{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,6,2]],"date-time":"2026-06-02T07:52:27Z","timestamp":1780386747978,"version":"3.54.1"},"reference-count":74,"publisher":"MDPI AG","issue":"3","license":[{"start":{"date-parts":[[2022,1,19]],"date-time":"2022-01-19T00:00:00Z","timestamp":1642550400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Nanomaterials"],"abstract":"<jats:p>The intrinsic dynamic and static nature of the \u03c0\u00b7\u00b7\u00b7\u03c0 interactions between the phenyl groups in proximity of helicenes 3\u201312 are elucidated with the quantum theory of atoms-in-molecules dual functional analysis (QTAIM-DFA). The \u03c0\u00b7\u00b7\u00b7\u03c0 interactions appear in C-\u2217-C, H-\u2217-H, and C-\u2217-H, with the asterisks indicating the existence of bond critical points (BCPs) on the interactions. The interactions of 3\u201312 are all predicted to have a p-CS\/vdW nature (vdW nature of the pure closed-shell interaction), except for 2Cbay-\u2217-7Cbay of 10, which has a p-CS\/t-HBnc nature (typical-HBs with no covalency). (See the text for definition of the numbers of C and the bay and cape areas). The natures of the interactions are similarly elucidated between the components of helicene dimers 6:6 and 7:7 with QTAIM-DFA, which have a p-CS\/vdW nature. The characteristic electronic structures of helicenes are clarified through the natures predicted with QTAIM-DFA. Some bond paths (BPs) in helicenes appeared or disappeared, depending on the calculation methods. The static nature of Ccape-\u2217-Ccape is very similar to that of Cbay-\u2217-Cbay in 9\u201312, whereas the dynamic nature of Ccape-\u2217-Ccape appears to be very different from that of Cbay-\u2217-Cbay. The results will be a guide to design the helicene-containing materials of high functionality.<\/jats:p>","DOI":"10.3390\/nano12030321","type":"journal-article","created":{"date-parts":[[2022,1,19]],"date-time":"2022-01-19T21:01:51Z","timestamp":1642626111000},"page":"321","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":6,"title":["Intrinsic Dynamic and Static Nature of \u03c0\u00b7\u00b7\u00b7\u03c0 Interactions in Fused Benzene-Type Helicenes and Dimers, Elucidated with QTAIM Dual Functional Analysis"],"prefix":"10.3390","volume":"12","author":[{"given":"Taro","family":"Nishide","sequence":"first","affiliation":[{"name":"Faculty of Systems Engineering, Wakayama University, 930 Sakaedani, Wakayama 640-8510, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Satoko","family":"Hayashi","sequence":"additional","affiliation":[{"name":"Faculty of Systems Engineering, Wakayama University, 930 Sakaedani, Wakayama 640-8510, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2022,1,19]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"1463","DOI":"10.1021\/cr200087r","article-title":"Helicenes: Synthesis and Applications","volume":"112","author":"Shen","year":"2012","journal-title":"Chem. 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