Allyl phthalazinone synthesis,polymerization and polymer properties

A phthalazinone monomer with an allyl group, i.e. 4-（3-allyl-4-hydroxyphenyl）phthalazin-1（2H）-one, was synthesized and then copolymerized with 4-（4-hydroxylphenyl）（2H）-phthalazin-1-one and 2,6- diflurobenzonitrile by means of aromatic nucleophilic polycondensation to provide a series of crosslinkable poly（aryl ether nitrile）s. The virgin copolymers exhibited good solubility in polar organic solvents with relative high molecular weights （Mw： 45,130-58,403, inherent viscosities： 0.58-0.75 dL/ g）. After cross-linking, the thermal stability and solvent resistance of the polymer increased.     

Nickel-catalyzed cross-coupling reaction of alkynyl bromides with Grignard reagents

We describe a convenient method for the synthesis of 1,2-disubstituted acetylenes via a cross-coupling reaction of （bromoethynyl）benzene with Grignard reagents. The reaction of （bromoethynyl）benzene （1 mmol） with Grignard reagent （1.3 mmol） mediated by NiCl2 （4 mol%） and （p-CH3Ph）3P （8 mol%） in THF could produce 1,2-disubstituted acetylenes in good yields at room temperature.     

Chemoselective hydrogenolysis of tetrahydrofurfuryl alcohol to 1,5-pentanediol over Ir-MoOx/Si02 catalyst

In this work, MoOx promoted Ir/SiO2 catalysts were prepared and used for the selective hydrogenolysis of tetrahydrofurfuryl alcohol （THFA） to 1,5-pentanediol in a continuous flow reactor. The effects of different noble metals （Ir, Pt, Pd, Ru, Rh）, supports and Ir contents were screened. Among the investigated catalysts, 4 wt%Ir-MoOx/SiO2 with a Mo/Ir atomic ratio of 0.13 exhibited the best catalytic performance. The synergy between Ix particles and the partially reduced isolated MoOx species attached on them is essential for the excellent catalytic performance of Ix-MoOx/SiO2. The catalyst exhibited a better hydrogenolysis efficiency of THFA with the selectivity of 1,5-pentanediol of 65%-74% at a conversion of THFA of 70%-75% when the initial THFA concentration is ranging from 20 wt% and 40 wt%. And higher system pressure was also in favor of the conversion of THFA. During a stability test, the conversion of THFA and 1,5-pentanediol yield over Ix-MoOz/SiO2 decreased with reaction time, which can be explained by the leaching of Mo species during the reaction.     

Effect of the graphitic degree of carbon supports on the catalytic performance of ammonia synthesis over Ba-Ru-K/HSGC catalyst

A series of high surface area graphitic carbon materials （HSGCs） were prepared by ball-milling method. Effect of the graphitic degree of HSGCs on the catalytic performance of Ba-Ru-K/HSGC-x （x is the ball-milling time in hour） catalysts was studied using ammonia synthesis as a probe reaction. The graphitic degree and pore structure of HSGC-x supports could be successfully tuned via the variation of ball-milling time. Ru nanoparticles of different Ba-Ru-K/HSGC-x catalysts are homogeneously distributed on the supports with the particle sizes ranging from 1.6 to 2.0 nm. The graphitic degree of the support is closely related to its facile electron transfer capability and so plays an important role in improving the intrinsic catalytic performance of Ba-Ru-K/HSGC-x catalyst.     

A New Terbium（III） Coordination Compound with 2-Thiophenecarboxylic Ligand： Synthesis and Crystal Structure①

A new coordination compound with formula [Tb（2-TC）3（DMF）]n （1, 2-TC = 2-thio- phenecarboxylic ligand and DMF = dimethylformamide） was synthesized by solvothermal method. The structure of compound 1 was determined by single-crystal X-ray diffraction analyses, and characterized by elemental analyses, IR and powder X-ray diffraction. Structure analysis reveals compound 1, exhibiting a one-dimensional chain structure, crystallizes in triclinic space group P21/c, with a = 9.2751（19）, b = 16.490（3）, c = 15.865（5） A, β = 118.98（2）°, V= 2122.7（9）A3, D,. = 1.916 g/cm3, Mr= 612.45 （C18H15NO7S3Tb）, F（000） = 1196,μ（MoKa） = 3.67 mm-1, Z = 4, R = 0.0616 and wR = 0.0962 for 3865 observed reflections （I 〉 2o（I））, and R = 0.1092 for all data. Meanwhile, the photoluminescent properties of compound 1 were also investigated in the solid state at room temperature.     

Syntheses,Crystal Structures,and Properties of a New Lead(Ⅱ) Complex Involving Holo-and Hemidirected Coordination Spheres with 3,5,6-Tris(2-pyridyl)-1,2,4-triazine Ligand

[Pb(TPT)(μ-I)2PbI2(μ-I)2Pb(TPT)] 1(TPT is the abbreviation of 3,5,6-tris(2-pyridyl)-1,2,4-triazine ligand) has been synthesized and characterized by elemental analysis, IR, 1HNMR spectroscopy and studied by thermal and electrochemical properties as well as X-ray crystallography. The single-crystal X-ray data show two different kinds of Pb2+ ions in 1 with coordination numbers of six, Pb1 = PbI6, and five, Pb2 = PbN3I2, with holodirected and hemidirected coordination spheres, respectively. The supramolecular features in 1 are negotiated through the weak but directional Pb···I, C–H···N and C–H···I interactions and aromatic π-π stacking interactions.     

A New Cadmium（II） Coordination Polymer Constructed by 2-（2-Chloro-6-fluorophenyl）-lH-imidazo[4,5-f] [1, 10]phenanthroline and 1,2,3-Benzenecarboxylate： Synthesis,Structure and Luminescence

A new Cd（II） coordination polymer, namely, [Cd3（1,2,3-BTC）2（L）2]·2.25H2O （1, L = 2-（2-chloro-6-fluorophenyl）-1H-imidazo[4,5-A][1,10]phenanthroline and 1,2,3-BTC = 1,2,3-ben- zenetricarboxylate）, has been synthesized under hydrothermal conditions. The compound was characterized by single-crystal X-ray diffraction. It crystallizes in triclinic, space group Pī with α = 11.650（2）, b = 12.240（2）, c = 19.760（4） A, α = 72.01（3）, β = 77.11（3）, γ = 83.48（3）°, V = 2609.4（9） A3, Z = 2, C56H31Cd3Cl2F2N8O14.25, Mr = 1489.99, Dc = 1.896 g/cm3, F（000） = 1466, μ（MoKa） = 1.401 mm^-1, R = 0.0401 and wR = 0.1104. Compound 1 shows a 1D chain structure, and the neigh- boring 1D chains of 1 are joined together by π···π interactions to result in a 2D supramolecular layer. In addition, the luminescent property of 1 has been studied in the solid state at room temperature.     

Effect of Molecular Weight on the Properties of Poly（butylene succinate）

Poly（butylene succinate） （PBS） with different molecular weight was synthesized from 1, 4-butanediol and succinic acid by direct melt condensation. The synthesized PBS was identified by IH-NMR and FTIR spectrometry. The molecular weight was calculated from the intrinsic viscosity, and its value was between 20000 and 70000. The crystallization behavior and crystal morphology as function of molecular weight were investigated by DSC and PLM, respectively. The mechanical properties and hydrolytic degradation behaviors related with change of molecular weight were also studied in this work. The results demonstrated that the properties of PBS were determined by both molecular weight and crystallization properties （crystallinity as well as crystal morphology）. Our work is important for the design and preparation of PBS with proper molecular weight for its practical application.     

Iron-mediated AGET ATRP of styrene and methyl methacrylate using ascorbic acid sodium salt as reducing agent

Atom transfer radical polymerization of styrene(St) and methyl methacrylate(MMA) in bulk and in different solvents using activators generated by electron transfer(AGET ATRP) were investigated in the presence of a limited amount of air using FeCl3·6H2O as the catalyst, ascorbic acid sodium salt(AsAc-Na) as the reducing agent, and a cheap and commercially available tetrabutylammonium bromide(TBABr) as the ligand. It was found that polymerization in THF resulted in shorter induction period than that in bulk and in toluene for AGET ATRP of St, while referring to AGET ATRP of MMA, polymerization in THF showed three advantages compared with that in bulk and toluene: 1) shortening the induction period, 2) enhancing the polymerization rate and 3) having better controllability. The living features of the obtained polymers were verified by chain end analysis and chain-extension experiments.     

Investigation of Hydrolysis in Poly（ethylene terephthalate） by FTIR-ATR

The hydrothermal aging of poly(ethylene terephthalate)(PET) was investigated at 70 95 °C. A new method to investigate the hydrolysis degree of PET by Fourier transform infrared spectroscopy(FTIR) was proposed. The spectra during the hydrothermal aging were measured using attenuated total reflection accessory(ATR). Peak resolving of carbonyl regions was performed, and the ratio of two groups of bands representing carboxylic acids and esters respectively were calculated to show the hydrolysis degree of ester groups in PET. The acid/ester ratio shows exactly the same trend as the average chain scission number per unit mass at various temperatures and thus can be used as a parameter to characterize the hydrolysis and random chain scission of PET. This method related to the hydrolysis mechanism directly, is simple, fast and convenient compared to the traditional methods such as viscometry, end-group titration and size exclusion chromatography(SEC). It may also be useful in hydrolysis characterization of other polyesters.