石墨烯/CdTe量子点复合物的合成及在克伦特罗检测方面的应用

成功地合成了石墨烯/CdTe量子点复合物,并采用透射电镜、紫外吸收光谱、荧光发射光谱、荧光衰减曲线和X射线光电子能谱对产物进行了表征。透射电镜结果显示CdTe量子点被修饰于石墨烯的表面;X射线光电子能谱结果表示石墨烯在合成过程中被还原,还表明在所合材料的表面具有羧基和羟基;荧光发射光谱和荧光衰减曲线的结果显示将CdTe量子点修饰于石墨烯表面显著提高了CdTe量子点的荧光性能。此外,基于克伦特罗和石墨烯/CdTe量子点复合物之间形成的氢键,所合成材料可用于定量分析克伦特罗。克伦特罗对石墨烯/CdTe量子点复合物具有显著的猝灭作用,荧光强度的降低（F₀/F）与克伦特罗之间存在良好的线性关系,线性范围为7.22~108.30 μmol·L^-1,检出限为4 μmol·L^-1。     

石墨烯/CdTe量子点复合物的合成及在克伦特罗检测方面的应用（英文）

成功地合成了石墨烯/CdTe量子点复合物,并采用透射电镜、紫外吸收光谱、荧光发射光谱、荧光衰减曲线和X射线光电子能谱对产物进行了表征。透射电镜结果显示CdTe量子点被修饰于石墨烯的表面;X射线光电子能谱结果表示石墨烯在合成过程中被还原,还表明在所合材料的表面具有羧基和羟基;荧光发射光谱和荧光衰减曲线的结果显示将CdTe量子点修饰于石墨烯表面显著提高了CdTe量子点的荧光性能。此外,基于克伦特罗和石墨烯/CdTe量子点复合物之间形成的氢键,所合成材料可用于定量分析克伦特罗。克伦特罗对石墨烯/CdTe量子点复合物具有显著的猝灭作用,荧光强度的降低(F0/F)与克伦特罗之间存在良好的线性关系,线性范围为7.22~108.30μmol·L-1,检出限为4μmol·L-1。     

基于多金属氧酸盐和多壁碳纳米管的双酚A电化学传感器的构建与性质

选择含N配体（L=1,3-双（1-咪唑）丙烷）与磷钼酸（H₃PMo₁₂O₄₀）水热合成了一个新的无机-有机杂化化合物（H₂L）₂（HL）₂L （PMo₁₂O₄₀）₂·2H₂O （PMo₁₂）。通过红外、热重、X射线光电子能谱、X射线粉末衍射和单晶衍射等对该化合物进行了表征。X射线单晶衍射表明该化合物为3D结构。将该化合物和多壁碳纳米管修饰在玻碳电极上构造了一种双酚A电化学传感器并对其传感性能进行研究。研究表明,在1~20 μmol·L^-1范围内,检出限为0.5 μmol·L^-1（S/N=3）,并且该传感器具有良好的抗干扰和稳定性。     

锰掺杂硒硫化镉光阳极的制备与光电性能

将适量Se加入到Na2S甲醇水溶液中反应生成Na₂SSe₂阴离子前驱体, 以Cd(NO₃)2、Mn(CH3COO)2为阳离子前驱体, 通过连续离子层吸附反应(SILAR)分别制备出CdSSe₂/TiO₂或 MN²⁺掺杂的Mn-CdSSe₂/TiO₂量子点敏化光阳极。采用拉曼光谱、X射线光电子能谱和能量色散X射线能谱分析确定阴离子前驱体和量子点的价键结构和组成;通过紫外可见吸光光谱表征量子点的光吸收性能;利用J-V曲线和IPCE分别对CdS、CdSSe₂和Mn-CdSSe₂量子点敏化的TiO₂光阳极的光电性能进行了表征。实验结果表明, 采用 0.12 mol·L^-1 Se和0.5 mol·L^-1 Na2S制备的阴离子前驱体、0. 5 mol·L^-1 Cd²⁺和 0.3 mol·L^-1 MN²⁺阳离子前驱体, 通过SILAR法制备的Mn-CdSSe₂/TiO₂光阳极, 能量转换效率比CdSSe₂/TiO₂和CdS/TiO₂光阳极分别提高了90%和247%。     

Li4SrCa (SiO4)2:Eu3+红色荧光粉的合成及其发光性能

采用硅酸盐作为基质材料,通过高温固相法合成了Li₄SrCa（SiO₄）₂：Eu³⁺红色荧光粉。通过X射线粉末衍射、X射线光电子能谱、透射电镜和荧光光谱,对所得样品的物相、形貌及其发光性能进行了表征分析。结果表明,掺入Eu³⁺后,Li₄SrCa（SiO₄）₂的晶体结构并没有发生改变。在393 nm光激发下,荧光粉的荧光光谱中693 nm处发射峰强度最强。以693 nm作为监测波长,荧光激发峰分别为361 nm（⁷F₀→⁵D₄）、375 nm（⁷F₀→⁵G₃）、413 nm（⁷F₀→⁵D₃）、393 nm（⁷F₀→⁵L₆）和464 nm（⁷F₀→⁵D₂）,即样品对近紫外和蓝光有较好的吸收。利用发射光谱研究了Eu³⁺掺杂浓度（物质的量分数）对荧光粉发光强度的影响。当Eu³⁺的掺杂浓度x=0.10时,样品发射强度最强,发射红光,其色坐标为（0.637 5,0.353 7）。通过Dexter强度与浓度关系分析了浓度猝灭机制。     

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。     

Co3O4/ZnO修饰针灸针的制备及其在葡萄糖检测领域的应用

将Co₃O₄/ZnO针状纳米棒材料修饰到针灸针表面用于检测葡萄糖浓度的变化。首先采用水热法在针灸针表面得到 Co（CO₃）_0.5（OH）·0.11H₂O针状纳米棒前驱体,然后在500 ℃条件下退火3 h得到Co₃O₄针状纳米棒阵列。再采用浸渍法将预制备好的ZnO量子点修饰到Co₃O₄针状纳米棒表面,得到Co₃O₄/ZnO复合修饰的针灸针。研究发现此针灸针对葡萄糖具有较好的电流响应（2 264.27 μA·L·mmol^-1·cm^-2）、较快的响应速度（<4 s）及较低的检测极限（0.311 μmol·L^-1（S/N=3））。且该针灸针在用于检测人体模拟细胞液中葡萄糖浓度时,对抗坏血酸和尿素等表现出较强的抗干扰性。     

锰掺杂硒硫化镉光阳极的制备与光电性能

将适量Se加入到Na₂S甲醇水溶液中反应生成Na₂SSe₂阴离子前驱体, 以Cd(NO₃)₂、Mn(CH₃COO)₂为阳离子前驱体, 通过连续离子层吸附反应(SILAR)分别制备出CdSSe₂/TiO₂或 Mn²⁺掺杂的Mn-CdSSe₂/TiO₂量子点敏化光阳极。采用拉曼光谱、X射线光电子能谱和能量色散X射线能谱分析确定阴离子前驱体和量子点的价键结构和组成;通过紫外可见吸光光谱表征量子点的光吸收性能;利用J-V曲线和IPCE分别对CdS、CdSSe₂和Mn-CdSSe₂量子点敏化的TiO₂光阳极的光电性能进行了表征。实验结果表明, 采用 0.12 mol·L^-1 Se和0.5 mol·L^-1 Na₂S制备的阴离子前驱体、0.5 mol·L^-1 Cd²⁺和 0.3 mol·L^-1 Mn²⁺阳离子前驱体, 通过SILAR法制备的Mn-CdSSe₂/TiO₂光阳极, 能量转换效率比CdSSe₂/TiO₂和CdS/TiO₂光阳极分别提高了90%和247%。     

Co3O4/ZnO修饰针灸针的制备及其在葡萄糖检测领域的应用

将Co₃O₄/ZnO针状纳米棒材料修饰到针灸针表面用于检测葡萄糖浓度的变化。首先采用水热法在针灸针表面得到Co（CO₃）_0.5（OH）·0.11H₂O针状纳米棒前驱体,然后在500 ℃条件下退火3 h得到Co₃O₄针状纳米棒阵列。再采用浸渍法将预制备好的ZnO量子点修饰到Co₃O₄针状纳米棒表面,得到Co₃O₄/ZnO复合修饰的针灸针。研究发现此针灸针对葡萄糖具有较好的电流响应（2 264.27 μA·L·mmol^-1·cm^-2）、较快的响应速度（<4 s）及较低的检测极限（0.311 μmol·L^-1（S/N=3））。且该针灸针在用于检测人体模拟细胞液中葡萄糖浓度时,对抗坏血酸和尿素等表现出较强的抗干扰性。     

高浓度氮掺杂多孔石墨烯的可控制备及类酶催化性质

通过改进的Hummer法合成氧化石墨烯（GO）,然后以氨水为氮源,经过一步水热法温和地制备了具有丰富纳米孔的氮掺杂还原氧化石墨烯（N-RGO）筛网状片层。N-RGO显示出高效的类酶催化活性,可以催化氧化多种有机化合物发生显色反应,如3,3'',5,5''-四甲基联苯胺（TMB）、邻苯二胺（OPD）、2,2''-叠氮基-二（3-乙基苯并噻唑啉磺酸）（ABTS）等。利用透射电子显微镜（TEM）、Raman光谱和X射线光电子能谱（XPS）对其进行系统表征。通过平行试验证明N-RGO催化氧化TMB是氧气参与的高效4电子转移反应过程。催化性能测试表明N-RGO相对辣根过氧化物酶（HPR）表现出了更强的耐受性,在较宽范围内（温度25~85℃,pH值4~7,NaCl浓度0~100 mmol·L^-1）均具有类酶催化活性。通过Michaelis-Menten模型的拟合可知,当GO浓度为5 mg·mL^-1时合成的N-RGO表现出较低的米氏常数（K_m≈0.2 mmol·L^-1）和较高的反应速率（v_max≈0.07 μmol·L^-1）。     

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.     

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.     

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.     

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.