乙酰二茂铁缩肼基硫代甲酸苄酯的制备、晶体结构及光谱研究

近年来,在二茂铁的环戊二烯环上引入较活泼的酰基,从而使酰基二茂铁具有醛酮的一系列的典型反应生成具有-C=N-结构的新化合物逐渐成为人们研究的热点,二茂铁金属有机液晶材料的液晶性能和较高的应用价值也引起了人们广泛的研究兴趣[1].目前,所合成的这类新化合物主要是芳酸腙或芳香族Schiff碱类,而Schiff碱类化合物可与金属离子形成具有很强的生理活性和防止霉菌生长的活性配合物[2],可以作为抗菌、抗癌、抗肿瘤、抗结核等药物[3],同时还具有较高的催化,载氧和类SOD酶生物活性[4].     

蔬菜、水果中4种抗凝血灭鼠剂残留的高效液相色谱-串联质谱法测定

建立了蔬菜及水果中溴鼠灵、溴敌隆、敌鼠、杀鼠酮灭鼠剂同时检测的高效液相色谱-质谱/质谱(HPLC-MS/MS)分析方法,前处理采用乙腈提取、碱性氧化铝小柱净化.结果表明,4种灭鼠剂线性范围为2.0 ～50 μg/L,r均大于0.997 5;溴鼠灵和溴敌隆的检出限可达0.5 μg/kg,回收率分别为77% ～96%,69% ～113%;敌鼠和杀鼠酮的检出限为1.0 μg/kg,回收率分别为72% ～94%,71% ～90%;RSDs均小于10%,可以满足目前国际限量要求.     

3,4-二硝基呋咱的合成

以乙二醛为起始原料,常压法制备3,4-二氨基呋咱(DAF),收率56.4%,纯度98.4%.采用"一步法"氧化工艺,以50%H2O2为氧化剂,H2SO4起始浓度56.9%,于35℃反应3.5 h,由DAF合成了3,4-二硝基呋咱(DNF),收率62.5%,纯度99.8%.DNF的结构经13C NMR,IR,MS和元素分析表征.讨论了DAF氧化成DNF的反应历程.     

显色剂2-(5-羧基-1,3,4-三氮唑偶氮)-5-二乙氨基苯甲酸与钯(Ⅱ)的显色反应研究

研究了显色剂2-(5-羧基-1,3,4-三氮唑偶氮)-5-二乙氨基苯甲酸(CTZDBA)与钯(Ⅱ)的显色反应。结果表明,Pd(Ⅱ)与CTZDBA生成稳定的1∶2的紫红色配合物,其最大吸收波长为548 nm,配合物的表观摩尔吸光系数为9.32×104L.mol-1.cm-1,Pd(Ⅱ)质量浓度在0.08~0.8 mg/L范围内符合比耳定律。该方法可不经分离直接测定钯碳催化剂和钯纳米碳催化剂中的微量钯,测定结果与原子吸收法(AAS)基本相符。     

Asymmetric Thermally Activated Delayed Fluorescence Materials Rendering High-performance OLEDs Through both Thermal Evaporation and Solution-processing

Exploring high-efficiency thermally activated delayed fluorescence(TADF) materials is of great importance regarding to organic light-emitting diode(OLED). Herein, we present a design strategy for developing asymmetric TADF materials based on a diphenyl sulfone-phenoxazine structure, resulting in efficient TADF emitters(CzPXZ and t-CzPXZ) with aggregation-induced emission properties, while t-CzPXZ is modified with tert-butyl groups. The two compounds exhibit high solid-state luminescence, efficient TADF, and significantly impressive device performances by both thermal evaporation and solution processing. For an instance, CzPXZ and t-CzPXZ enable the thermally-evaporated OLEDs with high external quantum efficiencies(EQEs) of over 20%. Meanwhile, t-CzPXZ allows the solution-processed device with a high EQE of 16.3% with low-efficiency roll-off, attributing to the enhanced molecular solubility and suppressed excitons quenching through tert-butyl modification on t-CzPXZ. The results reveal that the proposed asymmetric structure is a promising approach for developing high-efficiency TADF materials and OLEDs.     

流动注射化学发光法测定盐酸米诺环素

在碱性条件下,K3[Fe(CN)6]氧化鲁米诺产生化学发光,盐酸米诺环素对该体系化学发光反应具有显著的抑制作用,据此建立了快速测定盐酸米诺环素的流动注射化学发光新方法。在优化的实验条件下,化学发光抑制强度与盐酸米诺环素的质量浓度在8.0~400 ng/m L范围内呈良好的线性关系,检出限为7.4 ng/m L。对200 ng/m L盐酸米诺环素连续平行测定11次,相对标准偏差为1.8%。方法可用于盐酸米诺环素片剂的测定。     

Pyridine-H_5PMo_(10)V_2O_(40) hybrid catalysts for liquid-phase hydroxylation of benzene to phenol with molecular oxygen

Pyridine(Py)-modified Keggin-type vanadium-substituted heteropoly acids(PynPMo10V2O40,n=1 to 5) were prepared by a precipitation method as organic/inorganic hybrid catalysts for direct hydroxylation of benzene to phenol in a pressured batch reactor and their structures were detected by FT-IR.Among various catalysts,Py3PMo10V2O40 exhibits the highest catalytic activity(yield of phenol,11.5%),without observing the formation of catechol,hydroquinone and benzoquinone in the reaction with 80 vol% aqueous acetic ...     

超高效液相色谱-质谱法测定环氧树脂粘结剂中双酚A

提出了环氧树脂粘结剂中双酚A的超高效液相色谱-质谱测定方法。样品用乙醇超声提取后,离心分离,取上清液过0.22μm有机滤膜,滤液经ZORBAX SB-C18色谱柱分离,用不同比例的水和乙腈的混合溶液作为流动相梯度淋洗,采用电喷雾负离子源,多反应监测模式。双酚A的质量浓度在2～1 000μg.L-1范围内与其峰面积呈线性关系,测定下限(10S/N)为0.5mg.kg-1。以空白环氧树脂粘结剂为基体,进行加标回收试验,测得回收率在89.3%～93.2%之间,测定值的相对标准偏差(n=6)在1.8%～3.3%之间。     

A computational investigation of boron-doped chromium and chromium clusters by density functional theory

The geometries,stabilities and electronic properties of Crn and CrnB(n=2-9) clusters have been systematically investigated by density functional theory.The results suggest that the lowest energy structures for CrnB clusters can be obtained by substituting one Cr atom in Crn+1 clusters with B atom.The geometries of CrnB clusters are similar to that of Crn+1 clusters except for local structural distortion.The second-order difference and fragmentation energy show Cr4,Cr6,Cr8,Cr3B,Cr5B and Cr8B cluster are the ...