基于邻苯二甲酰-L-丙氨酸配体的两例Cu（Ⅱ）纯手性同质多晶配合物:合成与结构

合成了2例Cu（Ⅱ）的纯手性同质多晶[CuL₂（Phen）]（HL=邻苯二甲酰-L-丙氨酸,Phen=1,10-菲咯啉）,并对其进行了表征。X射线单晶衍射测定表明,邻苯二甲酰-L-丙氨酸在2例配合物中采取了相同的配位方式,Cu（Ⅱ）原子具有变形的八面体配位环境,分别和2个邻苯二甲酰-L-丙氨酸离子上的2个羧基氧原子,1个1,10-菲咯啉的2个氮原子配位。不同的是这2例同质多晶显示出不同的颜色,并且配合物1属于单斜晶系,C2空间群,配合物2属于正交晶系,P2₁2₁2₁空间群。配合物1通过π…π堆积作用形成一维链状结构,配合物2是简单小分子结构。此外,DFT理论研究表明,配合物1具有较低的能量,稳定性更高。     

基于邻苯二甲酰-L-丙氨酸配体的两例Cu(II)纯手性同质多晶配合物:合成与结构

合成了2例Cu（Ⅱ）的纯手性同质多晶[CuL₂（Phen）]（HL=邻苯二甲酰-L-丙氨酸,Phen=1,10-菲咯啉）,并对其进行了表征。X射线单晶衍射测定表明,邻苯二甲酰-L-丙氨酸在2例配合物中采取了相同的配位方式,Cu（Ⅱ）原子具有变形的八面体配位环境,分别和2个邻苯二甲酰-L-丙氨酸离子上的2个羧基氧原子,1个1,10-菲咯啉的2个氮原子配位。不同的是这2例同质多晶显示出不同的颜色,并且配合物1属于单斜晶系,C2空间群,配合物2属于正交晶系,P2₁2₁2₁空间群。配合物1通过π…π堆积作用形成一维链状结构,配合物2是简单小分子结构。此外,DFT理论研究表明,配合物1具有较低的能量,稳定性更高。     

Ti3C2Tx/MnO2正极在水系锌电池中的电化学性能

二氧化锰(MnO₂)材料具有比容量大、电极电位高、储量丰富以及价格低廉等优势,成为水系锌电池正极最受关注的一类材料,然而其仍然存在着结构稳定性差和电化学储存机理复杂的问题。因此,我们通过两步合成法制备了一种花苞状结构的MnO₂负载在Ti₃C₂T_x表面形成Ti₃C₂T_x/MnO₂复合材料,通过X射线粉末衍射(XRD)、X射线光电子能谱(XPS)、透射电子显微镜(TEM)和高分辨透射电子显微镜(HRTEM)对复合样品的结构、成分和形貌进行表征。通过将Ti₃C₂T_x/MnO₂复合材料作为正极,与锌负极匹配组装成水系锌电池,研究了其分别在2 mol·L^-1 ZnSO₄、2 mol·L^-1 ZnSO₄+0.1 mol·L^-1 MnSO₄、30 mol·L^-1三氟甲基磺酸四乙基铵(TEAOTf)+1 mol·L^-1三氟甲烷磺酸锌(ZnOTf)和3 mol·L^-1 ZnOTf四种电解液中的电化学性能。结果表明,Ti₃C₂T_x/MnO₂在2 mol·L^-1 ZnSO₄中的比容量较高,但循环稳定性很差。将TEAOTf盐和ZnOTf盐共溶于水中,设计了一种新型的含惰性阳离子的超高浓度盐包水电解液(30 mol·L^-1 TEAOTf+1 mol·L^-1 ZnOTf),不仅提高了Ti₃C₂T_x/MnO₂材料的可逆性,而且有效抑制了电极材料在循环过程中的溶解。     

用于痕量监测Zr4+、Cr2O72-、Fe3+、HPO42-和指纹识别的功能化Eu3+/Tb3+配位聚合物荧光探针的构筑

采用芳香族π共轭及含氮原子有机连接剂,合成同构铽、铕发光配位聚合物(CPs){[Eu(PLIA)_1.5(H₂O)₂]·H₂O}_n (1)和{[Tb(PLIA)_1.5(H₂O)₂]·H₂O}_n (2),其中H₂PLIA=5-((吡啶-4-基甲基)氧基)苯-1,3-二甲酸。对合成的配合物进行了结构测定、表征和荧光痕量识别实验研究。2个同构配合物具有理想的三维框架结构,π…π堆积及氢键等弱相互作用增强了其化学稳定性;表征显示配位聚合物1和2具有良好的荧光性质、结晶性、热力学稳定性及结构完整性,可作为荧光传感的材料。1和2对水溶液中的Zr⁴⁺、Cr₂O₇^2-和Fe³⁺、HPO₄^2-具有选择性好、灵敏度高的荧光识别能力,其检出限分别为0.139 μmol·L^-1(1,Zr⁴⁺)、0.626 μmol·L^-1(1,Cr₂O₇^2-)、0.430 μmol·L^-1(2,Fe³⁺)、1.36 μmol·L^-1(2,HPO₄^2-)。探究了1和2作为探针的荧光猝灭机理。更有趣的是,1和2具有指纹识别性能,其荧光指纹纹路清晰连贯,细节明显,可被清晰观察。     

基于一个四羧酸配体的镧系金属-有机框架材料及其对有机小分子的检测

以四羧酸3,5-双间苯二甲酸-1,2,4-三氮唑（H₄L）为配体,与镧系金属Ln（Ⅲ）盐反应,自组装合成了2个具有三维孔洞结构的镧系金属-有机框架材料（Ln-MOFs）：{[Ho₃L₂（H₂O）₆]·（OH）·2DMF}_n（1）,{[Tb₃L₂（H₂O）₆]·（OH）·2DMF}_n（2）。单晶X射线衍射分析表明,1与2属于异质同构晶体,为单斜晶系C2/m空间群。3个Ln（Ⅲ）离子通过8个羧基桥联形成三核[Ln₃（COO）₈]次级结构单元,晶体由[Ln₃（COO）₈]次级结构单元相互连接形成一维无机链,链与链之间通过配体L⁴-相连形成具有一维孔道的三维网络结构。有机小分子溶剂交换荧光研究表明,2在硝基苯溶剂中表现出荧光猝灭现象,Tb-MOF材料对硝基苯等爆炸物具有良好的荧光探测功能。     

2-氨基吡啶类双核铜(Ⅱ)配合物的合成、晶体结构及性质

分别以3-甲基-2-氨基吡啶(L₁)、5-溴-2-氨基吡啶(L₂)为配体,采用溶液法合成了2个新的双核铜配合物：[Cu₂(CH₃COO)₄(L₁)₂](1)和[Cu₂(CH₃COO)₄(L₂)₂](2),并利用熔点、红外光谱、紫外可见光谱、荧光光谱、高分辨质谱和X射线单晶衍射等手段对其进行表征。1属于正交晶系Pbca空间群; 2属于单斜晶系P2₁/n空间群。每个配合物含有2个铜中心离子、4个醋酸根离子和2个配体(L₁或L₂)分子;每个醋酸根都起到桥联作用,分别与2个Cu²⁺配位,形成笼状结构;每个Cu²⁺均为五配位变形四方锥构型。1和2对金黄色葡萄球菌、枯草芽孢杆菌、大肠杆菌显示出良好抑制作用;对DPPH·具有良好清除效果;均表现出准可逆氧化还原的电化学特性。     

CO2鼓泡法可控制备单层中空CaCO3微球:染料负载及细胞生物成像

在L-蛋氨酸（L-Met）的导向下,可控制备了一种单层中空CaCO₃微球。考察了L-Met的加入量、CO₂流速和反应温度等重要参数对CaCO₃形貌、尺度和晶相的影响。作为一种客体分子载体,该单层中空CaCO₃微球可负载罗丹明B（RhB）,得到一种发光复合材料（RhB@hollow-CaCO₃）。RhB@hollow-CaCO₃）对A-549肺癌细胞（A549 LCCs）和HO8910人卵巢癌细胞（HO8910 OCCs）表现出良好的生物相容性。     

基于2-氨基-3-羟基-吡啶Schiff碱的双核Ni(Ⅱ)和Zn(Ⅱ)配合物:合成、超分子结构和光谱性质

合成了2个2-氨基-3-羟基-吡啶Schiff碱双核Ni（Ⅱ）和Zn（Ⅱ）配合物,[Ni（L¹）（DMF）]₂（1）（H₂L¹=4-羟基-3-（（3-羟基-吡啶-2-亚氨基））-苯并吡喃-2-酮）和[Zn（L²）（H₂O）]2·2DMF（2）（H₂L²=2-（（3,5-二溴-2-羟基）-氨基）-吡啶-3-醇）,并通过元素分析、红外光谱、紫外-可见吸收光谱、荧光光谱及X射线单晶衍射分析等手段进行了表征。X射线单晶衍射分析结果表明：配合物1和2均具有双核结构,均由2个金属离子和2个配体单元以及2个配位的溶剂分子组成,不同的是配合物2含有2个溶剂分子。配合物1和2都是单斜晶系、P2₁/c空间群,且中心金属Ni（Ⅱ）和Zn（Ⅱ）离子的空间构型均为五配位的扭曲的四方锥。此外,配合物1和2通过分子间氢键、C-H…π及π…π作用形成3D超分子结构。此外,讨论了H₂L¹,H₂L²及其相应的Ni（Ⅱ）和Zn（Ⅱ）配合物的荧光性质。配体H₂L¹和H₂L²呈现蓝色发射,最大发射波长λ_em分别为457和473 nm,而配合物1和2显示绿色发射,λ_em分别为543和538 nm。     

基于半刚性四面体四齿配体构筑的Zn(Ⅱ)/Cd(Ⅱ)配位聚合物及其性质

在水热的条件下,利用四(4-吡啶氧甲基)甲烷(L₁)或四(3-吡啶氧甲基)甲烷(L₂)、1,4-萘二甲酸(1,4-NDC)和d¹⁰金属离子发生自组装反应合成了2个化合物{[Cd₂(L₁)(1,4-NDC)₂]·2H₂O}_n(1)和{[Zn₂(L₂)(1,4-NDC)₂]·DMF·3H₂O)}_n(2)。单晶结构表明化合物1是通过L₁配体与一维链[Cd(1,4-NDC)]_n相连构建而成的三维骨架化合物,而化合物2是一对螺旋链与另外的一维链相互垂直交联而形成二维网络结构。更为重要的是,通过引入2种不同空间位阻的配体,研究了辅助配体对金属有机配位聚合物结构多样性的影响。另外,它们的荧光性质也做了相应的探讨。     

基于2-氨基-3-羟基-吡啶Schiff碱的双核Ni(Ⅱ)和Zn(Ⅱ)配合物:合成、超分子结构和光谱性质

合成了2个2-氨基-3-羟基-吡啶Schiff碱双核Ni（Ⅱ）和Zn（Ⅱ）配合物,[Ni（L¹）（DMF）]₂（1）（H₂L¹=4-羟基-3-（（3-羟基-吡啶-2-亚氨基））-苯并吡喃-2-酮）和[Zn（L²）（H₂O）]₂·2DMF（2）（H₂L²=2-（（3,5-二溴-2-羟基）-氨基）-吡啶-3-醇）,并通过元素分析、红外光谱、紫外-可见吸收光谱、荧光光谱及X射线单晶衍射分析等手段进行了表征。X射线单晶衍射分析结果表明：配合物1和2均具有双核结构,均由2个金属离子和2个配体单元以及2个配位的溶剂分子组成,不同的是配合物2含有2个溶剂分子。配合物1和2都是单斜晶系、P2₁/c空间群,且中心金属Ni（Ⅱ）和Zn（Ⅱ）离子的空间构型均为五配位的扭曲的四方锥。此外,配合物1和2通过分子间氢键、C-H…π及π…π作用形成3D超分子结构。此外,讨论了H₂L¹,H₂L²及其相应的Ni（Ⅱ）和Zn（Ⅱ）配合物的荧光性质。配体H₂L¹和H₂L²呈现蓝色发射,最大发射波长λ_em分别为457和473 nm,而配合物1和2显示绿色发射,λ_em分别为543和538 nm。     

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.     

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.     

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.     

Microwave-assisted copper-catalyzed stereoselective ring expansion of three-membered heterocycles with α-diazo-β-dicarbonyl compounds

Microwave-assisted copper-catalyzed ring expansions of three-membered heterocycles with α-diazo-β-dicarbonyl compounds were investigated. Thiiranes generated 3-acyl-5,6-dihydro-1,4-oxathiines in the presence of copper sulfate and trans-3-acyl-5,6-dihydro-1,4-oxathiines as stereospecific products for 1,2-disubstituted cis-thiiranes through an intramolecular S_N2 process. Oxiranes gave rise to 2-acyl-5,6-dihydro-1,4-dioxines under the catalysis of copper hexafluoroacetylacetonate and cis-3-acyl-5,6-dihydro-1,4-dioxines as stereospecific products for 1,2-disubstituted cis-oxiranes via an intimate ion-pair mechanism. The current method provides a direct and simple strategy in efficient preparation of 3-acyl-5,6-dihydro-1,4-oxathiines and 2-acyl-5,6-dihydro-1,4-dioxines, important agents in medicinal and agricultural chemistry, from readily available thiiranes and oxiranes, respectively.     

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.     

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%).