Nonaqueous capillary electrophoresis and quantum chemical calculations applied to investigation of acid‐base and electromigration properties of azahelicenes

2021 ◽  
Author(s):  
Veronika Šolínová ◽  
Sille Štěpánová ◽  
Andrej Jančařík ◽  
Jiří Klívar ◽  
Michal Šámal ◽  
...  
2014 ◽  
Vol 16 (26) ◽  
pp. 13047-13051 ◽  
Author(s):  
Gül Bekçioğlu ◽  
Christoph Allolio ◽  
Maria Ekimova ◽  
Erik T. J. Nibbering ◽  
Daniel Sebastiani

We investigate the acid–base proton exchange reaction in a microsolvated bifunctional chromophore by means of quantum chemical calculations.


2006 ◽  
Vol 27 (2) ◽  
pp. 423-432 ◽  
Author(s):  
Rita Carabias-Martínez ◽  
Encarnación Rodríguez-Gonzalo ◽  
Jesús Hernández-Méndez ◽  
Edith Miranda Cruz ◽  
Javier Domínguez-Álvarez

2020 ◽  
Author(s):  
Tsuyoshi Mita ◽  
Yu Harabuchi ◽  
Satoshi Maeda

The systematic exploration of synthetic pathways to afford a desired product through quantum chemical calculations remains a considerable challenge. In 2013, Maeda et al. introduced ‘quantum chemistry aided retrosynthetic analysis’ (QCaRA), which uses quantum chemical calculations to search systematically for decomposition paths of the target product and propose a synthesis method. However, until now, no new reactions suggested by QCaRA have been reported to lead to experimental discoveries. Using a difluoroglycine derivative as a target, this study investigated the ability of QCaRA to suggest various synthetic paths to the target without relying on previous data or the knowledge and experience of chemists. Furthermore, experimental verification of the seemingly most promising path led to the discovery of a synthesis method for the difluoroglycine derivative. The extent of the hands-on expertise of chemists required during the verification process was also evaluated. These insights are expected to advance the applicability of QCaRA to the discovery of viable experimental synthetic routes.


2020 ◽  
Author(s):  
Tsuyoshi Mita ◽  
Yu Harabuchi ◽  
Satoshi Maeda

The systematic exploration of synthetic pathways to afford a desired product through quantum chemical calculations remains a considerable challenge. In 2013, Maeda et al. introduced ‘quantum chemistry aided retrosynthetic analysis’ (QCaRA), which uses quantum chemical calculations to search systematically for decomposition paths of the target product and propose a synthesis method. However, until now, no new reactions suggested by QCaRA have been reported to lead to experimental discoveries. Using a difluoroglycine derivative as a target, this study investigated the ability of QCaRA to suggest various synthetic paths to the target without relying on previous data or the knowledge and experience of chemists. Furthermore, experimental verification of the seemingly most promising path led to the discovery of a synthesis method for the difluoroglycine derivative. The extent of the hands-on expertise of chemists required during the verification process was also evaluated. These insights are expected to advance the applicability of QCaRA to the discovery of viable experimental synthetic routes.


2019 ◽  
Author(s):  
Przemyslaw Rzepka ◽  
Zoltán Bacsik ◽  
Andrew J. Pell ◽  
Niklas Hedin ◽  
Aleksander Jaworski

Formation of CO<sub>3</sub><sup>2-</sup> and HCO<sub>3</sub><sup>-</sup> species without participation of the framework oxygen atoms upon chemisorption of CO<sub>2</sub> in zeolite |Na<sub>12</sub>|-A is revealed. The transfer of O and H atoms is very likely to have proceeded via the involvement of residual H<sub>2</sub>O or acid groups. A combined study by solid-state <sup>13</sup>C MAS NMR, quantum chemical calculations, and <i>in situ</i> IR spectroscopy showed that the chemisorption mainly occurred by the formation of HCO<sub>3</sub><sup>-</sup>. However, at a low surface coverage of physisorbed and acidic CO<sub>2</sub>, a significant fraction of the HCO<sub>3</sub><sup>-</sup> was deprotonated and transformed into CO<sub>3</sub><sup>2-</sup>. We expect that similar chemisorption of CO<sub>2</sub> would occur for low-silica zeolites and other basic silicates of interest for the capture of CO<sub>2</sub> from gas mixtures.


Author(s):  
Lucy van Dijk ◽  
Ruchuta Ardkhean ◽  
Mireia Sidera ◽  
Sedef Karabiyikoglu ◽  
Özlem Sari ◽  
...  

A mechanism for Rh(I)-catalyzed asymmetric Suzuki-Miyaura coupling with racemic allyl halides is proposed based on a combination of experimental studies and quantum chemical calculations. <br>


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