石棉尾矿酸浸渣作为一种吸附剂去除水溶液中的Co(Ⅱ)（英文）

本文采用XRD、FT-IR、SEM和BET等手段分别对石棉尾矿、石棉尾矿酸浸渣,以及煅烧的石棉尾矿酸浸渣进行表征。利用煅烧的石棉尾矿酸浸渣对Co(II)进行吸附研究。研究了吸附剂浓度、吸附时间、p H、离子强度和温度对Co(II)在磁性伊利石上吸附的影响,并采用Lagrange准二级动力学方程、Langmuir等温线方程、Freundlich等温线方程和D-R等温线方程对实验数据进行拟合,计算出热力学参数。结果表明,Co(II)在煅烧的石棉尾矿酸浸渣上的吸附是自发吸热过程,符合Lagrange准二级动力学方程;p H、离子强度和温度对Co(II)在煅烧的石棉尾矿酸浸渣上的吸附影响较大;热力学符合Langmuir等温线方程,并且高温利于吸附。     

改性埃洛石材料的制备及其对亚甲基蓝吸附行为的研究

使用硅烷偶联剂KH550改性埃洛石纳米管获得改性材料HNTs-APTS,并对其吸附亚甲基蓝的行为进行研究。利用傅立叶变换红外光谱仪(FTIR)、X-衍射仪(XRD)对改性前后的埃洛石进行表征。考察了吸附时间和温度对吸附过程的影响,并采用Lagrange准二级动力学方程、Langmuir等温线方程及Freundlich等温线方程对实验数据进行拟合。结果表明,KH550成功负载到埃洛石表面;改性后材料的吸附能力大大提高。改性埃洛石对亚甲基蓝的吸附约在60 min达平衡,最大吸附容量为21.66 mg/g。其吸附过程符合准二级动力学方程,热力学较好地符合Langmuir等温线方程,且吸附过程为自发吸热,升高温度有利于吸附的进行。改性材料可重复再生6次,具有良好的再生性能,可在工业处理亚甲基蓝废水中使用。     

纳米氢氧化铝-聚丙烯酰胺复合絮凝剂对镉离子的吸附研究

采用响应面法对纳米氢氧化铝-聚丙烯酰胺复合絮凝剂吸附Cd(II)过程进行了拟合和优化,分别以pH值、温度和Cd(II)浓度为自变量,研究了其对响应值镉离子最大吸附量的影响,并通过吸附动力学方程和吸附等温线数据对吸附机理进行了探讨。结果表明,采用响应面法对pH值、温度和Cd(II)浓度3个自变量进行优化后得出最大吸附量为79.07mg/g,其最优条件为:pH 6.35,镉离子浓度91.36mg/L,温度50℃;氢氧化铝-聚丙烯酰胺对Cd(II)的吸附在120min内达到平衡,且吸附动力学数据符合准二级动力学模型,表明吸附过程包含化学吸附;吸附速率的控制步骤是吸附脱附平衡步骤;吸附等温线数据与Langmuir吸附等温模型相一致,表明镉离子在氢氧化铝-聚丙烯酰胺表面形成的是单层吸附层。     

新型低成本吸附剂稻壳对Cu(Ⅱ)的去除行为研究

借助吸附动力学和吸附等温线方程,研究了稻壳对Cu(II)的去除性能,考察了流速、溶液初始pH值对动态吸附穿透曲线的影响,利用扫描电镜(SEM)表征了稻壳的表面形貌,通过红外光谱(FTIR)、X射线衍射分析(XRD)、X射线荧光光谱(XRF)探讨了Cu(II)的去除机制和途径.结果表明:吸附过程符合准二级动力学方程和Langmuir等温线方程,稻壳对Cu(II)的理论吸附容量为1.6173mg?g-1,吸附反应可以自发进行.不同操作条件下,穿透曲线的走势有一定差异.在Cu(II)的去除过程中,OH、SiO-烷基等官能团有重要作用;XRD图谱显现了纤维素的特征峰,吸附后没有发现Cu(II)的典型峰;反应完成后稻壳上检测到了Cu(II)的存在,XRF证明了吸附反应的可进行性.     

花生壳吸附水中Cr6+的研究

研究了花生壳对Cr6+吸附的动力学特点,探讨了Cr6+,初始浓度、溶液的pH值及温度对Cr6+吸附效果的影响.结果表明,在Cr6+初始浓度＜100mg/L,溶液的pH值≤2.0,温度＜40℃的操作条件下,该方法具有实际应用的可能性.此吸附过程符合Lagergren准二级动力学方程,吸附等温线符合Langmuir和Freundlich模式.     

磁性石墨烯对结晶紫的吸附性能研究

本文研究了磁性石墨烯对结晶紫的吸附特性,考察了pH、吸附剂用量、结晶紫浓度以及温度等对吸附平衡的影响。磁性石墨烯吸附结晶紫符合准二级动力学模型。不同温度下磁性石墨烯对结晶紫的吸附等温线满足Langmuir方程(R20.99)、Freundlich方程(R20.97)以及D-R模型(R20.96)。吸附热力学计算结果表明该吸附过程的△G0,并且随着温度升高△G越来越小,表明该吸附反应是自发进行的吸热反应。     

新型吸附剂偏磷酸铈对铀酰的吸附性能研究

研究新型吸附剂偏磷酸铈对铀酰离子的吸附行为。分别考察了溶液的pH值、温度、接触时间和铀酰离子初始浓度对偏磷酸铈吸附铀酰离子的影响;通过动力学、热力学以及吸附等温线初步研究了吸附机理;最后探究了共存离子和富里酸对吸附的影响。当溶液的pH值为5、温度为30℃、接触时间为60min、铀酰初始浓度为10~(-3)mol/L时为最佳吸附条件,最大吸附量可达到261.78mg/g;动力学研究表明,偏磷酸铈对铀酰离子吸附行为符合准二级动力学方程;Langmuir吸附等温线模型可以更准确的描述铀酰离子在偏磷酸铈上的吸附过程,说明此吸附过程为单分子层吸附;热力学研究表明,偏磷酸铈对铀酰离子的吸附属于吸热反应,反应自发进行,高温促进吸附行为。     

巯基功能化膨润土吸附Pb2+的动力学和热力学研究

研究了自制巯基功能化膨润土(TFB)对Pb2+的吸附行为,考察了溶液的pH值、离子强度、吸附时间和温度对吸附平衡的影响,并对吸附过程进行了动力学与热力学研究.结果表明,常温下,吸附时间为60min、0.1mol/L的KNO3、pH=6.0、5.0g/L TFB对200mg/L的Pb2+的吸附率达到85.4％以上,TFB对Pb2+的吸附动力学符合准二级动力学方程;TFB对Pb2+的吸附热力学符合Langmuir等温线方程和Dubinin-Radushkevich (D-R)等温线方程,表明吸附主要发生在TFB表面的活性区域,属于单分子层吸附,其吸附平均活化能E在8-16kJ/mol范围内,表明该吸附过程为化学吸附,不同温度下的吸附热力学的吉布斯自由能以及熵变和焓变表明该吸附过程为自发放热反应.     

（英）二氧化钛/石墨烯复合材料对水溶液中钯离子的吸附性能研究

本文合成了一种新型二氧化钛/石墨烯(TiO2-Gr)复合材料吸附剂,研究了其对水溶液中Pd(II)的吸附作用,并与TiO2的吸附性能进行了比较。制得的TiO2-Gr吸附剂分别进行了透射电子显微镜(TEM)表征及X射线衍射(XRD)分析,考察了吸附过程中时间、溶液p H、吸附剂用量、离子强度、Pd(II)浓度和温度等参数对吸附量的影响。研究了吸附过程中动力学、热力学及吸附等温线。结果表明吸附过程符合假二级动力学模型,吸附等温线符合Langmuir和Freundlich等温吸附方程。对热力学函数(吉布斯函数变、焓变、熵变)测定表明,本文合成的TiO2-Gr吸附剂对Pd(II)的吸附属于自发吸热反应。     

二氧化钛/石墨烯复合材料对水溶液中钯离子的吸附性能研究(英文)

本文合成了一种新型二氧化钛/石墨烯(TiO2-Gr)复合材料吸附剂,研究了其对水溶液中Pd(II)的吸附作用,并与TiO2的吸附性能进行了比较。制得的TiO2-Gr吸附剂分别进行了透射电子显微镜(TEM)表征及X射线衍射(XRD)分析,考察了吸附过程中时间、溶液p H、吸附剂用量、离子强度、Pd(II)浓度和温度等参数对吸附量的影响。研究了吸附过程中动力学、热力学及吸附等温线。结果表明吸附过程符合假二级动力学模型,吸附等温线符合Langmuir和Freundlich等温吸附方程。对热力学函数(吉布斯函数变、焓变、熵变)测定表明,本文合成的TiO2-Gr吸附剂对Pd(II)的吸附属于自发吸热反应。     

二氧化碳和丙烯直接合成甲基丙烯酸的NiPMo/TiO2催化剂的研究

用溶胶-凝胶法以磷钼酸(MPA)的镍盐溶液水解钛酸四丁酯制备了NiPMo/TiO2催化剂.使用ICP、 XRD、 TG-DTA、 IR、 TPD-MS和微反应技术研究了催化剂的化学组成、热稳定性、化学吸附性质和催化反应性能.杂多钼酸盐与TiO2通过O2-在TiO2表面发生了键合.在623 K下,杂多阴离子仍保持原有的Keggin结构.CO2在Lewis酸位Ni(Ⅱ)和Lewis碱位Ni-O-Mo的桥氧协同作用下生成CO2卧式吸附态Ni(Ⅱ)←O-(CO)←(O--Ni).丙烯有多种吸附态在催化剂上吸附.在563 K、 1 MPa和空速1500 h-1的反应条件下,丙烯的摩尔转化率为3.2%,产物MAA选择性为95%.     

Toward new camptothecins. Part 6: Synthesis of crucial ketones and their use in Friedländer reaction

In the context of the preparation of camptothecin and luotonin A analogs, the synthesis of some key keto-precursors and their use in Friedländer condensation are described. This paper also focuses on the stability of these keto intermediates and emphasizes the major differences between indolizinones and pyrroloquinazolinones series. Noteworthy is also the report of some original structures isolated as by-products of some experiments.     

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.     

CoFe2O4自形成磁性液体场致结构化对磁化的影响

The Langevin paramagnetic theory can’t describe the relation between magnetization of ferrofluids and applied magnetic field. The structuralization of ferrofluids, which is considered the main influence factor of the magnetization, is regarded. The part of magnetization works is deposited when the structure is forming. This action influences the magnetization of ferrofluids directly or indirectly. On the base of the “compressing” model, the Langevin function that usually describes the magnetization of ferrofluid is modified, and a well-fitted curve is obtained. An equation of the relation between the equivalent volume fraction after being “compressed” and the intensity of magnetic field is discovered, which approximately describes the process of magnetization. The relation between the approximate initial susceptibility and the volume fraction can be obtained from modified formula.     

KMnO4-mediated oxidative CN bond cleavage of tertiary amines: Synthesis of amides and sulfonamides

KMnO₄-mediated oxidative CN bond cleavage of tertiary amines producing secondary amine was introduced, which was trapped by electrophiles (acyl chloride and sulfonyl chloride) to form amides and sulfonamides. The reaction could take place at mild condition, tolerating a wide range of function groups and affording products in moderate to excellent yields.     

Highly regioselective Buchwald–Hartwig amination at C-2 of 2,4-dichloropyridine enabling a novel approach to 2,4-bisanilinopyridine (BAPyd) libraries

The highly regioselective Buchwald–Hartwig amination at C-2 of the cheap and readily accessible reagent, 2,4-dichloropyridine with a range of anilines and heterocyclic amines is described. This new methodology is robust and provides a facile access to 4-chloro-N-phenylpyridin-2-amines on 0.25 mol scale. These intermediates undergo a further Buchwald–Hartwig amination at higher temperature to enable rapid exploration of the chemical space at C-4 and to provide a library of 2,4-bisaminopyridines.     

Chemistry of heterocyclic compounds at the A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences, over 50 years (Review)

The review contains a concise historical account and information on the most significant researches undertaken by the staff at the A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences on the Chemistry of Heterocyclic Compounds. Dedicated to Academician of the Russian Academy of Sciences B. A. Trofimov on his 70th jubilee. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1443–1502, October, 2008.     

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.