水热条件下坡缕石在NaOH溶液中的行为及结构变化

分别用1,2和3 mol·L^-1的NaOH溶液,在不同的温度条件下对坡缕石进行了侵蚀实验。对反应后的固相产物进行了XRD和SEM分析,对浸出液中的金属阳离子进行了原子吸收光谱分析。讨论了反应温度和碱溶液浓度对碱溶后产物的影响。XRD和SEM结果表明,c_NaOH≤2 mol·L^-1时,坡缕石经碱溶液侵蚀后,可以生成蒙脱石和方沸石,其中反应温度的升高有利于方沸石的形成,碱溶液浓度的升高有利于蒙脱石的形成。当碱溶液浓度达到3 mol·L^-1,反应温度为200 ℃时,最终产物为SiO₂。浸出液的定量分析结果显示,坡缕石与碱溶液的反应过程中,Na⁺对八面体阳离子的置换具有选择性,置换顺序为：Al³⁺＞Fe³⁺(Fe²⁺)＞Mg²⁺。     

溶胶凝胶模板法制备SiO2∶Sm3+纳米阵列材料

采用溶胶凝胶模板法制备了不同Sm³⁺掺量的SiO₂∶Sm³⁺纳米阵列材料,通过SEM、EDS、FTIR等对材料的形貌和结构进行测试表征。FTIR分析表明Sm³⁺进入SiO₂网络结构形成了Si-O-Sm键。SEM、EDS分析显示Sm³⁺掺量的增大促使阵列由纳米管向纳米线的转变。此外,腐蚀清洗等后处理工艺对保持纳米阵列的形貌至关重要。最后,讨论了溶胶凝胶模板法制备SiO₂∶Sm³⁺纳米阵列的机理。     

芳基四硫富瓦烯与碘电荷转移复合物的合成及其晶体结构

采用缓慢挥发溶剂的方法合成了硫原子桥联芳基取代四硫富瓦烯（Ar-S-TTF）与碘的3种电荷转移复合物（1^+·）（I₃）·I₂、（2^+·）（I₅）·I₂和（3²⁺）（I₃）₂,采用单晶X射线衍射、紫外可见光谱、循环伏安对其进行了表征。复合物（1^+·）（I₃）·I₂为C2/c空间群,1^+·呈椅式构型。化合物1与碘之间在溶液中和复合物中电荷转移一致。复合物（2^+·）（I₅）·I₂为P1空间群,2^+·呈椅式构型。复合物（3²⁺）（I₃）₂为Pbca空间群,3²⁺呈独特的平面构型。化合物2和3与碘之间在溶液中和复合物中呈现不同的电荷转移。复合物中聚碘阴离子呈现不同的堆积结构：由I₃^-或I₅^-/I₂组成的一维链状和I₃^-/I₂组成的二维网格状。     

八羧基铜酞菁修饰海藻酸钠阳膜层制备CuPc(COOH)8-SA/mCS双极膜及其表征

在海藻酸钠(SA)中添加八羧基铜酞菁(CuPc(COOH)₈),并分别用Fe³⁺离子和戊二醛作为交联剂对海藻酸钠-八羧基铜酞菁阳膜层和壳聚糖(CS)阴膜层进行改性,制备了八羧基铜酞菁-海藻酸钠/改性壳聚糖双极膜(CuPc(COOH)₈-SA/mCS BPM)。在海藻酸钠中添加八羧基铜酞菁以促进中间层中水的解离。用FTIR、SEM等对制备的CuPc(COOH)₈-SA/mCS双极膜进行了表征。作为比对,制备了Fe³⁺离子改性的Fe-SA/mCS双极膜和二茂铁(Fc)离子改性的Fc-SA/mCS双极膜。实验结果表明,CuPc(COOH)₈-SA阳离子交换膜的离子交换容量、H⁺离子透过率均获得提高。与Fe³⁺离子改性或二茂铁离子改性的mSA/mCS双极膜相比,CuPc(COOH)₈-SA/mCS双极膜的阻抗、电阻压降(IR降)和溶胀度降低,在H+离子浓度低于8 mol·L^-1的酸溶液中具有稳定的工作性能。     

螯合树脂研究 Ⅻ.以聚硫醚为主链的异丙巯基胺树脂的合成及其吸附性能

 由聚环硫氟丙烷与多乙烯多胺反应制得的聚合物(PB)再与环硫丙烷反应,合成了四种以聚硫醚为主链的异丙巯基胺树脂(PBM_1-4)。树脂对Au³⁺、Pd²⁺、Pt⁴⁺、Ag⁺和Hg²⁺等离子具有强的吸附能力,对Cu²⁺次之,对Zn²⁺和Pb²⁺很弱。树脂对贵金属具有高的选择性,能从含Au³⁺、Cr³⁺、Co²⁺、Ni²⁺、Cu²⁺、Mn²⁺、Zn²⁺和Fe³⁺的溶液中定量吸附Au³⁺而不吸附其它离子。     

阳离子(从有机铵到无机阳离子)对fac-[Fe(CO)3I3]-阴离子的稳定性和毒性的调节

通过无机碘盐(MI_n)与 cis-[Fe(CO)₄I₂]反应制备了 5 个盐类化合物 fac-M[Fe(CO)₃I₃]_n (Mⁿ⁺=Na⁺ (1),K⁺ (2),Mg²⁺ (3),Ca²⁺ (4),NH₄⁺ (5)),探讨了阳离子Mⁿ⁺对fac-[Fe(CO)₃I₃]^-阴离子的稳定性和细胞毒性的影响。通过傅里叶变换红外光谱(FTIR)监测,发现盐 1~5在 DMSO、D₂O、生理盐水等介质中均能缓释 CO,其释放动力学符合一级反应动力学模型;还发现溶液中碘离子的浓度和酸度对该阴离子的缓释CO性能也具有调节作用。通过噻唑蓝(MTT)实验评估了盐1~5对膀胱癌细胞的毒性,其24 h半抑制浓度(IC₅₀)在 25~43 μmol·L^-1。与有机铵阳离子类的盐化合物相比,盐1~5在含水介质中的释放 CO速率下降,毒性亦有下调。研究还发现这类fac-[Fe(CO)₃I₃]^-阴离子在缓释CO的同时释放碘自由基,并能导致线粒体活性氧(ROS)水平、Parkin蛋白表达均上调。铁死亡抑制剂(Ferrostatin-1和Liproxstatin-1)试验结果表明这类化合物可能引发铁死亡通路并促进肿瘤细胞死亡。     

Ca2+-Mg2+-Zn2+体系在水溶性聚磷酸铵溶液中螯合规律的研究

近年来,水溶性聚磷酸铵在液体肥料和复合肥料的领域受到了广泛的关注,并在发达国家中得到了大面积的推广及应用。在pH值为5.5~8.0、温度为278.15 K~323.15 K的条件下,本文采用滴定法研究Ca_²⁺-Mg_²⁺-Zn_²⁺体系在聚磷酸铵溶液中的螯合规律。实验结果表明：相同质量分数的聚磷酸铵溶液对金属离子的螯合量会随着体系中Ca_²⁺、Mg_²⁺、Zn_²⁺的摩尔浓度的变化而变化;随着温度的升高而逐渐降低;随着pH的增加而逐渐增加;随着聚合度的升高而逐渐增加。采用傅里叶红外光谱对聚磷酸铵和A₁B₃C₃体系的螯合物进行表征。     

两个3d-4f杂核配合物[Fe(phen)3]2[FeLn(H2O)(tiron)3]·6H2O的合成、晶体结构和磁性(Ln=HoⅢ, YbⅢ)

Ln₂O₃、硝酸铁、邻菲罗啉和钛铁试剂(tiron)通过水热法自组装合成了2个异质同晶的3d-4f杂核配合物[Fe(phen)₃]₂[FeLn(H₂O)(tiron)₃]·6H₂O, 其中, Ln=Ho^Ⅲ (1)和Yb^Ⅲ (2)。X-射线单晶衍射分析表明, 晶体属立方晶系, P2₁3空间群。3个tiron^4-配体利用酚氧桥联Ln³⁺和Fe³⁺形成具有C₃对称性的[FeLn(H₂O)(tiron)₃]^6-异双核配位单元, 其中七配位的Ln³⁺呈现一种畸变的单帽反三棱柱配位构型。配阳离子[Fe(phen)₃]³⁺通过phen-phen之间的π-π相互作用和与配阴离子间的静电引力等作用组装成三维的超分子。在2~300 K温度范围内测试了配合物的变温磁化率, 结果表明, Ln(Ⅲ)-Fe(Ⅲ)之间存在反铁磁性相互作用。     

CuY制备方法对其催化甲醇氧化羰基化活性中心的影响

以Cu(NO₃)₂为铜源,以NaY和HY分子筛为载体,通过溶液离子交换法和等体积浸渍法制备了不同的无氯CuY催化剂,并进行了气相甲醇氧化羰基化催化活性研究。通过浸渍法制备的催化剂Cu含量为10%,而以NaY和铜氨溶液离子交换制备的催化剂Cu含量只有6.3%,但其催化活性和选择性均较好。通过催化剂的Cu元素分析、低温氮吸附-脱附、XRD、H₂-TPR、XPS和TPD等表征表明,溶液离子交换法制备的催化剂,Cu物种以离子的形式高度分散于分子筛骨架结构中,较好地保持了分子筛晶体结构,并对甲醇有较强的吸附能力,催化活性较高,而将等体积浸渍Cu(NO₃)₂溶液后的HY或NaY分子筛,在400 ℃焙烧过程中,发生了固体离子交换反应,形成了连接于分子筛骨架的Cu²⁺,但以HY为载体更容易进行固体离子交换,未交换的铜物种以CuO的形式分散到分子筛表面。在600 ℃高温活化中,催化剂中Cu²⁺可部分还原为活性物质Cu⁺,但以NaY和铜氨溶液离子交换制备的催化剂Cu²⁺自还原能力最大。     

SILAR法制备化学计量CuInS2薄膜

在室温下，以不同c_Cu/c_In的CuCl₂和InCl₃混合溶液作为阳离子前驱体，Na₂S水溶液为硫源，利用连续离子层吸附反应法(SILAR)在玻璃基底上制备了CuInS₂薄膜。XRD结果表明，当c_Cu²⁺/c_In³⁺在1～1.5范围内均可形成具有黄铜矿结构的CuInS₂薄膜。SEM观察到随c_Cu²⁺/c_In³⁺的升高，薄膜表面颗粒长大并出现团簇聚集。通过XPS测定薄膜表面的化学组成证明当c_Cu²⁺/c_In³⁺=1.25时，CuInS₂薄膜接近其标准的化学计量组成。此时薄膜的吸收系数大于>10⁴ cm^-1，禁带宽度E_g为1.45 eV。     

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.