Chemistry-Methods

Abstract Liquid Cell Transmission Electron Microscopy (LCTEM) is a great progression in nanostructure imaging, allowing the observation of chemical reactions in real time. It is widely reported, that this technique can be successfully used for analyzing nanoparticles synthesis, diffusion, aggregation and degradation. This gives a completely new insight into nanotechnological research. Normally, samples in TEM must be observed in vacuum, showing only the results of a performed experiment, whereas in situ observations in liquid environment provide information about the dynamics of the processes. LCTEM can show, how orientation of the particles/aggregates, surface roughness or solution flow rate influence the examined reaction. Those data are highly valuable for creating kinetic models of the reactions. There are however still some obstacles in LCTEM. Imaging of nanostructures in liquid environment is problematic since the electron beam reportedly may affect the observed sample. The beam modifies the temperature and pH of the liquid sample, changing the process dynamics. Therefore, its influence needs to be considered during in situ TEM observations. Nevertheless, LCTEM remains one of the highest achievements in the field of nanostructures imaging. In this review, recent achievements and developments of the LCTEM technique are presented.

Tomasz Tarnawski

Magdalena Parlińska‐Wojtan

Chemistry - Methods

Opportunities and Obstacles in LCTEM Nanoimaging – a review

LCTEM纳米成像中的机遇与挑战——综述

Jan Kulenkampff

Christian Armbruster

Johanna Drolshagen

Celine Regnat

Tina Wienold

Luisa Spari

Jana Fix

Tabea Sterbak

Harald Scherer

Ingo Krossing

Cover Picture: Video Documented Upscaled Synthesis of Salts of the Parent Carbaborate Ion [CB11H12]−, its Undecafluorinated Form [CHB11F11]− and Useful Starting Materials for its Introduction (Chem. Methods 11/2024)

封面图片：母碳硼烷离子盐[CB11H12]−及其十一氟化形式[CHB11F11]−的放大合成视频记录及其实用起始材料的引入（《化学方法》2024年11月刊）

Abstract Introduce meso/macro‐pore to the crystal of SAPO‐34 is an efficient way to overcome its inherent diffusion resistance. Porogen, formation hierarchical structure by inhibiting the growth of the crystals, would increase the costs of SAPO‐34 and is usually not friendly to environment. In this work, an ingrowth route to synthesize hierarchical SAPO‐34 is developed by secondary silica addition via hydrothermal method. Hierarchical porous SAPO‐34 was synthesized without adding any pore‐generating agent. Secondary silica addition put off the Si and P transferring from the mother liquid to gel phase, leading to the chemical composition of surface first meeting to the crystallization conditions. Then the crystallization started from the surface to the inside of the amorphous particles. The hierarchical SAPO‐34 showed numerous meso/macro pore structure and weaker acid strength. So the hierarchical SAPO‐34 showed better catalytic activity than the conventional SAPO‐34 in MTO reaction.

Xuefeng Shen

Jiajia Ding

Yingchun Ye

Hongxing Liu

Zaiku Xie

Ingrown Leading to Hierarchical SAPO‐34 with High Catalytic Activity

高催化活性分级SAPO-34的嵌入生长

Abstract Effects of various A dditives, B ase, C atalyst, as well as s ubstrates on the mechanochemically‐induced Suzuki‐Miyaura reaction have been studied. In situ Raman monitoring of the solid‐state reactions gave a detailed view of the reaction course and allowed a direct comparison of the time‐resolved product formation. The acquired knowledge allows in‐depth understanding of the reaction, especially the action of the catalyst in presence of diverse chemicals, leading to the more efficient cross coupling reactions in the solid state.

Mario Pajić

Dajana Barišić

Darko Babić

Manda Ćurić

Marina Juribašić Kulcsár

From In Situ Monitoring to Better Understanding of the Suzuki‐Miyaura Cross Coupling in the Solid State

从原位监测到更好地理解固态下的铃木-宫浦交叉偶联反应

Abstract The incorporation of a labeled 13 C atom provides a plethora of opportunities in organic synthesis and catalysis. Structure of complicated compounds can be successfully confirmed using the precise location of a labeled carbon atom; a reaction mechanism can be supported by the presence or absence of a label in reaction products; metabolic pathways of biological compounds can be found out depending on labeled products; the concentration of analyzed labeled compounds can be significantly lower for recording and successful interpretation of NMR spectra, etc . This review aims to provide a researcher with common and promising strategies for the synthesis of labeled compounds so that a researcher can select an appropriate route to save valuable labeled material. All the labeling approaches were considered based on starting labeling source. Ideological aim of the review is to demonstrate the opportunities for label incorporation so that a researcher can find the improvements in his own topic using labeled compounds. Utilization of labeled compounds in catalysis and studying reaction mechanisms were also considered to demonstrate the capabilities of labeled compounds, which may be useful in specific tasks and applications. The potential of labeled compounds in bioactive compound metabolite analysis was demonstrated on selected examples.

Konstantin S. Rodygin

Alexander S. Bogachenkov

Yulia V. Gyrdymova

Anton N. Potorochenko

13C‐Labeling as a Method in Organic Synthesis, Catalysis and Biochemical Applications

13C标记在有机合成、催化及生物化学应用中的方法

Abstract Renewable chemicals from carbohydrate‐rich wastes, like furfural and 5‐hydroxymethylfurfural (HMF), are gaining prominence as alternatives to petroleum‐based resources. Assessing the suitability of biomass as feedstock for furfural and HMF production requires knowledge of its composition. This study focuses on developing and validating predictive models for individual sugar concentrations in hydrolysates using quantitative 1H NMR data. Utilizing partial least square (PLS) regression, the dataset includes 137 NMR spectra of multi‐component sugar standards (arabinose, fructose, galactose, glucose, mannose, maltose, sucrose, and xylose). The best‐performing model achieved an R 2 of 0.987–0.999 and RMSECV of 0.37–1.56 mM and is based on the non‐overlapping area of the NMR spectrum. Real‐world samples were used for validation, resulting in predicted sugar concentrations with a mean standard deviation of 0.5 mM. This high accuracy and streamlined analysis process make these models practical for quantifying large sample sets, showcasing the reliability and accessibility of extracting statistical information from H‐NMR data.

Kristoffer Mega Herdlevær

Kasper Strandengen

Camilla Løhre

Tanja Barth

Determination of Sugar Concentrations in Aqueous Solution Using Multivariate Predictions Based on 1H‐NMR Spectroscopy

基于1H-NMR光谱的多变量预测法测定水溶液中糖浓度的研究

Abstract Reactor automation is a transformative force for chemical processes, but the potential of reaction monitoring for machine‐assisted autonomous biocatalytic reaction optimization is still largely unexplored. To address this gap, we report on automated reactor optimization for biocatalytic flow‐through microreactors. For this purpose, the inline NMR analysis of an enzymatically catalyzed stereoselective reduction of a prochiral diketone was combined with a self‐developed open‐source analysis and control software. The algorithm is continuously fed with spectra from a benchtop NMR instrument acquired from a reaction solution from a microreactor filled with biocatalytically active materials and adjusts the flow rate of the pumps to achieve predetermined target concentrations of the product. We show that through this automated coupling of data analysis and process parameterization, for example, maximum conversion efficiency can be achieved for a given bioreactor. This work illustrates the potential of inline NMR reaction monitoring for biocatalytic processes and provides a starting point for innovation to develop automated processes for precision biocatalysis through integrated data analysis.

Felix Ott

Gudrun Gygli

Kersten S. Rabe

Christof M. Niemeyer

Towards Precision Biocatalysis ‐ Leveraging Inline NMR for Autonomous Experimentation in Flow Reactors

面向精准生物催化——利用在线核磁共振实现流动反应器中的自主实验

Abstract A time resolved in situ X‐ray powder diffraction study using synchrotron radiation allowed for describing the evolution of the zeolite FAU structure during the development of a zeolite‐templated carbon (ZTC) in its porous voids. During the ZTC formation the intensity decrease of most zeolite reflections and the simultaneous rise in intensity of the 222 reflection (of null intensity in the pristine zeolite) was observed. Full pattern profile fitting by Rietveld refinement allowed for achieving a detailed description of the underlying chemistry, with coincident pore filling with carbon atoms in specific positions and framework distortion. Monitoring the intensity profiles of the 222 reflection allowed assessment of the energetics of the ZTC formation. Our results contribute to a better understanding of the phenomena involved on the atomic scale in ZTC synthesis.

Thibaud Aumond

Martin Esteves

Cristian Mocuta

Isabelle Batonneau‐Gener

Julien Haines

Ricardo Faccio

Alexander Sachse

In situ X‐Ray Powder Diffraction Investigation on the Development of Zeolite‐Templated Carbons in FAU zeolite

原位X射线粉末衍射研究FAU沸石中沸石模板碳的形成

Abstract The solution state of macromolecules in concentrated solutions impacts fields ranging from cell biology, to colloid chemistry and engineering of protein pharmaceuticals. Dependent on the interplay between repulsive and weakly attractive forces, proteins may exhibit oligomerization, aggregation, crystallization, liquid‐liquid phase separation, or the formation of multiprotein complexes. The particle size‐distribution is a key characteristic, but difficult to determine when interparticle distances are on the order of their size and macromolecular motion is coupled through hydrodynamic interactions. Here we extend sedimentation velocity analytical ultracentrifugation to measure macromolecular size distributions under these conditions: We apply results from statistical fluid mechanics for the concentration‐dependence of hindered settling and diffusion, embedded in a mean‐field approximation that can resolve coupled sedimentation and diffusion processes of different sized species given experimental sedimentation data. This is combined with a description of transient optical aberrations from lensing in the refractive index gradients associated with sedimentation boundaries (Wiener skewing). We demonstrate this approach in the application to protein solutions with macromolecular volume fractions up to ≈10 %, for example, resolving monomers and dimers of albumin at 140 mg/ml. This enables size‐distribution analysis of proteins at concentrations of therapeutic antibody formations and close to physiological concentration in serum and cells.

Sumit K. Chaturvedi

Peter Schuck

Analysis of Macromolecular Size Distributions in Concentrated Solutions

浓溶液中大分子尺寸分布的分析

短名	Chemistry Methods
Journal Impact	5.95
国际分区	CHEMISTRY, MULTIDISCIPLINARY(Q1)

出版信息	出版商: John Wiley and Sons Inc，出版周期: ，期刊类型: journal，开源期刊: 否
基本数据	创刊年份: 2021，原创研究文献占比: ，自引率:， Gold OA占比:

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Opportunities and Obstacles in LCTEM Nanoimaging – a review

Cover Picture: Video Documented Upscaled Synthesis of Salts of the Parent Carbaborate Ion [CB₁₁H₁₂]⁻, its Undecafluorinated Form [CHB₁₁F₁₁]⁻ and Useful Starting Materials for its Introduction (Chem. Methods 11/2024)

Ingrown Leading to Hierarchical SAPO‐34 with High Catalytic Activity

From In Situ Monitoring to Better Understanding of the Suzuki‐Miyaura Cross Coupling in the Solid State

¹³C‐Labeling as a Method in Organic Synthesis, Catalysis and Biochemical Applications

Determination of Sugar Concentrations in Aqueous Solution Using Multivariate Predictions Based on 1H‐NMR Spectroscopy

Towards Precision Biocatalysis ‐ Leveraging Inline NMR for Autonomous Experimentation in Flow Reactors

In situ X‐Ray Powder Diffraction Investigation on the Development of Zeolite‐Templated Carbons in FAU zeolite

Analysis of Macromolecular Size Distributions in Concentrated Solutions

Ingrown Leading to Hierarchical SAPO‐34 with High Catalytic Activity