Rapid cooling and microwave heating substantially speed up temperature cycling-enhanced deracemization, while limiting the concomitant side reactions. During fast cooling, secondary nucleation is shown to enable deracemization.
Artificial intelligence and specifically machine learning applications are nowadays used in a variety of scientific applications and cutting-edge technologies, where they have a transformative impact. Such an assembly of statistical and linear algebra methods making use of large data sets is becoming more and more integrated into chemistry and crystallization research workflows. This review aims to present, for the first time, a holistic overview of machine learning and cheminformatics applications as a novel, powerful means to accelerate the discovery of new crystal structures, predict key properties of organic crystalline materials, simulate, understand, and control the dynamics of complex crystallization process systems, as well as contribute to high throughput automation of chemical process development involving crystalline materials. We critically review the advances in these new, rapidly emerging research areas, raising awareness in issues such as the bridging of machine learning models with first-principles mechanistic models, data set size, structure, and quality, as well as the selection of appropriate descriptors. At the same time, we propose future research at the interface of applied mathematics, chemistry, and crystallography. Overall, this review aims to increase the adoption of such methods and tools by chemists and scientists across industry and academia.
Sustainable and decentralized manufacturing of hydrogen peroxide (H 2 O 2 ) has been extensively sought to replace the energy-and waste-intensive anthraquinone process. We introduce a helical biphasic microreactor in a coaxial dielectric barrier discharge (DBD) configuration as a modular, adaptable, and scalable intensified unit for H 2 O 2 production. Geometric and operating parameters such as electrode length, applied voltage, and gas and liquid flow rates can be tuned to regulate the residence time, delivered power, and gas−liquid interfacial area. In turn, these affect the key output parameters, i.e., H 2 O 2 concentration, production rate, and energy yield. We found a direct correlation between the H 2 O 2 production rate and the product of the interfacial area and residence time in the plasma region. We investigated the H 2 O 2 formation pathways using DMSO as an •OH radical scavenger and found that H 2 O 2 forms by the dissolution of gaseous H 2 O 2 at low interfacial areas and is enhanced probably due to the interfacial recombination of •OH radicals at a large gas−liquid interfacial area. The reactor temperature can also be externally controlled to intensify the production rate and energy yield of H 2 O 2 . Concentrations of up to 33 mM can be attained with a small footprint reactor that features a maximum energy yield of 4 g kWh −1 . The plasma microreactor could epitomize a powerful process intensification tool for sustainable and distributed chemical manufacturing.
Herein, the pivotal role of secondaryn ucleation in ac rystallization-enhanced deracemization process is reported. During this process, complete and rapid deracemization of chiral conglomerate crystalso fa ni soindolinone is attained through fast microwave-assistedt emperature cycling. Ap arametric study of the main factorst hat affect the occurrence of secondary nucleation in this process, namely agitation rate, suspension density,a nd solutes upersaturation, confirmst hat an enhanced stereoselective secondary nucleation rate maximizest he deracemizationr ate. Analysis of the systemd uring as ingle temperature cycle showed that, although stereoselective particlep roduction during the crystallization stage leadstoenantiomeric enrichment, undesired kinetic dissolution of smaller particleso ft he preferred enantiomero ccurs during the dissolution step. Therefore, secondary nucleationi sc rucial for the enhancemento fd eracemization through temperature cycles and as such should be considered in further design and optimization of this process, as well as in other temperature cyclingp rocesses commonly applied in particle engineering.
A novel continuous flow reactive crystallization process for the in situ on-demand access of single enantiomer crystals is reported and exemplified for a chiral pharmaceutical intermediate that crystallizes as a racemic conglomerate.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.