Synthesis and Crystal Structure of 1,2Bis（2-benzimidazolyl） benzene

The title compound C6H4(C7H5N2)2 was prepared by the condensation of o-phenyl- enediamine with o-phthalic acid and characterized by elemental analysis, IR, UV and H NMR 1 spectra, and its structure was determined by single-crystal X-ray diffraction. The crystal belongs to orthorhombic system, space group Pbcn with a = 17.928(8), b = 8.828(4), c = 9.752(4)?, Z = 4, V = 1543.4(12) ?3, Dc = 1.336 g/cm3, Mr = 310.35, λ(MoKα) = 0.71073 ?, μ = 0.082 mm-1, F(000) = 648, R = 0.0405 and wR = 0.1092. A total of 1693 unique reflections were collected, of which 1319 with I > 2σ(I) were observed. It is shown that the compound molecule belongs to C2 point group. A one-dimensional chain structure was formed by the intermolecular hydrogen bonds (N(2)–H… N(1)).

Study on the Nanosized Amorphous Ru-Fe-B/ZrO_2 Alloy Catalyst for Benzene Selective Hydrogenation to Cyclohexene

A novel nanosized amorphous Ru-Fe-B/ZrO2 alloy catalyst for benzene selective hydrogenation to cyclohexene was investigated. The superior properties of this catalyst were attributed to the combination of the nanosize and the amorphous character as well as to its textural character. In addition, the concentration of zinc ions, the content of ZrO2 in the slurry, and the pretreatment of the catalyst were found to be effective in improving the activity and the selectivity of the catalyst.

Inhibition of DNA-dependent Protein Kinase Catalytic Subunit by Small Molecule Inhibitor NU7026 Sensitizes Human Leukemic K562 Cells to Benzene Metabolite-induced Apoptosis

Benzene is an established leukotoxin and leukemogen in humans. We have previously re- ported that exposure of workers to benzene and to benzene metabolite hydroquinone in cultured cells induced DNA-dependent protein kinase catalytic subunit （DNA-PKcs） to mediate the cellular response to DNA double strand break （DSB） caused by DNA-damaging metabolites. In this study, we used a new, small molecule, a selective inhibitor of DNA-PKcs, 2-（morpholin-4-yl）-benzo[h]chomen-4-one （NU7026）, as a probe to analyze the molecular events and pathways in hydroquinone-induced DNA DSB repair and apoptosis. Inhibition of DNA-PKcs by NU7026 markedly potentiated the apoptotic and growth inhibitory effects of hydroquinone in proerythroid leukemic K562 cells in a dose-dependent manner. Treatment with NU7026 did not alter the production of reactive oxygen species and oxidative stress by hydroquinone but repressed the protein level of DNA-PKcs and blocked the induction of the kinase mRNA and protein expression by hydroquinone. Moreover, hydroquinone increased the phos- phorylation of Akt to activate Akt, whereas co-treatment with NU7026 prevented the activation of Akt by hydroquinone. Lastly, hydroquinone and NU7026 exhibited synergistic effects on promoting apop- tosis by increasing the protein levels of pro-apoptotic proteins Bax and caspase-3 but decreasing the protein expression of anti-apoptotic protein Bcl-2. Taken together, the findings reveal a central role of DNA-PKcs in hydroquinone-induced hematotoxicity in which it coordinates DNA DSB repair, cell cycle progression, and apoptosis to regulate the response to hydroquinone-induced DNA damage.

Robust photocatalytic benzene degradation using mesoporous disk-like N-TiO2 derived from MIL-125(Ti)

N-doped anatase-rutile titanium dioxide(N-TiO2)is a classical semiconductor widely used in environmental remediation.Its photocatalytic performance is typically affected by its morphology,porous structure,and phase composition.Herein,disk-like mesoporous N-TiO2 was prepared by calcining MIL-125(Ti)and melamine matrix at different temperatures in air.The photocatalytic efficiency of the prepared mesoporous N-TiO2 for the photo-oxidation of gaseous benzene under visible-light irradiation was studied.With respect to light absorption and mass transfer,as-prepared N-TiO2 annealed at 500℃(MM-500)showed the best photocatalytic activity with corresponding photodegradation and mineralization efficiencies of 99.1%and 72.0%,respectively.In addition.MM-500 exhibited excellent reusability and stability in cyclic experiments,in which 84.8%of gaseous benzene could still be photodegraded after 10 experimental cycles.Furthermore,electron spin resonance analysis indicated that·OH and·O2-radicals were the dominating reactive oxygen species during the photo-oxidation process.Their excellent performance suggests that the as-prepared N-TiO2 photocatalysts can be used to eliminate volatile organic compounds.

Catalytic Synthesis of Isopropyl Benzene over SO_4 ^(2-)/ZrO_ 2-MCM-41

Super acid catalyst SO4^2-/ZrO2 was introduced into pure silicone MCM-41 via the impregnation method and the catalyst samples obtained at different temperatures were characterized by means of XRD, IR, and Py-IR techniques. The selectively catalytic gas-phase flow reactions of benzene with propene over the catalyst samples were carried out in a made-to-measure high-pressure flow reactor equipped with a thermostat and a condenser. Effect of the preparative condition on the catalytic synthesis of isopropyl benzene over the catalyst samples was tested. The results show that SO4^2-/ZrO2-MCM-41 （ SZM-41 ） can be used as a catalyst for the title reaction, in which there are a higher conversion （97%） for the propene and a higher selectivity（93% ） for the isopropyl benzene.

Detection of CYP2E1,a Genetic Biomarker of Susceptibility to Benzene Metabolism Toxicity in Immortal Human Lymphocytes Derived from the Han Chinese Population

Objective Cytochrome P450 2E1 （CYP2E1） is an important metabolizing enzyme involved in oxidative stress responses to benzene, a chemical associated with bone marrow toxicity and leukemia, We aimed to identify the CYP2E1 genetic biomarkers of susceptibility to benzene toxicity in support of environmental and occupational exposure prevention, and to test whether a model using immortal human lymphocytes might be an efficient tool for detecting genetic biomarkers. Methods Immortalized human lymphocyte cell lines with independent genotypes on four CYP2E1 SNP sites were induced with 0.01% phenol, a metabolite of benzene. CYP2E1 gene function was evaluated by mRNA expression and enzyme activity. DNA damage was measured by Single-Cell Gel Electrophoresis （SCGE）. Results Among the four SNPs, cells with rs2070673TT and rs2030920CC showed higher levels of ~YP2E1 transcription and enzymatic activity than the other genotypes in the same SNP site. Cells with higher gene expression genotypes also showed higher comet rates compared with lower gene expression genotypes. Conclusion These results suggest that CYP2E1 rs2070673 and rs2030920 might be the genetic biomarkers of susceptibility to benzene toxicity and that the immortalized human lymphocytes model might be an efficient tool for the detection of genetic biomarkers of susceptibility to chemicals.

Efficient conversion of benzene and syngas to toluene and xylene over ZnO-ZrO_(2)&H-ZSM-5 bifunctional catalysts

A series of ZnO-ZrO_(2) solid solutions with different Zn contents were synthesized by the urea coprecipitation method,which were coupled with H-ZSM-5 zeolite to form bifunctional catalysts.As a new benzene alkylation reagent,syngas was used instead of methanol to realize the efficient conversion of syngas and benzene into toluene and xylene.A suitable ratio of ZnO-ZrO_(2) led to the significant improvement in the catalytic performance,and a suitable amount of acid helped to increase the selectivity of toluene/xylene and reduce the selectivity of the by-products ethylbenzene and C^(9+) aromatics.The highest benzene conversion of 89.2%and toluene/xylene selectivity of 88.7%were achieved over 10%ZnO-ZrO_(2)&H-ZSM-5(Si/Al=23)at a pressure of 3 MPa and a temperature of 450℃.In addition,the effect of the zeolite framework structure on product distribution was examined.Similar to the molecular dynamics of aromatic hydrocarbons,H-ZSM-5 zeolites comprise 10-membered-ring pores,which are beneficial to the activation of benzene;hence,the conversion of benzene is higher.H-ZSM-35 and HMOR zeolites exhibited small eight-membered-ring channels,which were not conducive to the passage of benzene;hence,the by-product ethylbenzene exhibits a higher selectivity.The distance between the active centers of the bifunctional catalysts was the main factor affecting the catalytic performance,and the powder mixing method was more conducive to the conversion of syngas and benzene.

Study of a Ru-La/ZrO_2 Catalyst Prepared by Precipitation Method for Selective Hydrogenation of Benzene to Cyclohexene

A Ru-La/ZrO2 catalyst was prepared by the precipitation method, in which Ru was an active component, La was a promoter and ZrO2 was a dispersant. Comparing with the catalyst prepared by the chemical reduction method, the Ru-La/ZrO2 exhibited higher activity and better selectivity. At 140 ℃ and hydrogen pressure of 5 MPa, the C6H10 selectivity reached 70% at a C6H6 conversion of 35% for a reaction time was 5 min and the total La/Ru loading was 10%. Textural parameters of the catalyst were obtained by physical adsorption, BET surface area and specific pore volume measurements. The catalyst sample gave a BET area of 41 m2/g and a specific pore volume of 1.1 cm^3/g, and the most probable pore distribution was located at 5 to 10 nm. H2-TPR measurements showed that ruthenium oxide could be reduced to its metallic state at about 403 K. XRD determinations indicated that ruthenium and lanthanum were highly dispersed on the zirconia. A significant advantage of the Ru-La/ZrO2 catalyst is that it can be used directly in its unreduced state for the selective hydrogenation of benzene.

Solid-Liquid Equilibria of Musk Ketone, Musk Xylene and 1,3-Dimethyl-2,4-Dinitro-5-Tert-Butyl Benzene

The solid-liquid equilibria of musk ketone + musk xylene, musk xylene +l,3-dimethyl-2,4-dinitro-5-tert-butyl benzene are measured by differential scanning calorimeter (DSC), these systems are proved to be simple eutectics. Moreover the melting points and the fusion enthalpies of musk ketone, musk xylene and 1,3-dimethyl-2,4-dinitro-5-tert-butyl benzene are also measured by the DSC. These solid-liquid equilibrium data and the heats of fusion are reported for the first time. Then UNIFAC model is used to correlate the sofid-liquid equilibrium data. It is shown that the solid-liquid equilibria of musk systems can be predicted by the UNIFAC model.

Synthesis,Crystal Structure,and Magnetic Property of One 3D Nickel Coordination Polymer Based on 2-Hydroxy-5-(3',5'-terephthalic acid)Pyridine and 1,4-Bis(1-imdazoly)benzene

One novel nickel coordination polymer, {[Ni（OTP）（bib）1.5（H2O）]·2H2O}n（1, H2 OTP = 2-hydroxy-5-（3＇,5＇-terephthalic acid） pyridine, bib = 1,4-bis（1-imdazoly）benzene）, has been synthesized and characterized by elemental analysis（EA）, IR, powder X-ray diffraction（PXRD）, and thermogravimetric（TG） analyses. The crystal of 1 crystallizes in monoclinic, space group P21/n with a = 12.2860（5）, b = 13.8246（6）, c = 19.0140（8） A, β = 104.3870（1）°, V = 3128.2（2） A3, Z = 4, C32H28N7 Ni O8, Mr = 697.32, Dc = 1.481 g/cm^3, F（000） = 1444 and μ（Mo Kα） = 0.684 mm-1. The final R = 0.0704 and w R = 0.1764 for 5485 observed reflections with I 2σ（I） and R = 0.1087 and wR = 0.2010 for all data. Topology analysis reveals that complex 1 is a 3D 2-fold interpenetrated {4^4·6^6}-nov net based on the 1D [Ni（OTP）]n chain and the 2D [Ni2（bib）3]n sql sheet. And the variable-temperature magnetic susceptibility measurements exhibit weak antiferromagnetic coupling interaction.

Synthesis and Crystal Structure of Binuclear Silver(I) Complex with 2-nitro-(2-pyridylsulfanylmethyl)benzene

The reaction of 2-nitro-（2-pyridylsulfanylmethyl）benzene L with silver nitrate produces a centrosymmetric binuclear complex bis（2-nitro-（2-pyridylsulfanylmethyl）benzene-N,S）- bis（nitrato-O,O）-disilver（Ⅰ）, [AgLNO3]2 1. The crystal is of triclinic, space group PI, with a = 7.383 （3）, b = 8.340（3）, c = 12..003（4） A, a = 95.069（6）, β = 93.498（5）, γ = 102.734（6）°, C24H20Ag2N6- O10S2, Mr= 832.32, V = 715.6（4） ,A^3, Z = 1, Dc = 1.931 g/cm^3, F（000） = 412,μ = 1.581 mm^-1, R= 0.0351 and wR = 0.0749 Each silver atom is tetrahedrally coordinated by two O atoms from bidentate nitrate, one S atom from a ligand and one N atom from another ligand. Furthermore, Ag- Ag interactions have been observed in the complex.

Colloidal Dispersion of Nano-Ru/SiO_2 in PEG and its Application for Hydrogenation of Benzene

Colloidal dispersion of nano-Ru/SiO2 in PEG （polyethylene glycol, M.W.=400） was used for benzene hydrogenation. The system has the features of easy catalyst＇s recycling and high catalyst stability.

Synthesis and Crystal Structure of 1,4-Dimethyl-2,5-di{[2’-(3-pyridylmethylamino-formyl)phenoxyl]methyl}benzene Perchlorate

The title compound, 1,4-dimethyl-2,5-di { [2′-（3-pyridylmethylaminoformyl）phenoxyl]- methyl}benzene perchlorate （C36H36Cl2N4O12, Mr = 787.59）, has been synthesized and structurally determined by single-crystal X-ray diffraction. The crystal crystallizes in the orthorhombic system, space group Pbca with a = 14.366（4）, b = 15.159（4）, c = 16.443（5）A, V = 3580.9（17）/A3 Z = 4, De = 1.461 g/cm^3, /t = 0.253 mm^-1, F（000） = 1640, R = 0.0618 and wR = 0.1525 for 1615 observed reflections （I 〉 2σ（I））. In the structure of the title compound, a two-dimensional supramolecular layer is formed via intermolecular hydrogen bonding interactions.

Steady-state kinetics and osillation phenomena for complete oxidation of benzene over Pt/Al_2O_3 catalyst

The steady-state kinetics for complete oxidation of benzene over has been investigated by the external recycling reactor. The kinetics equation was described by the L-H model of adsorption of benzene and oxygen with the inhibition of carbon dioxide. The parameters of the kinetics model were estimated by the method of orthogonal design. The heats of adsorption of benzene, oxygen and carbon dioxide were determined by the method of gas-adsorption chromatography. The details of oscillations of complete oxidation of benzene were investigated.

Synthesis and Crystal Structure of cis-[1,2-Bis(phenyl-thiomethyl)benzene]dichloroplatinum(Ⅱ)·0.5acetonitrile

The title complex was prepared from the reaction of 1,2-bis(phenylthiomethyl)- benzene L with K2PtCl4 at room temperature and its structure has been determined by single-crystal X-ray diffraction. There exist two independent cis-[1,2-bis(phenylthiomethyl)benzene]dichloro- platinum(Ⅱ) [PtCl2L] molecules without significant structural difference and a molecule of acetonitrile in one crystallographic asymmetric unit. Crystallographic data: triclinic, space group Pī, a = 11.010(3), b = 12.080(3), c = 16.095(4) ? = 94.728(5), = 90.129(5), = 99.274(5)? C20H18Cl2NPtS20.5CH3CN, Mr = 608.98, V = 2105(1) ?, Z = 4, Dc = 1.921 g/cm3, (Mo-K) = 7.122 mm1, F(000) = 1172, R = 0.0503 and wR = 0.0848 for 3929 observed reflections with I > 2s(I). The title complex is a neutral molecule in which the central Pt(Ⅱ) ion is four-coordinated with two S-donors of the ligand and two Cl anions, forming a distorted square planar geometry. In the crystal, there exist two kinds of molecular packing patterns. One [PtCl2L] molecule is connected to the other one through the weak interactions of Pt…Pt, Pt…S and Pt…Cl, forming a supramolecular quasi-dimer. The other one complex molecule is connected with the CH3CN molecule by weak Cl…N interaction.

Influence of ultrasonic on the coking amount of catalyst （Ni/γ-Al2O3） for the dry reforming of benzene

The Influence of ultrasonic treatment on the coking amount of a nickel-based catalyst （Ni/γ-Al2O3） for the reaction of reforming with carbon dioxide of Benzene was investigated. The results show that ultrasonic treatment modify the pore size distribution of the catalysts significantly and also reduce the amount of coke formed on the catalyst. The reduction in the coking amount is not sensitive to the power output of the ultrasonic treatment device in the power range tested （120 W and 500 W）.

Comparative Studies of 1,4-Bis[2-(4-Pyridyl)ethenyl]-benzene Using Density Functional Theory

The optimized molecular structure and harmonic vibrational frequencies of a 1,4-bis [ 2-（4-pyridyl）ethenyl]- benzene（BPENB） molecule were calculated via five popular density functional theory（DFI＇） methods. On the basis of the comparison between calculated and experimental results, it is concluded that the B3PW91 and B3LYP methods are superior to the others in optimizing structures, and the BPW91 method reproduces the observed fundamental fre-quencies most satisfactorily.

纳米TiO_(2)微球的制备及光催化降解气相苯特性

以四氯化钛和尿素为原料,通过溶剂热法制备了纳米TiO_(2)微球。利用XRD、FE-SEM、TEM、UV-Vis、BET测试手段对样品的组成、结构、形貌、光学性能、比表面特性进行分析,以气相苯为目标降解物,研究不同溶剂热时间所制备的微球对光催化活性的影响。结果表明,随溶剂热时间的延长,TiO_(2)微球结构经历了实心-核壳-空心的演变过程,但均由20 nm以下的颗粒组成。此类微球的光吸收带边出现明显“蓝移”现象,且光吸收性能较P25 TiO_(2)要高,比表面积是其3~5倍。其中溶剂热时间为6 h所制备的核壳结构微球光催化活性最佳,降解气相苯的矿化率高达93%,高于P25 TiO_(2)近3倍,分析表明,该优异性能得益于核壳结构对光的充分反射吸收和高比表面积导致的吸附协同光催化特性。

Coking and Deactivation of Catalyst Inhibited by Silanization Modification in Oxidation of Benzene to Phenol with Nitrous Oxide

The main cause to the deactivation of ZSM-5 catalyst, used for oxidation of benzene to phenol (BTOP) by nitrous oxide, is that the carbon deposition on the catalyst surface blocks the mouth of pores of the catalyst.In the experiments, ZSM-5 catalyst was modified by chemical surface deposition of silicon, and then the effect of modification condition on the catalyst activation was studied. The catalyst samples were characterized by XRF,EPS, XRD, TEM, N2 adsorption at low temperature, pyridine adsorption-infrared technique and etc. All the above results show that the uniform SiO2 membrane can be formed on ZSM-5 crystal surface. The SiO2 membrane covers the acid centers on ZSM-5 surface to inhibit surface coking, to avoid or decrease the possibility of ZSM-5 pore blockage so that the catalyst activity and stability can be improved efficiently. The optimum siliconiting conditions determined by the experiments are as follows: 4% load of silanizing agent, volume (ml)/mass (g) ratio of hexane/ZSM-5=15/1, and 16 h of modification time. Compared with the samples without siliconiting treatment,the samples treated under the above optimum condition can increase the productivity of phenol by 14% for 3 h reaction time and by 41% for 6 h reaction time respectively.

Nondoped-type White Organic Light-Emitting Diode Using Star-Shaped Hexafluorenylbenzene as an Energy Transfer Layer

White organic light-emitting diodes （WOLEDs） with a structure of indium-tin-oxide （ITO）/N,N＇-bis- （1-naphthyl）-N,N＇-diphenyl- （1, 1＇-biphenyl）-4,4＇-diamine （NPB）/1,2,3,4,5,6-hexakis（9,9-diethyl-9H-fluoren-2- yl）benzene （HKEthFLYPh）/5,6,11,12-tetraphenylnaphtacene （rubrene）/tris（8-hydroxyquinoline） aluminum （Alq3）/Mg：Ag were fabricated by vacuum deposition method, in which a novel star-shaped hexafluorenyl- benzene HKEthFLYPh was used as an energy transfer layer, and an ultrathin layer of rubrene was inserted between HKEthFLYPh and Alq3 layers as a yellow light-emitting layer instead of using a time-consuming doping process. A fairly pure WOLED with Commissions Internationale De L＇Eclairage （CIE） coordinates of （0.32, 0.33） was obtained when the thickness of rubrene was 0.3 nm, and the spectrum was insensitive to the applied voltage. The device yielded a maximum luminance of 4816 cd/m2 at 18 V.