数十年来,碳酸亚乙酯(EC)已用作常规电解质中的固体电解质中间相(SEI)形成剂。但是,其低的阳极稳定性会导致在高压操作下循环期间严重的容量衰减。因此,寻找具有高阳极稳定性和形成用于高压锂离子电池的鲁棒SEI的能力的最重要的电解质。在这项研究中,已设计,合成和评估了一系列包含各种氟化环状碳酸酯作为SEI前体的电解质。线性扫描伏安法研究表明,氟化环状碳酸酯通常比EC具有更高的阳极稳定性。基于LiNi 0.5 Co 0.2 Mn 0.3 O 2的循环性能(NMC532)/石墨全电池,含DFEC / FEMC(1.0 M LiPF 6)的电解质抑制了阴极上的氧化副反应,并在阳极上形成了剧烈的SEI。利用新型电解质的高压NMC532 /石墨电池在室温和高温下均具有出色的循环耐久性。SEM,EDAX和XRD进一步揭示了基于DFEC的电解质的优越性能。循环后,使用DFEC基电解质的全电池阳极和阴极都保
Catalytic, Kinetic, and Mechanistic Insights into the Fixation of CO
<sub>2</sub>
with Epoxides Catalyzed by Phenol‐Functionalized Phosphonium Salts
作者:Yuya Hu、Zhihong Wei、Anna Frey、Christoph Kubis、Chang‐Yue Ren、Anke Spannenberg、Haijun Jiao、Thomas Werner
DOI:10.1002/cssc.202002267
日期:2021.1.7
A series of hydroxy‐functionalized phosphonium salts were studied as bifunctional catalysts for the conversion of CO2 with epoxides under mild and solvent‐free conditions. The reaction in the presence of a phenol‐based phosphonium iodide proceeded via a first order rection kinetic with respect to the substrate. Notably, in contrast to the aliphatic analogue, the phenol‐based catalyst showed no product
研究了一系列羟基官能化鏻盐作为双功能催化剂,用于在温和无溶剂条件下将CO 2与环氧化物转化。在苯酚基碘化鏻存在下,反应通过相对于底物的一级反应动力学进行。值得注意的是,与脂肪族类似物相比,苯酚基催化剂没有表现出产物抑制。研究了反应速率的温度依赖性,并根据阿伦尼乌斯图确定了模型反应的活化能(E a =39.6 kJ mol -1)。还评估了底物范围。在优化的反应条件下,20个末端环氧化物在室温下转化为相应的环状碳酸酯,分离收率高达99%。该反应易于扩展,可在高达 50 g 底物的规模上进行。此外,该方法还应用于以环氧氯丙烷和苯基哌嗪为原料合成镇咳药氟哌嗪。此外,还进行了 DFT 计算,以合理化苯酚基碘化鏻催化剂的机理和高效率。计算证实了环氧化物通过碘化物盐的氢键活化,从而促进了开环步骤。值得注意的是,关于该步骤的有效吉布斯能垒对于溴化物是97 kJ mol -1 ,对于碘化物盐是72 kJ mol
An in situ formed Ca<sup>2+</sup>–crown ether complex and its use in CO<sub>2</sub>-fixation reactions with terminal and internal epoxides
作者:J. Steinbauer、A. Spannenberg、T. Werner
DOI:10.1039/c7gc01114h
日期:——
Calcium punched beyond its weight: An in situ formed Ca2+–crown ether complex showed unprecedented efficiency in cyclic carbonate synthesis.
钙超出了其重量范围:一种原位形成的Ca2+–冠醚复合物在环状碳酸酯合成中表现出前所未有的效率。
Aluminum complexes with new non-symmetric ferrocenyl amidine ligands and their application in CO<sub>2</sub> transformation into cyclic carbonates
作者:Yersica Rios Yepes、Javier Martínez、Hiram Rangel Sánchez、Celso Quintero、M. Carmen Ortega-Alfaro、José G. López-Cortés、Constantin G. Daniliuc、Antonio Antiñolo、Alberto Ramos、René S. Rojas
DOI:10.1039/c9dt03808f
日期:——
A set of alkyl aluminum complexes supported by non-symmetric ferrocenyl amidine ligands were used as catalysts for the preparation of cycliccarbonatesfromepoxides and carbondioxide using Bu4NI as a co-catalyst. A modified method for the synthesis of aminoferrocene allowed us to obtain this precursor in quantitative yield. Treatment of aminoferrocene with the corresponding acetimidoyl chloride afforded
Aromatic guanidines as highly active binary catalytic systems for the fixation of CO<sub>2</sub> into cyclic carbonates under mild conditions
作者:Ángela Mesías-Salazar、Javier Martínez、René S. Rojas、Fernando Carrillo-Hermosilla、Alberto Ramos、Rafael Fernández-Galán、Antonio Antiñolo
DOI:10.1039/c9cy00667b
日期:——
We have synthesised a set of aromatic mono- and bis(guanidines) which are highly effective binary catalyticsystems (guanidine/cocatalyst) for the formation of cyclic carbonates. The presence of multiple N–H bonds causes a modification in the traditional mechanism proposed for the synthesis of cyclic carbonates catalysed by guanidines through the formation of hydrogen bonds between the oxygen atom
Toward a Neutral Single-Component Amidinate Iodide Aluminum Catalyst for the CO<sub>2</sub> Fixation into Cyclic Carbonates
作者:Sebastián Saltarini、Nery Villegas-Escobar、Javier Martínez、Constantin G. Daniliuc、Ricardo A. Matute、Lutz H. Gade、René S. Rojas
DOI:10.1021/acs.inorgchem.0c03290
日期:2021.1.18
A new iodide aluminum complex (AlI(κ4-naphbam)}, 3) supported by a tetradentate amidinate ligand derived from a naphthalene-1,8-bisamidine precursor (naphbamH, 1) was obtained in quantitative yield via reaction of the corresponding methyl aluminum complex (AlMe(κ4-naphbam)}, 2) with 1 equiv of I2 in CH2Cl2 at room temperature. Complexes2 and 3 were tested and found to be active as catalysts for
一种新的碘化铝络合物(ALI(κ 4 -naphbam)},3)由四齿配体脒从萘-1,8-双脒前体(naphbamH,衍生支持1)通过相应的反应以定量产率得到甲基铝络合物(阿尔梅(κ 4 -naphbam)},2)与1个当量的我2在CH 2氯2在室温下。测试了配合物2和3,发现它们在80°C和1 bar CO 2的条件下可作为由环氧化物形成环状碳酸酯的催化剂具有活性压力。以1.5摩尔%的烷基络合物2和1.5摩尔%的四丁基碘化铵(TBAI)作为助催化剂进行第一系列的实验。随后,用1.5mol%的碘化物络合物3作为单组分催化剂进行反应。化合物3是非两性离子卤化物单组分铝催化剂生产环状碳酸酯的第一个实例。使用密度泛函理论通过量子化学计算(QCC)表征了具有所有最小和过渡态特征的完整催化循环。反应机理上的QCC支持基于催化剂中碘与1当量环氧化物的交换的反应途径,随后I –生成环氧化物的环开口的