four-carboxylic acids linker, namely 3,3′,5,5′-azobenzene-tetracarboxylic acid (H4abtc), and adenine (ad) as the organic building blocks to form MOFs, not only because they are suitable to construct microporous frameworks, but also by reason of their multi-connectivity abilities. A microporous zinc(II) MOF material, [H2N(CH3)2]·[Zn4(abtc)2(ad)H2O)]·4DMF was successfully synthesized under solvothermal reactions. The resulting material demonstrates highly selective CO2 uptake over CH4.

The heat capacities of 6-chlorouracil and 5-chlorouracil isomers were measured using a Quantum Design physical properties measurement system (PPMS) based on a heat pulse relaxation method over the temperature range from (1.9 to 300) K, and the experimental data were fitted as a function of temperature using a series of theoretical and empirical models for the appropriate temperature ranges. The results of these fits were used to calculate thermodynamic function values, C p , m 0 , △ 0 T S m o , and △ 0 T H m o from T = (0.5 to 300) K. The standard molar heat capacities, entropies and enthalpies of 6-chlorouracil and 5-chlorouracil at 298.15 K and 0.1 MPa were determined to be C p , m o = (136.94 ± 1.37) J K −1 mol −1 and (137.95 ± 1.38) J K −1 mol −1 , S m o = (156.87 ± 1.57) J K −1 mol −1 and (154.97 ± 1.55) J K −1 mol −1 and H m o = (23.01 ± 0.23) kJ mol −1 and (23.07 ± 0.23) kJ mol −1 , respectively.

The heat capacities of three difluoromethyleneoxy liquid crystalline compounds (n-BB(F)B(F,F)XB(F,F)-F; n = 3, 4, 5) were measured using a quantum design physical properties measurement system (PPMS) based on a heat-pulse relaxation method in the temperature range from 1.9 to 300 K. The experimental results showed that the heat capacities of these three compounds increased with the temperature increment and none of the thermal anomalies were observed in the entire temperature region; and also the heat capacity values of n-BB(F)B(F,F)XB(F,F)-F (n = 3, 5) are larger than those of 4-BB(F)B(F,F)XB(F,F)-F due to the odd–even carbon effect below 21 K. The standard molar entropies at 298.15 K and 0.1 MPa were determined to be (631.14 ± 6.31), (650.21 ± 6.50), and (697.49 ± 6.97) J K−1 mol−1 for n-BB(F)B(F,F)XB(F,F)-F (n = 3, 4, 5), respectively.

A mild and efficient method for the synthesis of 6-difluoromethylenephosphonyl-phenanthridines through visible-light-promoted radical difluoromethylenephosphonation of 2-isocyanobiaryls with bromodifluoromethylphosphonate has been developed. The reaction allows the direct formation of Csp2 CF2PO(OEt)2 and C C bonds via a proposed tandem radical cyclization process.

A new Cd(ΙΙ) coordination polymer with 1,4-phenylenediacetic acid (H2PDA) and 1,4-bis(3-pyridylmethy)piperazine (BPMP) has been prepared by hydrothermal synthesis and characterized by single-crystal X-ray diffraction and IR. Complex{[Cd(PDA) (BPMP)]· 4 (H2O)}n (1) is triclinic, space group P–1 with a = 10.443 (5), b = 11.542 (5), c = 13.197 (5) A, α = 87.510 (5)°, β = 70.648 (5)°, γ = 85.711 (5)°, V = 1496.3 (11) A3, Z = 2, Mr = 648.99, Dc = 1.432g/cm3, F(000) = 664, and µ = 0.781 mm−1. The final refinement gave R = 0.0571 and wR = 0.0616 for 6184 reflections with I > 2σ(I). X-ray diffraction analysis reveals that the complex 1 displays three-dimensional structure with a pcu topological net.

The coordination polymers [Zn2(NDA)(HNDA)2(IPT)2]n (1) and [Mn(NDA)(IPT)]n (2) [H2NDA = naphthalene-1,4-dicarboxylic acid and IPT = 4′-(4-(1H-imidazol-1-yl)phenyl)-4,2′:6′,4′′-terpyridine] were synthesized under hydrothermal conditions and characterized by single-crystal X-ray diffraction. Complex 1 features a one-dimensional ladder-like chain, whereas complex 2 shows a three-dimensional CdS topology. The different coordination modes for organic ligands and topological nets for complexes 1 and 2 are mainly related with the metal ions.

A practical strategy has been described for the preparation of 6-trifluoroethyl-phenanthridine derivatives using a visible-light-promoted trifluoroethylation reaction of 2-isocyanobiaryl with trifluoroethyl iodide. These reactions could be carried out at room temperature in good to excellent chemical yields with good functional group tolerance.

A general visible light induced direct difluoromethylation of N-methacryloyl benzamides by using difluoromethyl sulfone was developed. In addition, photoredox-catalyzed trifluoromethylation of N-methacryloyl benzamides with trifluoromethyl sulfone via a similar radical process was also achieved. This method allows for an efficient and practical synthesis of a variety of CF

A simple and practical approach to oxindole derivatives via visible-light-photocatalyzed aryldifluoroacetylation of N-arylacrylamides with BrCF2CO2Et has been developed. This method provides convenient access to a variety of difluoroester-substituted oxindoles under mild conditions.

A practical and unified strategy has been described for the preparation of CF 3 -containing oxindole derivatives using a visible-light-promoted trifluoroethylation reaction of N -arylacrylamides with trifluoroethyl iodide. These reactions could be carried out at room temperature in good to excellent chemical yields with good functional-group tolerance.

Highly efficient approaches to obtain 6-trifluoromethyl-phenanthridine derivatives have been realized through the palladium-catalyzed intramolecular C–H bond functionalization of trifluoroacetimidoyl chlorides. The reaction allows the direct formation of CSp2–CSp2 bonds via C–H bond functionalization and rapid access to phenanthridine ring systems in moderate to high yields with good functional group tolerance.

Two coordination polymers, namely {[Mn(2,4′-bpdc)(bimb)(H2O)0.5]·0.5H2O}n (1) and [Mn(4,4′-bpdc)(bimb)]n·2.5H2O (2) [2,4′-bpdc = biphenyl-2,4′-dicarboxylate, 4,4′-bpdc = biphenyl-4,4′-dicarboxylate, and bimb = 1,4-bis(1-imidazol-yl)-2,5-dimethyl benzene], were hydrothermally synthesized by reactions of manganese(II) salt with the rigid ligand 1,4-bis(1-imidazol-yl)-2,5-dimethyl benzene and isomeric biphenyl dicarboxylate ligands. Complex 1 has an unusual 6-connected three-dimensional (3D) architecture with point symbol (44.611). Complex 2 has also a 3D structure with two-interpenetrated pcu topology with point symbol (412.63). Structural comparisons show that the positions of the carboxylate groups in the ligand backbone play an important role in governing the structural topologies of these complexes.

Two new zinc coordination polymers are synthesized at the present of the different solvent. Complex [Zn(pbc)2]n (1) and complex [Zn(pbc)· (DMF)]n (2) (Hpbc = 3-pyrid-3-ylbenzoic acid, DMF = N,N-dimethyl formamide and NMF = N-methyl formamide) are isomers with one-dimensional frameworks, but the resulting Zn(II) coordination numbers are different. The single-crystal-to-single-crystal transformation appears between complexes 1 and 2.

A mild and efficient method for the synthesis of 6-difluoromethylenephosphonyl-phenanthridines through visible-light-promoted radical difluoromethylenephosphonation of 2-isocyanobiaryls with bromodifluoromethylphosphonate has been developed. The reaction allows the direct formation of Csp2 CF2PO(OEt)2 and C C bonds via a proposed tandem radical cyclization process.

A convenient and efficient method for oxidative coupling of tetrahydroisoquinoline derivatives with trimethyl(trifluoromethyl)silane and terminal alkynes to 1-trifluoromethylated or 1-alkynylated tetrahydroisoquinolines via C H activation was developed using visible light irradiation. The protocol uses Rose Bengal as the catalyst, air as terminal oxidant, and the trifluoromethylation or alkynylation was selectively performed at the α-position of nitrogen under extremely mild conditions.

A convenient and efficient method for the synthesis of 3-halofurans was developed by using a cascade reaction between 1-(1-alkynyl)cyclopropyl ketones and cupric halide. Under mild reaction conditions, both 3-chloro- and 3-bromofuran derivatives were obtained in high yields. The reaction involves consecutive multiple bond formations, includingC–O and C–Br bonds, with high regioselectivity. Mechanistic aspects are described.

School of Chemistry and Environmental Science, Guizhou University for Nationalities, Guiyang 550025, P. R. ChinaReceived November 21, 2011, Accepted December 21, 2011Key Words : Gold, Homocoupling, Terminal alkyne, DiyneDiyne compounds have received considerable attention inview of their applications in the field of material chemistrysuch as linearly π-conjugated acetylenic oligomers, polymersmacrocycles and supramolecular scaffolds.

A highly efficient cyclization reaction of trifluoromethylated propargylamines leading to 2-trifluoromethyl-4-aryl quinolines was developed by using gold(I) as a catalyst under extremely mild conditions.

An efficient synthetic method for the preparation of quinolines through indium(III) chloride-catalyzed tandem addition-cyclization-oxidation reactions of imines with alkynes was developed. The processes can provide a diverse range of quinoline derivatives in good yields from simple imines and alkynes.

A copper-catalyzed tandem intramolecular cyclization-addition reaction of N-(o-alkynylphenyl)imines is disclosed. This strategy offers a simple and promising method for accessing ring-fused indoles. Copyright © 2010 John Wiley & Sons, Ltd.

A convenient and efficient method for fluorination of methylenecyclopropanes is reported. This is exemplified in the stereoselective preparation of N-[(E)-3-fluorobut-3-en-1-yl]-benzenesulfonimides by the reaction of methylenecyclopropanes with N-fluorobenzenesulfonimide in good to excellent yields. Moreover, γ-fluorohomoallylic amides are synthesized using Selectfluor in R3CN at 60 °C.

A highly efficient tandem cyclization reaction of N-(o-alkynylphenyl)imines leading to ring-fused indoles was developed by using gold(III) as a catalyst under extremely mild reaction conditions.

An electrodeposition route for preparation of well-controlled magnesium hydroxide nanostructure using sodium acetate as structure-directing agent was presented. The magnesium hydroxide thin films were characterized by XRD, SEM and TEM. The influence of synthesis parameters on the morphological characteristics and size of magnesium hydroxide thin films deposited from nitrate bath was investigated, such as concentration of sodium acetate additive and applied potential. A possible mechanism responsible for morphologies evolution of thin films was also elucidated. This electrochemical process may be extended to fabricate other nano-/mesostructures with diverse morphologies and unique properties under convenient and mild conditions.

Facile, scale-up, and controllable fabrication of lamellar-like Mg(OH) 2 on a magnesium substrate through natural oxidation of Mg metal in formamide/water mixtures has been demonstrated. The one-step, wet-chemical approach has displayed well-controlled growth of densely packed magnesium hydroxide with large-area homogeneity and uniform morphology. The chemical-liquid-deposition process, an analogue to the widely used chemical-vapor-deposition technique, has been well developed for production of specific morphological Mg(OH) 2 through continuous supply, transport, and thermal decomposition of magnesium complexes in a liquid phase. The formation mechanism of lamellar-like Mg(OH) 2 was also discussed based on experimental phenomena.

Highly textural lamellar mesostructured Mg(OH)2 thin films were obtained through one-step cathodic reduction of magnesium nitrate bath without any surfactant template at room temperature. Its microstructure, stability and morphology were investigated using XRD, TEM, FT-IR, thermal analysis and SEM technique respectively. The results indicate that the porous hydroxide/oxide materials have highly textural lamellar structures with layer spacing around 3.4 nm. The possible formation mechanism has been discussed.

A mild and efficient method for the synthesis of 3-difluoroacetylated coumarins through visible-light-promoted aryldifluoroacetylation of alkynes with ethyl bromodifluoroacetate has been developed. The reaction allows the direct formation of Csp2–CF2COOEt and C–C bonds via a proposed tandem radical cyclization process.

A simple and practical approach to oxindole derivatives via visible-light-photocatalyzed aryldifluoroacetylation of N-arylacrylamides with BrCF2CO2Et has been developed. This method provides convenient access to a variety of difluoroester-substituted oxindoles under mild conditions.

A mild and efficient method for the synthesis of 3-difluoroacetylated coumarins through visible-light-promoted aryldifluoroacetylation of alkynes with ethyl bromodifluoroacetate has been developed. The reaction allows the direct formation of Csp(2)-CF2COOEt and C-C bonds via a proposed tandem radical cyclization process.

A practical strategy has been described for the preparation of 6-trifluoroethyl-phenanthridine derivatives using a visible-light-promoted trifluoroethylation reaction of 2-isocyanobiaryl with trifluoroethyl iodide. These reactions could be carried out at room temperature in good to excellent chemical yields with good functional group tolerance.

A convenient and efficient method for the synthesis of 3-halofurans was developed by using a cascade reaction between 1-(1-alkynyl)cyclopropyl ketones and cupric halide. Under mild reaction conditions, both 3-chloro- and 3-bromofuran derivatives were obtained in high yields. The reaction involves consecutive multiple bond formations, includingC–O and C–Br bonds, with high regioselectivity. Mechanistic aspects are described.

A convenient method for oxidative coupling of tetrahydroisoquinoline derivatives (I) with trimethyl(trifluoromethyl)silane (II) and terminal alkynes (IV) via selective C—H activation is described.

The products (II) and (IV) are formed in good to very good yields tolerating various electron-donating and electron-deficient substituents on the aromatic groups.

A copper-catalyzed tandem intramolecular cyclization-addition reaction of N-(o-alkynylphenyl)imines is disclosed. This strategy offers a simple and promising method for accessing ring-fused indoles. Copyright © 2010 John Wiley & Sons, Ltd.

A convenient and efficient method for fluorination of methylenecyclopropanes is reported. This is exemplified in the stereoselective preparation of N-[(E)-3-fluorobut-3-en-1-yl]-benzenesulfonimides by the reaction of methylenecyclopropanes with N-fluorobenzenesulfonimide in good to excellent yields. Moreover, γ-fluorohomoallylic amides are synthesized using Selectfluor in R3CN at 60 °C.