{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,6,29]],"date-time":"2026-06-29T23:42:59Z","timestamp":1782776579199,"version":"3.54.5"},"reference-count":59,"publisher":"MDPI AG","issue":"24","license":[{"start":{"date-parts":[[2025,12,17]],"date-time":"2025-12-17T00:00:00Z","timestamp":1765929600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Polish high-performance computing infrastructure PLGrid","award":["PLG\/2025\/018764"],"award-info":[{"award-number":["PLG\/2025\/018764"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Materials"],"abstract":"<jats:p>Thermal [2+2] cycloaddition (22CA) reactions of perfluorobicyclo[2.2.0]hex-1(4)-ene (PFBHE) and bicyclo[2.2.0]hex-1(4)-ene (BHE) with ethylene, benzene and styrene were investigated through the Molecular Electron Density Theory (MEDT) at the UM06-2X\/6-311G(d,p) level in benzene. Scrutiny of the DFT-based reactivity indices indicates that the presence of the eight fluorines in PFBHE notably expands the electrophilic nature of this species, participating in polar reactions. These 22CAs proceed through a stepwise mechanism, while the non-polar 22CA reaction of BHE with ethylene requires high energy around 26.6 kcal\u00b7mol\u22121, the polar 22CA reaction of PFBHE with styrene requires a low activation energy of 13.2 kcal\u00b7mol\u22121. The polar 22CA reaction of PFBHE with benzene presents the highest activation energy, 28.3 kcal\u00b7mol\u22121, because of the loss of its aromatic character. Scrutiny of the electron localization function (ELF) at the TSs associated with the first step points that the creation of the C1\u2013C3 bond set about, while that at the TSs associated with the ring-closure means that the creation of the C2\u2013C4 bond has not started yet. At the end, a Relative Interacting Atomic Energy (RIAE) study of these thermal 22CA processes shows that while at the non-polar TS1a-I both interacting frameworks are electronically destabilized, at the polar TS1a-IV, the hefty global electron density transfer (GEDT) goes ahead towards PFBHE, causing a strong electronic stabilization of this framework, markedly reducing the RIAE activation energy.<\/jats:p>","DOI":"10.3390\/ma18245675","type":"journal-article","created":{"date-parts":[[2025,12,18]],"date-time":"2025-12-18T09:15:21Z","timestamp":1766049321000},"page":"5675","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":1,"title":["Thermal [2+2] Cycloaddition Reactions of Perfluorobicyclo[2.2.0]hex-1(4)-ene with Ethylene, Benzene and Styrene: A MEDT Perspective"],"prefix":"10.3390","volume":"18","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-0636-7914","authenticated-orcid":false,"given":"Agnieszka","family":"K\u0105cka-Zych","sequence":"first","affiliation":[{"name":"Cracow University of Technology, Faculty of Chemical Engineering and Technology, Department of Organic Chemistry and Technology, Warszawska 24, 31-155 Cracow, Poland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-2023-0108","authenticated-orcid":false,"given":"Luis R.","family":"Domingo","sequence":"additional","affiliation":[{"name":"Independent Researcher, Avd. Tirso de Molina 20, 46015 Valencia, Spain"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2025,12,17]]},"reference":[{"key":"ref_1","unstructured":"Carruthers, W. (1978). Some Modern Methods of Organic Synthesis, Cambridge University Press. [2nd ed.]."},{"key":"ref_2","unstructured":"Carruthers, W. (1990). Cycloaddition Reactions in Organic Synthesis, Pergamon."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"98","DOI":"10.1002\/jlac.19284600106","article-title":"Synthesen in der hydroaromatischen Reihe","volume":"460","author":"Diels","year":"1928","journal-title":"Justus Liebigs Ann. Chem."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"600","DOI":"10.1007\/s10593-025-03383-x","article-title":"Synthesis of bis-het(aryl) systems via domino reaction involving (2E,4E)- 2,5-dinitrohexa-2,4-diene: DFT mechanistic consideration","volume":"60","author":"Kula","year":"2024","journal-title":"Chem. Heterocycl. 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