In(Ⅲ)-1-苯基-3-甲基-4-噻吩甲酰基-吡唑啉酮-5配合物吸附波的研究

在pH3.0的HCl-NaAc介质中,In(Ⅲ)与1_苯基_3_甲基_4_噻吩甲酰基_吡唑啉酮_5(HPMTHP)生成配合物,于-0.63V(vs.SCE)处出现一尖锐、灵敏的极谱峰,In含量在0.002～1μg/mL范围内与峰高呈线性关系。用多种电化学方法研究了极谱波的性质及反应机理,证明-0.63V处的极谱波为配合物吸附波,峰电流由中心离子In(Ⅲ)还原产生。用直线法测得配合物组成为n[In(Ⅲ)]∶n(HPMTHP)=1∶1,表观稳定常数为2.96×103。     

Sn(Ⅳ)-甘露醇-邻苯三酚红-CTMAB四元体系光度法测定铜合金中微量锡

在溴化十六烷基三甲基铵(CTMAB)存在下,Sn(Ⅳ) 同甘露醇和邻苯三酚红在pH 0.8时形成紫红色的四元配合物,配合物的组成为: n(Sn(Ⅳ))∶n(甘露醇)∶n(邻苯三酚红)∶n(CTMAB)=1∶1∶2∶1,配合物的最大吸收波长为535 nm,Sn(Ⅳ)在0～3.0 μg/mL范围内符合比耳定律,摩尔吸光系数为3.0×105 L·mol-1·cm-1.体系不需要分离可直接用于铜合金中微量锡的测定.     

N, N′-二吡啶基-3-亚甲基-1, 2-乙二胺-稀土硝酸盐配合物的合成与表征

在乙腈溶液中合成了N,N′-二吡啶基-3-亚甲基-1,2-乙二胺(L)的稀土硝酸盐系列配合物.利用元素分析、 红外光谱和差热-热重分析等手段对所合成的配合物进行了表征,结果表明合成的配合物都符合稀土金属离子与配体为1∶1的化学计量比,其组成可表示为[RE(NO3)3L]·nH2O [RELa(Ⅲ),Nd(Ⅲ),Eu(Ⅲ),Tb(Ⅲ),Er(Ⅲ),n2.5,1.5,1].另外,初步研究了其中Eu(Ⅲ)和Tb(Ⅲ)配合物在室温固体状态下的荧光性质,结果显示这两个配合物表现出相应的Eu(Ⅲ)和Tb(Ⅲ)离子的特征发射.     

分光光度法测铝电解质中的钒

研究了铝电解质中钒的测定方法,采用高温熔融样品.在4.5～6.5 mol/L HCl介质中,使V(Ⅴ)与邻苯二酚紫和乳化剂OP显色生成三元蓝色配合物,其组成为:n(钒)∶n(邻苯二酚紫)∶n(OP)=1∶2∶1,配合物最大吸收波长为580 nm,V在0～10.0 μg/10 mL范围内符合比尔定律.用分光光度法测定,回收率在96.0%～104.0%之间,相对标准偏差为6.52%～9.62%.     

“配位诱导”铕(III)/聚乙二醇-聚丙烯酸嵌段聚合物胶束的研究

研究了稀土金属铕(Ⅲ)-联吡啶(bpy)有机配合物与双亲水性两嵌段聚合物聚乙二醇-聚丙烯酸(PEO₁₁₃-b-PAA₈₂)在不同溶剂中[V(水)∶V(乙醇)＝7.5∶1, 5∶1]通过“配位诱导”作用在水中形成配合物胶束的过程. 荧光光谱结果表明Eu(Ⅲ)分别与bpy和PAA发生配位, Eu(Ⅲ)与PAA中羧基的配位使聚合物发生交联在水性溶剂中形成了配合物胶束. 用动态激光光散射(DLS), 原子力显微镜(AFM)和透射电镜(TEM)等测试方法对配合物胶束的形态及尺寸进行了表征.     

1,2-双烷基(芳基)硫代乙烷对金的萃取性质和配合物的研究

本文研究了1,2-双烷基(芳基)硫代乙烷(L)——1,2-双(正辛基硫代)乙烷(BOTE)、1,2-双(正戊基硫代)乙烷(BATE)、1,2-双(苯基硫代)乙烷(BPTE)对金的萃取及其配合物的性质.双烷基硫代乙烷对金具有很强的萃取能力,可定量地萃取金.在溶液中,当[L]≥[Au~(3 )]时,Au与L形成1∶1Au-L配合物,而在[L]<[Au~(3 )]时,则为2∶1Au-L配合物.固态时,Au(Ⅲ)、Au(Ⅰ)与L只形成2∶1配合物(AuCl_3)_2L和AaCl)_2L.讨论了BOTE和BATE与Au(Ⅲ)、Au(Ⅰ)配合物的IR和~1H NMR谱.IR谱证实了关于Au(Ⅰ)配合物为线型结构的推断,并借助金原子的交换机理,解释了配合物与配位体的~1H NMR谱外观相似的原因.详细分析了Au(Ⅲ)配合物低频区的IR数据,提出了配合物有离子型结构的新证据.     

“配位诱导”铕(III)/聚乙二醇-聚丙烯酸嵌段聚合物胶束的研究

研究了稀土金属铕(Ⅲ)-联吡啶(bpy)有机配合物与双亲水性两嵌段聚合物聚乙二醇-聚丙烯酸(PEO113-b-PAA82)在不同溶剂中[V(水)∶V(乙醇)=7.5∶1,5∶1]通过“配位诱导”作用在水中形成配合物胶束的过程.荧光光谱结果表明Eu(Ⅲ)分别与bpy和PAA发生配位,Eu(Ⅲ)与PAA中羧基的配位使聚合物发生交联在水性溶剂中形成了配合物胶束.用动态激光光散射(DLS),原子力显微镜(AFM)和透射电镜(TEM)等测试方法对配合物胶束的形态及尺寸进行了表征.     

芳羧酸功能化的聚砜与Tb(III)形成的高分子-稀土配合物的结构与荧光发射性能

通过大分子反应将苯甲酸(BA)键合在聚砜(PSF)侧链,制得芳羧酸功能化的聚砜(PSFBA).以PSFBA为大分子配基,以邻菲啰啉(Phen)为小分子配体,与Tb(Ⅲ)配位,分别制备了二元配合物PSFBA-Tb(Ⅲ)与三元配合物PSFBA-Tb(Ⅲ)-Phen,采用傅里叶变换红外(FTIR)光谱和紫外(UV)吸收光谱对配合物进行了表征,深入研究了配合物(溶液与薄膜)的荧光发射性能及热稳定性与结构的关系.研究结果表明,以PSFBA为大分子配基所形成的高分子-稀土配合物,均能发射出很强的Tb(Ⅲ)特征荧光,即键合在PSFBA侧链的配基BA能有效地敏化Tb(Ⅲ)的荧光发射.二元配合物PSFBA-Tb(Ⅲ)的表观饱和配位数为10,即当二元配合物具有PSF-(BA)5-Tb(Ⅲ)的结构时,BA对Tb(Ⅲ)的配位表观上达到饱和,此时二元配合物具有最强的荧光发射.按n(Phen):n(Tb(Ⅲ))=1的比例将Phen加入二元配合物PSF-(BA)5-Tb(Ⅲ)溶液中进行补充配位,所制备的三元配合物PSF-(BA)5-Tb(Ⅲ)-(Phen)1与惯用比例的三元配合物PSF-(BA)1-Tb(Ⅲ)-(Phen)3或PSF-(BA)1-Tb(Ⅲ)-(Phen)2相比,不仅荧光发射强度高,而且热稳定性能好,是一种高性能的场致发光材料.     

2-甲基-8-羟基喹啉-丙烯酸-镓(Ⅲ)与甲基丙烯酸甲酯共聚物的合成与表征

制备了 2 甲基 8 羟基喹啉、丙烯酸与镓 (Ⅲ )的三元配合物 ,将此配合物与甲基丙烯酸甲酯共聚后得到含镓 (Ⅲ )的共聚物 ,这种共聚物易溶于氯仿、丙酮等普通低沸点溶剂 ,具有良好的成膜性能 .用红外光谱、元素分析、紫外光谱等方法对三元配合物和共聚物的组成进行了表征 .测试三元配合物和共聚物的荧光光谱 ,表明共聚物在 4 96nm处能发出较强的荧光 .DSC和TG分析表明 ,共聚物具有良好的耐热性和热稳定性 .     

三元配合——紫外分光光度法测定钕

在pH值为5.00的NaAc-Hac缓冲体系中,Nd(Ⅲ)与7-碘-8-羟基喹啉-5-磺酸(FERRON)及溴化十六烷基三甲铵(CTMAB)反应形成三元配合物,最大吸收位于389.5 nm处,Nd(Ⅲ)浓度在0.2 ～ 4.0 mg/L范围内服从比耳定律,回归方程为ΔA=0.1205C+0.0052,r=0.9996(ΔA为试验溶液吸光度Ai与空白溶液吸光度Ao之差; C单位为mg/L Nd(Ⅲ)),表观摩尔吸收系数ε389.5=1.8×104L/(mol·cm),RSD=5.0‰(n=8),检出限为0.083 mg/L.三元配合物的组成比为Nd(Ⅲ)∶CTMAB∶FERRON=1∶2∶2.考察了20多种共存离子的影响,大多数常见离子不干扰.用于样品回收实验,结果满意.     

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%.     

Synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives

Different approaches for the synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives from simple amino acids have been investigated. A library of 33 precursors for the preparation of N-hydroxy pyrazinones was obtained in moderate to good yields.     

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.     

A general and convenient synthesis of 4-(tosylmethyl)semicarbazones and their use in amidoalkylation of hydrogen,heteroatom, and carbon nucleophiles

A general synthesis of previously unknown semicarbazone-based α-amidoalkylating reagents, 4-(tosylmethyl)semicarbazones, has been developed. The synthesis involved three-component condensation of semicarbazones of aliphatic or aromatic aldehydes with the same or other aldehydes and p-toluenesulfinic acid. The scope and limitations of this reaction were investigated. The compounds obtained were demonstrated to be an efficient α-(4-semicarbazono)alkylating agents. They were reacted with H- (sodium borohydride), O- (sodium methylate), S- (sodium phenylthiolate), N- (pyrrolidine, sodium succinimide), P- (trialkyl phosphites), and C-nucleophiles (sodium diethyl malonate) to give the corresponding products of the tosyl group substitution, 4-substituted semicarbazones, including analogues of nitrofurazone. Among the prepared compounds tested in vitro for antibacterial and antifungal activity, three nitrofuryl-containing semicarbazones exhibited high biological activities with minimum inhibitory concentration (MIC) values of 8–32 μg/mL.     

Synthesis of novel chiral bidentate hydroxyalkyl-N-heterocyclic carbene ligands and their application in palladium-catalyzed Mizoroki–Heck couplings and asymmetric addition of diethylzinc to benzaldehyde

A small library of new chiral bidentate hydroxyalkyl-imidazolium salts 1 is conveniently synthesized on multi-gram scale from inexpensive and commercially available chiral pool amino acids. The corresponding carbenes, generated by deprotonation of imidazolium salts 1, in combination with palladium(II) chloride were tested in the Mizoroki–Heck coupling reaction. The most significant results in terms of yields and reactivities were achieved with low catalyst loading. The catalytic activities of these imidazolium salts were also investigated in the asymmetric addition of diethylzinc to benzaldehyde. The use of MgO nanoparticles as an additive in conjunction with these ligands played a crucial role in increasing the efficiency of these reactions.     

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.     

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.