亲水性p-乙酰氨基酚树脂对茶碱的吸附性能

用氯球和p-乙酰氨基酚合成了亲水性p-乙酰氨基酚树脂(简记为GQ-01),研究乙酰氨基和酚羟基两类氢键作用位点修饰的GQ-01树脂对茶碱的吸附性能。实验表明:在相同茶碱起始浓度下,GQ-01树脂对茶碱的吸附量是XAD-4商业树脂对茶碱吸附量的1.9倍;GQ-01树脂对茶碱的吸附为放热、自发的过程;GQ-01树脂对茶碱的吸附动力学数据符合Lagergren一级速率方程,颗粒内扩散是吸附速率的主要控制步骤,GQ-01树脂对茶碱的吸附动力学可采用HSDM模型加以描述;GQ-01树脂对茶碱的动态吸附及脱附实验表明GQ-01树脂对水溶液中茶碱的饱和吸附量达到102.13mg/mL,树脂可以通过80%C2H5OH和1mol/L HCl的混合溶液再生。     

邻硝基苯甲醚生产废水预处理工艺的研究

采用"酸化-树脂吸附"法对邻硝基苯甲醚生产废水进行预处理研究。比较了XAD-4、NDA-88、NDA-99、NDA-150几种树脂对酸化后废水中邻硝基苯酚的静态吸附行为,并选用吸附量较大的NDA-150树脂对该废水进行了吸附及脱附研究。结果表明,pH为4时,NDA-150树脂的平衡吸附量4.38mmol/g。动态吸附处理量为40BV(树脂体积)时,酚去除率95%,以8%NaOH为脱附剂,温度333K,脱附率98%。该工艺CODCr总去除率92%,邻硝基苯酚总去除率99%,每升废水可回收邻硝基苯酚10.8g,纯度大于97%。     

大孔树脂对对硝基苯胺的吸附行为及其应用研究

研究了溶液中无机盐、pH值对氨基修饰超高交联大孔树脂NDA-99、氧修饰超高交联大孔树脂NDA-150和大孔树脂XAD-4吸附对硝基苯胺的影响。结果表明,无机盐对吸附影响不大;NDA-99、NDA-150在中性范围吸附量最大,XAD-4的吸附量随pH增大而增大;3种树脂的吸附等温线都能很好的利用Freundlich方程进行拟合,吸附皆为放热反应且为优惠吸附;3种树脂的饱和吸附量大小依次为NDA-150>NDA-99>XAD-4。依据上述结论,采用NDA-150处理对硝基苯胺生产母液废水,每批次处理量为40BV,废水中对硝基苯胺浓度由2130mg/L降至9.6mg/L,去除率达99.5%,吸附后的树脂采用95%的乙醇可完全再生,高浓度对硝基苯胺乙醇再生溶液经蒸馏可回收对硝基苯胺和脱附剂,实现了废水治理与资源化的统一。     

酚羟基修饰的超高交联聚苯乙烯树脂对苯酚吸附及脱附性能的研究

对超高交联聚苯乙烯树脂进行酚羟基修饰得到修饰后的超高交联聚苯乙烯树脂(JN-2),将该树脂与大孔吸附树脂(Amberlite XAD-4)和超高交联树脂(NDA-150)在水溶液中对苯酚进行吸附-脱附性能比较,经过酚羟基修饰的超高交联聚苯乙烯树脂(JN-2)对苯酚的吸附性能有所提高,同时脱附性能明显改善,该树脂可望在含酚废水治理中得到广泛应用.     

氨基吡啶修饰的高交联树脂合成与吸附性能

以氯球为原料,二氯乙烷为溶剂,FeCl_3为催化剂,利用Friedel-Crafts反应制备甲苯超高交联树脂,测其氯含量为6.38%。为降低氯含量和提高吸附性能,采用2-氨基吡啶对该高交联树脂进行化学修饰,获得的高交联树脂(记为GQ-08)氯含量下降为1.36%,然后详细研究了GQ-08对水杨酸的吸附性能。实验结果表明,GQ-08在p H 2.75时对水杨酸的吸附容量最大,达到310.7 mg·g~(-1);GQ-08对水杨酸的吸附是放热过程,吸附等温线服从Freundlich方程;当溶液中NaCl含量由0%到2%变化时,GQ-08对水杨酸的吸附量明显减少,说明氯离子与水杨酸存在竞争吸附作用,增加盐度不利于水杨酸吸附。因此,在利用GQ-08树脂进行水杨酸富集分离或处理生产废水回收水杨酸时应优先考虑酸度、盐度等工艺参数。     

复合功能吸附树脂对2,4-二硝基苯酚的吸附特性

研究了NDA-99复合功能吸附树脂对2,4-二硝基苯酚的吸附及脱附行为.结果表明,该树脂对2,4-二硝基苯酚的吸附与脱附效果较好.在283-313K和研究的浓度范围内,吸附行为符合Freundlich和Langmuir等温式,该树脂对2,4-二硝基苯酚的动态吸附量为161.8mg/g.用质量分数为10%NaOH溶液作脱附剂,温度333K,体积为5BV(床体积)时,脱附率为96.7%,树脂可反复使用,并回收2,4-二硝基苯酚.     

大孔树脂对磺酸类化合物吸附行为的研究

用4种大孔树脂ND-022，ND-900，NDA-99和NDA-100作为吸附剂，分别对水溶液中甲基磺酸钠、苯磺酸钠、对甲基苯磺酸钠和2-萘磺酸钠等磺酸盐进行吸附．探讨了溶液的初始pH值对不同类型树脂吸附磺酸类物质的影响，并通过动态吸附实验研究了SO4^2-对树脂吸附磺酸盐的影响．实验结果表明，复合功能树脂NDA-99对磺酸类化合物具有良好的吸附性能，且其选择性优于弱碱树脂ND-900，这为进一步研究大孔树脂对磺酸类物质的吸附机理和实际工业应用提供了一定的理论依据。     

两种吸附树脂对4B酸吸附行为的比较研究

研究了新型复合功能吸附树脂NDA-99和超高交联大孔吸附树脂JX-101对水溶液中4B酸(对甲苯胺-2-磺酸)的静态吸附行为和热力学特性，结果表明，NDA-99树脂对4B酸的吸附量明显大于JX-101树脂，两种树脂对4B酸的吸附均符合Freundlich吸附等温方程．其中，JX-101对4B酸的吸附属于物理吸附：NDA-99由于树脂表面存在弱碱性官能团，对4B酸的吸附表现为物理吸附和化学络合协同作用。     

2-氨基吡啶修饰的聚苯乙烯树脂对2,4-D的吸附性能

氯甲基聚苯乙烯和2-氨基吡啶发生亲核取代反应,合成2-氨基吡啶修饰的聚苯乙烯树脂(简记为JX-08),以XAD-4树脂为参照,研究JX-08树脂对水溶液中2,4-D的吸附性能。实验结果表明,JX-08树脂在较宽的pH值范围(pH值在2~11)对2,4-D的吸附量大,XAD-4树脂在pH值小于2时对2,4-D的吸附量大;JX-08树脂对2,4-D的吸附符合Freundlich方程模型,XAD-4树脂对2,4-D的吸附符合Langmuir方程模型;当2,4-D流出液浓度为上样浓度的1%时,JX-08树脂和XAD-4树脂对2,4-D的吸附量分别为148.2mg/mL和40.5mg/m L。JX-08树脂和XAD-4树脂吸附的2,4-D可分别用6.5BV 2mol/L NaOH和6.5BV C2H5OH解吸。吸附机理表明,XAD-4树脂吸附2,4-D以疏水作用为主要推动力,而JX-08树脂对2,4-D的吸附存在阴离子交换和疏水作用,且阴离子交换对JX-08树脂吸附2,4-D的贡献大于疏水作用对JX-08树脂吸附2,4-D的贡献。     

氨基酸螯合吸附树脂对苯酚的吸附行为研究

合成了一种L-酪氨酸修饰的螯合吸附树脂(AJS-02),并与超高交联树脂NDA-150作对比,研究了其对苯酚的吸附和脱附行为.静态实验结果表明,在研究的浓度范围内,吸附平衡数据符合Langmuir等温吸附方程且吸附为放热过程.溶液的初始浓度为100 mg/L、吸附温度为288 K时,苯酚在AJS-02和NDA-150上的平衡吸附量分别为76.98和91.97 mg/g,苯酚在两种树脂上的吸附是比表面积和表面官能团共同作用的结果.动力学数据表明吸附动力学符合液膜扩散方程和颗粒内扩散方程,液膜扩散为吸附速率的主要控制步骤.动态吸附-脱附实验表明,AJS-02树脂对苯酚的动态穿透吸附量和饱和吸附量分别为5.26×10-2和6.60×10-2mmol/mL,采用95%乙醇作脱附剂,脱附率可达91.5%以上.     

α-Amino acid derived enaminones and their application in the synthesis of N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates and other heterocycles

A new and simple synthesis of novel N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates, which exist in equilibrium with their 4-oxo tautomers, has been developed in two steps starting from N-protected α-amino acids. The key intermediates are enaminones, which can also be isolated, characterized, and used for the construction of other functionalized heterocycles, before they spontaneously decompose to pyrrole products. 4-Hydroxypyrroles are prone to partial aerial oxidation but can be efficiently alkylated or reduced to stable polysubstituted pyrrolidine derivatives.     

Specific intramolecular aromatic CH insertion of diazosulfonamides

The chemoselectivity in the intramolecular CH insertion of various diazosulfonamides has been experimentally studied. The results reveal that the aliphatic 1,4-, 1,5-, or 1,6-C(sp³)?H insertions of diazosulfonamides are not accessible, while the aromatic 1,5-C(sp²)?H insertion can be realized specifically by adjusting the diazo-adjacent group. In addition, the general chemoselectivities in the intramolecular CH insertions of diazosulfonyl compounds are summarized. Generally, diazosulfones undergo both aromatic 1,5-C(sp²)?H and aliphatic 1,5- and 1,6-C(sp³)?H insertions, while diazosulfonates undergo aliphatic 1,5- and 1,6-C(sp³)?H insertions. However, diazosulfonamides only undergo aromatic 1,5-C(sp²)?H insertion.     

N-Heterocyclic carbene-palladacyclic complexes: synthesis,characterization and their applications in the C-N coupling and α-arylation of ketones using aryl chlorides

N-Heterocyclic carbene-palladacyclic complexes 3 were successfully achieved in a one-pot procedure under mild conditions. The structure of 3a was unambiguously confirmed by X-ray single crystal diffraction and it was an active catalyst in the Buchwald-Hartwig amination and α-arylation of ketones even at very low catalyst loadings (0.01?mol%).     

Iodine-mediated oxidative Pictet-Spengler reaction using terminal alkyne as the 2-oxoaldehyde surrogate for the synthesis of 1-aroyl-β-carbolines and fused-nitrogen heterocycles

An efficient iodine-mediated oxidative Pictet-Spengler reaction in dimethyl sulphoxide (DMSO) using terminal alkynes as the 2-oxoaldehyde surrogate for the synthesis of aryl (9H-pyrido[3,4-b]indol-1-yl)methanones is described. The scope of the protocol includes the total synthesis of Fascaplysin, Eudistomins Y₁ and Y₂. The methodology is extended for preparing pyrrolo[1,2-a]-quinoxaline and indolo[1,5-a]quinoxaline derivatives. The utility of 1-aroyl-β-carbolines was demonstrated by performing palladium-catalyzed β-carboline directed ortho-C(sp2)-H functionalization of the phenyl ring with thiomethyl (SMe) group using DMSO as source and for accessing 4-aryl-canthin-6-ones.     

Facile synthesis of bicyclic 1-arylpyrazol-5-ones

In this Letter, we described a facile method for constructing fused bicyclic 1-arylpyrazol-5-one ring system. We employed various methylene-containing carboxylic acids as the substrates and proved that the pyrazolone ring closure requires activated methylene group in intermediate II. Accordingly, a series of structurally diversified, fused bicyclic 1-arylpyrazol-5-ones was prepared in moderate to high yields using the requisite substrates.     

A carbanion induced synthesis of highly congested pyrazole and imidazole containing heterocycles

An efficient approach to the synthesis of highly congested di, penta and hexacyclic pyrazoles as well as imidazole fragment containing novel heterocyclic molecule has been developed through a carbanion induced transformation of suitably functionalized 2H-pyran-2-ones, benzo[h]chromene and thiochromeno[4,3-b]pyrans. Due to the presence of fluorescence, we report their prime application metal sensor as off/on switching in ferric ions.     

Synthesis of pyrrolo[1,2-a]pyrazines and pyrazino[1,2-a]indoles by Curtius reaction in Morita-Baylis-Hillman derivatives

Synthesis of substituted pyrrolo[1,2-a]pyrazines and pyrazino[1,2-a]indoles from the Morita-Baylis-Hillman derivatives of acrylates via saponification followed by Curtius reaction is described.     

正丁胺对激光染料荧光谱影响的研究

用正丁胺作为碳源,采用射频辉光放电制备碳膜,选用激光染料R6G和聚乙二醇混合液作为蒸气源,采用单源热蒸发,在蒸发室与染料同时沉积得到混合膜,用拉曼光谱和红外光谱分析了碳膜的结构和键合方式,分析表明:碳膜中存在胺基团和氢原子.混合膜的荧光谱测量结果表明,认为正丁胺对染料荧光谱的影响是因为胺基和氢原子的存在.     

Selective synthesis of 4,5-dihydroimidazo- and imidazo[1,5-a]quinoxalines via modified Pictet–Spengler reaction

An efficient tandem approach for the selective synthesis of 4,5-dihydroimidazo[1,5-a]quinoxalines 6a–g and imidazo[1,5-a]quinoxalines 7a–h by the reaction of 2-imidazolyl anilines 4a–c with aryl aldehydes 5a–k under mild reaction conditions is described. Introduction of electron releasing alkyl groups in substrates 4a–b was found to be instrumental for the success of the reaction.     

Understanding the Diels-Alder reactivity of 1,2-azaborine analogues

The Diels-Alder reactivity of 1,2-heteroborines (H₄C₄B(H)X, X?=?NH, PH, AsH; O, S, Se) has been computationally explored by means of Density Functional Theory (DFT) calculations. The influence of the HB?=?X fragment on the reactivity of the system has been quantitatively analyzed in detail by means of the so-called Activation Strain Model (ASM) of reactivity. It is found that the interaction between these species and the dienophile is significantly stronger than that computed for their all-carbon isoelectronic counterpart, benzene. In addition, the strain energy plays a key role in the observed reactivity trends. The role of the aromaticity strength of these heteroarenes on the reactivity is also assessed.