110640 20240124152521.0 doi 10.1038/s41598-021-88060-7 sideral 125756 ART-2021-125756 eng Bescós, A. Theoretical insight on the treatment of ß-hexachlorocyclohexane waste through alkaline dehydrochlorination 2021 Access copy available to the general public Unrestricted The occurrence of 4.8–7.2 million tons of hexachlorocyclohexane (HCH) isomers stocked in dumpsites around the world constitutes a huge environmental and economical challenge because of their toxicity and persistence. Alkaline treatment of an HCH mixture in a dehydrochlorination reaction is hampered by the low reactivity of the ß-HCH isomer (HCl elimination unavoidably occurring through syn H–C–C–Cl arrangements). More intriguingly, the preferential formation of 1, 2, 4-trichlorobenzene in the ß-HCH dehydrochlorination reaction (despite the larger thermodynamical stability of the 1, 3, 5-isomer) has remained unexplained up to now, though several kinetic studies had been reported. In this paper, we firstly show a detailed Density Functional study on all paths for the hydroxide anion-induced elimination of ß-HCH through a three-stage reaction mechanism (involving two types of reaction intermediates). We have now demonstrated that the first reaction intermediate can follow several alternative paths, the preferred route involving abstraction of the most acidic allylic hydrogen which leads to a second reaction intermediate yielding only 1, 2, 4-trichlorobenzene as the final reaction product. Our theoretical results allow explaining the available experimental data on the ß-HCH dehydrochlorination reaction (rate-determining step, regioselectivity, instability of some reaction intermediates). © 2021, The Author(s). info:eu-repo/grantAgreement/ES/DGA-ERDF/E37-20R info:eu-repo/grantAgreement/ES/MCIU/RTI2018-093431-B-100 info:eu-repo/semantics/openAccess by http://creativecommons.org/licenses/by/3.0/es/ 4.997 2021 MULTIDISCIPLINARY SCIENCES 19 / 74 = 0.257 2021 Q2 T1 1.005 2021 Multidisciplinary 2021 Q1 info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion Herrerías, C.I. Universidad de Zaragoza (orcid)0000-0002-7272-8506 Hormigón, Z. (orcid)0000-0002-8805-4374 Mayoral, J.A. Universidad de Zaragoza (orcid)0000-0003-1570-4257 Salvatella, L. Universidad de Zaragoza (orcid)0000-0003-2010-9540 2013 765 Universidad de Zaragoza Dpto. Química Orgánica Área Química Orgánica 11, 1 (2021), 8777 [8 pp] Sci. rep. (Nat. Publ. Group) Scientific reports (Nature Publishing Group) 2045-2322 1119310 http://zaguan.unizar.es/record/110640/files/texto_completo.pdf Versión publicada 2364469 http://zaguan.unizar.es/record/110640/files/texto_completo.jpg?subformat=icon icon Versión publicada oai:zaguan.unizar.es:110640 articulos driver 2024-01-24-15:17:38 ARTICLE