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排序方式: 共有305条查询结果,搜索用时 15 毫秒
1.
Zhiyu Wang Dr. Xiaoming Wang Zhongwei Chen Dr. Yang Liu Huilin Xie Jie Xue Prof. Lingling Mao Prof. Yanfa Yan Prof. Haipeng Lu 《Angewandte Chemie (International ed. in English)》2023,62(17):e202215206
Introducing chirality into the metal-halide hybrids has enabled many emerging properties including chiroptical activity, spin-dependent transport, and ferroelectricity. However, most of the chiral metal-halide hybrids to date are non-emissive, and the underlying mechanism remains elusive. Here, we show a new strategy to turn on the circularly polarized luminescence (CPL) in chiral metal-halide hybrids. We demonstrate that alloying Sb3+ into chiral indium-chloride hybrids dramatically increases the photoluminescence quantum yield in two new series of chiral indium-antimony chlorides. These materials exhibit strong CPL signals with tunable energy and a high dissymmetry factor up to 1.5×10−2. Mechanistic studies reveal that the emission originates from the self-trapped excitons centered in 5s2 Sb3+. Moreover, near-ultraviolet pumped white light is demonstrated with a polarization up to 6.0 %. Our work demonstrates new strategies towards highly luminescent chiral metal-halide hybrids. 相似文献
2.
Sylvain Sudan Damien W. Chen Cesare Berton Farzaneh Fadaei-Tirani Kay Severin 《Angewandte Chemie (International ed. in English)》2023,62(9):e202218072
A water-soluble coordination cage was obtained by reaction of Pd(NO3)2 with a 1,3-di(pyridin-3-yl)benzene ligand featuring a short PEG chain. The cavity of the metal-organic cage contains one nitrate anion, which is readily replaced by chloride. The apparent association constant for chloride binding in buffered aqueous solution is Ka=1.8(±0.1)×105 M−1. This value is significantly higher than what has been reported for other macrocyclic chloride receptors. The heavier halides Br− and I− compete with binding or self-assembly, but the receptor displays very good selectivity over common anions such as phosphate, acetate, carbonate, and sulfate. A further increase of the chloride binding affinity by a factor of 3 was achieved using a fluorinated dipyridyl ligand. 相似文献
3.
Derk Balthazar de Graaf Yawar AbbasJohan Gerrit Bomer Wouter OlthuisAlbert van den Berg 《Analytica chimica acta》2015
Chloride is a crucial anion for various analytical applications from biological to environmental applications. In order to measure the chloride ion concentration, a measurement system is needed which can detect this concentration for prolonged times reliably. Chronopotentiometry is a technique which does not need a long term stable reference electrode and is therefore very suitable for prolonged ion concentration measurements. As the used electrode might be fouled by reaction products, this work focuses on a chronopotentiometric approach with a separated sensing electrode (sensor) and actuating electrode (actuator). Both actuation and sensor electrode are made of Ag/AgCl. A constant current is applied to the actuator and will start the reaction between Ag and Clˉ, while the resulting Clˉ ion concentration change is observed through the sensor, which is placed close to the actuator. The time it takes to locally deplete the Clˉ ions is called transition time. Experiments were performed to verify the feasibility of this approach. The performed experiments show that the sensor detects the local concentration changes resulting from the current applied to the actuator. A linear relation between the Clˉ ion concentration and the square root of the transition time was observed, just as was predicted by theory. The calibration curves for different chips showed that both a larger sensor and a larger distance between sensor and actuator resulted in a larger time delay between the transition time detected at the actuator and the sensor. 相似文献
4.
The N2 laser excited fluorescence spectrum and the intensity of fluorescence of oxalyl chloride C2O2Cl2) condensed at 77°K either alone, or, diluted with a non-hydrocarbon or a hydrocarbon with dilution ratios ranging from 10 to 100 were studied. A slow condensation of the hydrocarbon matrix diluted sample showed a considerable reduction in the fluorescence intensity as compared to a fast condensation of the same sample. 相似文献
5.
《Phosphorus, sulfur, and silicon and the related elements》2013,188(10):2107-2110
Alcohols were oxidized to their corresponding carbonyl compounds with KBrO 3 in the presence of silica chloride and wet SiO 2 , in solution and under solvent free conditions. 相似文献
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7.
应用自动电位滴定法,在总离子强度缓冲溶液存在的情况下,在pH 5的微酸性水溶液中,用0.05mol·L~(-1)硝酸银标准溶液作为滴定剂,测定了脱硫系统样品中氯化物含量。试样用水浸取溶出氯化物,共存亚硫酸盐的干扰采用在近中性条件下加入过氧化氢煮沸至无小气泡产生予以消除,对试样的预处理方法以及各项影响测定的参数等做了试验并予以优化。方法用于测定脱硫废水、脱硫浆液和脱硫石膏样品中氯化物,加标回收率在95.7%~102.0%之间,相对标准偏差(n=5)在1.2%~5.9%之间。 相似文献
8.
采用离子色谱法测定选矿废水中微量F-、Cl-、NO3-、SO42-的含量。以SH-AC-1型阴离子分离柱为离子交换柱,以2.5 mmol.L-1碳酸钠-3.5 mmol.L-1碳酸氢钠溶液为淋洗液,采用抑制电导器检测。F-、Cl-、NO3-、SO24-4种阴离子分别在0.01~4.0,0.01~15.0,0.01~15.0,0.01~30.0 mg.L-1范围内呈线性关系,检出限(3S/N)分别为6.13,3.89,5.86,8.49μg.L-1。方法用于选矿废水试样中4种阴离子的测定,加标回收率分别为97.5%,104.0%,102.0%,98.3%,相对标准偏差均小于4.0%。 相似文献
9.
提出了煤粉直接压片制样-X射线荧光光谱法测定原煤中氯量。将粒径小于74μm的原煤粉末经90℃烘干后置于聚乙烯模具中,以4.16 MPa压力制成直径为35 mm的样片,制成的样品保存于干燥器中应尽快进行测定。选用煤标准物质制作氯的测定范围为0.01%~0.11%(质量分数)之间的标准曲线,并建立了集校准曲线、基体校正及谱线重叠校正为一体的回归方程作为方法的定量基础。求得方法的检出限为15μg·g~(-1)。用同一标准物质(ω_(Cl)0.057%)重复测定12次,测得其相对标准偏差为1.85%。用所提出的方法测定了2个煤标准物质,所得结果与认定值一致。 相似文献
10.
800合金作为核电站蒸汽发生器的一种关键材料,服役环境下其表面钝化膜的特性一直是人们研究的热点.本文用Mott-Schottky方法研究了800合金在不同硫酸根离子和氯离子浓度比的溶液中钝化膜的半导体特性,并结合电化学阻抗谱(EIS)、扫描电镜(SEM)、扫描电化学显微镜(SECM)研究了钝化膜的耐蚀性和表面活性.Mott-Schottky结果表明,800合金表面钝化膜的半导体特性与溶液中硫酸根、氯离子的浓度比有关,随硫酸根与氯离子浓度比的降低,半导体特性发生转变.当硫酸根与氯离子的浓度比较高时,钝化膜为p型半导体;而当硫酸根与氯离子的浓度比较低时,钝化膜为n型半导体.EIS、SECM、SEM结果表明,随浓度比的降低钝化膜由过钝化溶解转为明显的点蚀特征,钝化膜表面活性增加.钝化膜特性的改变与其半导体类型的转变密切相关,而半导体特性的转变由氯离子、硫酸根离子在800合金钝化膜表面的竞争吸附所致,其在表面的竞争吸附直接影响钝化膜表面发生的化学反应,改变电极/溶液界面电势差,使钝化膜中的空位类型改变,最终决定半导体类型. 相似文献