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Kondo, Tomomi; Sasaki, Takehiko*; Shiga, Motoyuki
Journal of Computational Chemistry, 42(25), p.1783 - 1791, 2021/09
Times Cited Count：1 Percentile：6.77(Chemistry, Multidisciplinary)Sugar alcohol dehydration in hot water is an important reaction that allows for environmentally friendly biomass conversion without the use of organic solvents. Here, we report a free-energy analysis by metadynamics (MTD) simulations based on ab initio and semiempirical electronic structure theory to understand the mechanism of dehydration reactions of sorbitol (SBT) in hot acidic water. It was found that the reaction proceeds via an S
2 mechanism, whereby the free energy of protonation of the hydroxyl group created as an intermediate is affected by the acidic species. The free energy barriers of the reaction pathways leading to five-membered ether products are lower than those leading to six-membered ether products.
Kondo, Tomomi; Sasaki, Takehiko*; Ruiz-Barragan, S.*; Ribas-Ari
o, J.*; Shiga, Motoyuki; Ruiz-Barragan, S.*
Journal of Computational Chemistry, 42(3), p.156 - 165, 2021/01
Times Cited Count：4 Percentile：21.18(Chemistry, Multidisciplinary)We propose a canonical sampling method to refine metadynamics simulations a posteriori. This approach could be useful particularly when two or more free energy barriers are to be compared among chemical reactions in different or competing conditions. The method was then applied to study the acid dependence of polyalcohol dehydration reactions in high-temperature aqueous solutions. It was found that the reaction proceeds consistently via an S2 mechanism, whereby the free energy of protonation of the hydroxyl group created as an intermediate is affected significantly by the acidic species.
Takeda, Nobukazu; Kakudate, Satoshi; Shibanuma, Kiyoshi; Tsuji, Koichi*; Kubo, Tomomi*; Maruyama, Kensuke*; Kondo, Mitsunori*
no journal, ,
no abstracts in English
Koizumi, Satoshi; Tomita, Yoko*; Zhao, Y.; Iwase, Hiroki*; Yamaguchi, Daisuke; Kondo, Tetsuo*; Hashimoto, Takeji; Masui, Tomomi
no journal, ,
no abstracts in English
