Studies of Solvent Effects on Structure and Low Frequency Vibrational Spectra of 2,4-Dinitrotoluene

Solvent effects on 2,4-dinitrotoluene（2,4-DNT） molecule in different solvents（toluene, ethanol, and water） were studied via DFT PCM method at B3LYP/6-311＋G（d,p） level. The influences of these solvents on the molecular structure, vibrational spectra, charge distribution, and dipole moment were studied as well. The results show that PCM computations are successful in describing the vibrational spectra of 2,4-DNT molecules in these solutions and the solvent effects on the low frequency vibrational spectra are weak.

Advanced Oxidation Process for DNAN Using UV/H2O2

2,4-Dinitroanisole(DNAN)is an important component of insensitive munitions that is anticipated to replace 2,4,6-trinitrotoluene(TNT)in munitions formulations.Photocatalyzed hydrogen peroxide(H2O2)oxidation experiments and chemical analyses were conducted to study the effect of initial pH and H2O2 dosage on the kinetics of DNAN decomposition and the reaction pathways.The results show that DNAN degradation followed zero-order kinetics when a 250 ppm DNAN solution was treated with ultraviolet(UV)light and 1500–4500 ppm H2O2 in an initial pH range of 4–7.However,when the H2O2 concentration was 750 ppm,DNAN degradation followed pseudo-first-order kinetics.The results indicate that DNAN can easily be oxidized by UV/H2O2 treatment.When the H2O2 dosage was 1500 ppm and the initial pH was 7,DNAN was reduced from 250 ppm to less than 1 ppm in 3 h.However,the total organic carbon(TOC)and total carbon(TC)concentrations were reduced slowly from 100 to less than 70 ppm carbon(C)in 3 h,and decreased to about 5 ppm after 9 h of treatment,suggesting the formation of other organic compounds.Those reaction intermediates were oxidized to carbon dioxide(CO2)at a slower rate than the oxidation of DNAN.CO2 was emitted from the solution because the solution pH decreased rapidly to about 3 during the UV/H2O2 oxidation.Most of the nitrogen in DNAN was converted to nitrate by UV/H2O2 oxidation after 9 h of treatment.The research results indicate that UV/H2O2 oxidation is a promising technique for the treatment of DNAN in wastewater.

Degradation of 2,4-dichlorophenoxyacetic acid in water by ozonehydrogen peroxide process

This study reports an investigation into the degradation of 2,4-dichlorophenoxyacetic acid in bubble contactor column by O2/H2O2 process, which is widely used as a principal advanced oxidation process. The degradation of 2,4-dichlorophenoxyacetic acid was studied under different H202/O3 molar ratio and pH value. Meanwhile, TOC removal was investigated both in distilled water and tap water. The influences of ozone transfer and consumed hydrogen peroxide were also discussed. The degradation products and oxidation intermediates were identified by GC-MS and LC-MS. A possible reaction mechanism was thus proposed.

双阳极光电催化氧化降解2,4-二氯苯酚的研究

为提高高级氧化技术对内分泌干扰物的降解和矿化性能,首次研究了(TiO2/Ti-Fe)-石墨毡双阳极光电协同催化氧化体系,并考察了其对2,4-二氯苯酚的光催化氧化降解性能.研究了电流在TiO2/Ti-Fe两阳极上的分配,外加电压,pH等主要因素对2,4-二氯酚降解效率的影响及反应过程中H2O2的生成及积累情况.实验结果表明,本体系不仅具有较高的H2O2生成效率和较强的光催化氧化降解性能,而且该体系可以在较宽的pH范围内工作.在较低的电流密度下反应60 min,2,4-二氯酚的降解率可达95%以上,而矿化率高达80%.

Synthesis, Crystal Structure and Antitumor Activities of 1,2,3,4-Tetrahydroquinoline-2,4-diyl(bisdiphenylphosphine oxide) Derivatives

A novel and efficient Ir-catalyzed 1,4-and 1,2-addition of diphenylphosphine oxide to quinolines was developed to obtain various 1,2,3,4-tetrahydroquinoline-2,4-diyl(bisdiphenylphosphine oxide) derivatives. The structures of these derivatives were characterized by H-RMS and NMR analysis. X-ray crystallography showed that 3 a is in a monoclinic system, space group of P21/c with a = 13.0464(16), b = 12.6244(16), c = 20.210(3)A,β= 105.215(2)o, V =3211.9(7)A^3, Z = 4, F(000)= 1352,μ= 0.42 mm^–1, S = 1.07, the final R = 0.059 and wR = 0.195.The in vitro antitumor activities of target compounds were evaluated by MTT assay against human cancer K562, HL-60, HeLa and BGC-823. The target compounds demonstrated weak or moderate antitumor activity against these cell lines.

水对Amoco法制备2,4-二溴-5-氯苯甲酸反应速率的影响研究

本文以Amoco法将2,4-二溴-5-氯甲苯氧化为2,4-二溴-5-氯苯甲酸为例,考查了反应体系内含水量对反应速率的影响。发现体系内含水量接近11%时,反应速率显著下降甚至终止,但加入乙酸酐可以重新继续反应直至原料完全转化,证明水对Amoco氧化存在抑制作用但其过程可逆。

2,4-二氯苯甲酸的制备

以芳香性卤代烃和戊酸的混合物做溶剂 ,乙酸钴、乙酸锰、溴化物做催化剂 ,由氧气氧化 2 ,4-二氯甲苯制备 2 ,4-二氯苯甲酸 ,反应温度 1 3 0～ 1 40℃ ,压力 0 .8～ 1 .0 MPa,产率 90 .8% ,纯度 99.3 %。

非溶剂法合成2,4-二氯苯甲酸研究

在新型 Co- Mn盐复合催化剂存在下 ,不用溶剂 ,用空气氧化 2 ,4 -二氯甲苯合成了 2 ,4 -二氯苯甲酸 ,并对反应条件和机理进行了研究 .2 ,4 -二氯苯甲酸收率达 92 .5 % ,可以和醋酸溶剂法媲美 .该合成方法环境保护好 ,具有重要的工业应用价值 ,特别适合于替代现有生产工艺 .

臭氧/Mn^(2+)催化降解水溶液中的2,4-二氯苯氧乙酸

以Mn2+为催化剂与臭氧联合降解除草剂2,4-二氯苯氧乙酸(2,4-D)。考察了反应温度、pH、2,4-D初始浓度和臭氧气体流量等因素对2,4-D降解效果的影响。pH对2,4-D降解效果影响很大,当pH=2.0、反应5min时,2,4-D的去除率达99.8%;当pH=10.1、反应20min时,2,4-D的去除率仅为50.0%。反应温度升高、臭氧气体流量增加、2,4-D初始浓度降低均有助于2,4-D降解速率的提高。单独臭氧氧化2,4-D的表观反应速率常数为0.170min-1;催化臭氧氧化2,4-D的表观反应速率常数为0.295min-1,是单独臭氧氧化的1.74倍。2,4-D的Mn2+催化臭氧反应遵循拟一级反应动力学方程。

2，4-二氯-5-氟苯甲酰氯的合成

本文介绍了抗生素类药物环丙沙星的关键中间体2,4-二氯-5-氟苯甲酰氯的各种合成方法,包括最佳工艺条件和收率。从操作步骤简单、环保和收率较高的角度,比较了各自的优缺点。并对其合成工艺提出了合理的改进意见。

2,4-二氯甲苯液相氧气氧化制2,4-二氯苯甲酸

由乙酸钴、乙酸锰、溴化物催化氧气氧化 2 ,4 二氯甲苯制备 2 ,4 二氯苯甲酸 ,反应压力 0 8～ 1 0MPa,温度 130～ 140℃ ,产率 90 8% ,纯度 99 3% .用芳香性卤代烃和戊酸的混合物做溶剂 。

(3aR,6aS)-1,3-二苄基四氢-4H-呋喃并[3,4-d]咪唑-2,4(1H)-二酮的转化利用

在(+)-生物素的不对称全合成工艺中产生的副产物(3aR,6aS)-1,3-二苄基四氢-4H-呋喃并[3,4-d]咪唑-2,4(1H)-二酮(2),经过开环酯交换、两次氧化和水解即可方便地转化得到合成(+)-生物素的关键中间体顺-1,3-二苄基-4,5-二羧基-2-咪唑烷酮,总收率74%,实现了副产物的循环利用。

铜(Ⅱ)盐催化2,4,6—三溴间甲苯酚聚合反应动力学研究

研究了各种条件下铜(Ⅱ)盐催化2,4,6—三溴间甲苯酚聚合反应的动力学.当[CuCl_2]<0.05mol/L时,r-(k_1k_2)/(k-1)[2,4,6—三溴间甲苯酚][CH_3ONa][CuCl_2];当[CuCl_2>0.05mol/L时,γ=(k_1k_2)/(k-1)[2,4,6 —三溴间甲苯酚][CH_3ONa][0.10-[CuCl_2]);实验所得的速度方程式与铜(Ⅱ) —酚氧配合物中间体形成机理相一致.决定反应速度步骤为2,4,6—三溴间甲苯酚钠与铜(Ⅱ)盐配合物的反应,并且由实验求得了反应速度常数及反应的活化能.

Enhanced catalytic oxidation of 2,4-dichlorophenol via singlet oxygen dominated peroxymonosulfate activation on CoOOH@Bi_(2)O_(3)composite

Cobalt oxyhydroxide(CoOOH)has been turned out to be a high-efficiency catalyst for peroxymonosulfate(PMS)activation.In this study,CoOOH was loaded on bismuth oxide(Bi_(2)O_(3))using a facile chemical precipitation process to improve its catalytic activity and stability.The result showed that the catalytic performance on the 2,4-dichlorophenol(2,4-DCP)degradation was significantly enhanced with only 11 wt%Bi_(2)O_(3)loading.The degradation rate in the CoOOH@Bi_(2)O_(3)/PMS system(0.2011 min−1)was nearly 6.0 times higher than that in the CoOOH/PMS system(0.0337 min−1).Furthermore,CoOOH@Bi_(2)O_(3)displayed better stability with less Co ions leaching(16.4%lower than CoOOH)in the PMS system.These phenomena were attributed to the Bi_(2)O_(3)loading which significantly increased the conductivity and specific surface area of the CoOOH@Bi_(2)O_(3)composite.Faster electron transfer facilitated the redox reaction of Co(III)/Co(II)and thus was more favorable for reactive oxygen species(ROS)generation.Meanwhile,larger specific surface area furnished more active sites for PMS activation.More importantly,there were both non-radical(^(1)O_(2))and radicals(SO_(4)^(−)•,O_(2)^(−)•,and OH•)in the CoOOH@Bi_(2)O_(3)/PMS system and^(1)O_(2)was the dominant one.In general,this study provided a simple and practical strategy to enhance the catalytic activity and stability of cobalt oxyhydroxide in the PMS system.

电-Fenton氧化降解2,4-二氯酚

以气体扩散电极为阴极,以Ti/SnO2-Sb2O5-IrO2为阳极,构建了电-Fenton氧化系统降解水中2,4-DCP(2,4-二氯酚),在考察气体扩散阴极产生H2O2适宜电位基础上,研究了初始c(Fe2+)和电化学反应时间对2,4-DCP降解的影响以及反应过程中c(H2 O2)、c(Fe2+)和ρ(Cl-)的变化.结果表明:该方法联合了电-Fenton氧化和钛基氧化物阳极氧化2种作用共同降解2,4-DCP,在阴极电位为-0.7 V、c(Fe2+)为0.15 mmol/L、反应60 min时,2,4-DCP去除率为89.1%;反应120 min时,2,4-DCP的吸收特征峰完全消失,去除率达到100%;反应240 min时,ρ(TOC)降至9.15 mg/L,去除率达79.4%.反应体系中ρ(H2O2)与ρ(Fe2+)呈负相关.2,4-DCP被降解后,其苯环上的氯主要以Cl-的形式存在于溶液中.

2,4-二氯苯酚的电化学氧化降解反应研究

采用循环伏安法和原位红外光谱技术研究了2,4-二氯苯酚在Pt电极上的电化学氧化降解反应,结合Fukui函数值预测了2,4-二氯苯酚在电化学氧化过程中的反应位点.结果表明,Pt电极对2,4-二氯苯酚有良好的电催化活性,2,4-二氯苯酚在电极表面反应主要有3个途径:直接通过电化学反应脱去氯离子,生成苯酚;在·OH的进攻下,C—Cl键断裂,4位Cl较2位Cl先脱去,生成苯二酚,并可进一步氧化生成苯醌以及不饱和羧酸;在·OH的进攻下发生苯环开环反应,生成含氯不饱和羧酸.在1700 mV左右,2,4-二氯苯酚可经电化学氧化生成CO2.

纳米零价铁活化过硫酸钠降解2,4-二氯苯酚

采用纳米零价铁(nZVI)活化过硫酸钠产生强氧化性的硫酸根自由基(SO-4·)去除目标污染物2,4-二氯苯酚(2,4-DCP).通过比较nZVI与Fe2+催化S2O2-8对2,4-DCP的降解,结合SEM、EDS对nZVI反应前后表面结构变化分析发现,nZVI在过硫酸盐氧化降解2,4-DCP中主要起到Fe2+离子源的作用,也具有还原和吸附作用.深入研究不同因素(初始pH值、nZVI投加量、S2O2-8初始浓度、2,4-DCP初始浓度)对2,4-DCP降解的影响,结果表明降低溶液初始pH值能提高nZVI/S2O2-8对2,4-DCP的降解率.在2,4-DCP初始浓度为30 mg·L-1,S2O2-8浓度为12.5 mmol·L-1,nZVI为2.0 g·L-1,pH值为3.0,温度为30℃下,2,4-DCP的去除率能达到92.1%,其降解过程符合准一级动力学,表观活化能为91.48 kJ·mol-1,是表面控制过程.

UV-H_2O_2系统对水中2,4-二氯酚氧化降解研究

研究了用UV-H2O2体系对水中2,4-二氯酚氧化降解。结果表明,UV-H2O2体系中H2O2的投加量主要由UV光强度和有机物初始浓度来确定,酸性和中性条件下有利于UV-H2O2体系对2,4-二氯酚的降解;最佳反应温度在20～25℃;UV-H2O2光氧化技术适用于低浊度水的深度处理,降解效果以浊度6 NTU为分界点。在Fenton试验中,向质量浓度为20mg/L的2,4-二氯酚溶液加入2.0mg/L的Fe2+,同时把H2O2的投加量减为0.204mg/L,pH值3.0左右,此时UV-H2O2-Fenton体系对2,4-二氯酚的氧化效率大大提高,比单纯Fenton体系的降解率提高1倍,达到95.6%。用UV-Fenton体系去除有机污染物在效果和经济上均具有明显的优越性。

Fenton试剂氧化法修复2,4-二氯酚污染土壤的研究

在泥浆体系中采用Fenton试剂氧化法修复2,4-二氯酚(2,4-DCP)污染的土壤。在恒温、避光条件下,研究2,4-DCP在泥浆体系中的解吸作用,并考察过氧化氢、硫酸亚铁、pH值、水土比、磷酸二氢钾、腐殖酸(HA)等因素对2,4-二氯酚去除效率的影响。试验结果显示,2,4-DCP在泥浆体系中有较高的解吸速率;2,4-DCP的解吸效率与水土比有关,水土比越大,解吸效率越高。研究表明:Fenton试剂氧化法能够有效地去除土壤中的2,4-DCP,过氧化氢和铁的最佳质量比为5:1,最佳pH值范围为2-3;水土比越大,2,4-DCP的去除效果越好;在pH=3时,磷酸二氢钾浓度、腐殖酸投加量和催化剂种类对2,4-DCP的去除效率影响很小。

1,2,4-噁二唑类含能化合物研究进展

1,2,4-噁二唑类含能化合物是近年来逐渐发展起来的一类新型含能材料,具有高密度、高氧平衡以及不敏感的特点。综述了关于单-1,2,4-噁二唑类、偶氮基-1,2,4-噁二唑类以及联-1,2,4-噁二唑类等三十余种含能化合物的最新合成研究成果,对部分化合物的性能进行了阐述,并结合1,2,4-噁二唑类含能化合物的性能特点,指出基于1,2,4-噁二唑环结构发展新型无卤氧化剂是较具潜力的发展方向。