{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,12]],"date-time":"2025-10-12T03:21:05Z","timestamp":1760239265484,"version":"build-2065373602"},"reference-count":39,"publisher":"MDPI AG","issue":"11","license":[{"start":{"date-parts":[[2020,10,22]],"date-time":"2020-10-22T00:00:00Z","timestamp":1603324800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100003407","name":"Ministero dell\u2019Istruzione, dell\u2019Universit\u00e0 e della Ricerca","doi-asserted-by":"publisher","award":["2017A4XRCA"],"award-info":[{"award-number":["2017A4XRCA"]}],"id":[{"id":"10.13039\/501100003407","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Symmetry"],"abstract":"<jats:p>Bicyclo[3.3.1]nonane-2,6-dione (1) and bicyclo[3.3.1]nona-3,7-diene-2,6-dione (2) have been examined by vibrational circular dichroism (VCD), which, as for most C2-symmetric systems, exhibits strong VCD signals. In the case of 2, VCD signals are stronger and sharper with several bisignate doublets; for 1, signals are less intense and broader. The VCD and IR spectra are excellently predicted by DFT calculations: only one conformer is present for 2, while for 1, three main conformers, related through concerted skeleton torsional motions are present (two of them being interchanged by C2-rotation). The VCD spectrum shows specific features for the different conformers, such that correct population factors are crucial for reproducing experimental data. Also, the TD-DFT prediction of ECD (electronic circular dichroism) spectra is good. By comparing the spectroscopic signature of the two molecules (both VCD and ECD) and by careful analysis of the theoretical results, the role of the C=C double bond in compound (2) is evidenced. The double bond contributes toward enhancing the CD response both electronically and vibrationally.<\/jats:p>","DOI":"10.3390\/sym12111752","type":"journal-article","created":{"date-parts":[[2020,10,23]],"date-time":"2020-10-23T02:01:42Z","timestamp":1603418502000},"page":"1752","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":3,"title":["Vibrational Circular Dichroism Detects Symmetry Breaking due to Conformational Mobility in C2-Symmetry Chiral Molecules and Provides Further Insight into Inter-Chromophoric Interactions"],"prefix":"10.3390","volume":"12","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-3819-6438","authenticated-orcid":false,"given":"Giuseppe","family":"Mazzeo","sequence":"first","affiliation":[{"name":"Dipartimento di Medicina Molecolare e Traslazionale, Universit\u00e0 di Brescia, Viale Europa 11, 25123 Brescia, Italy"}]},{"given":"Sergio","family":"Abbate","sequence":"additional","affiliation":[{"name":"Dipartimento di Medicina Molecolare e Traslazionale, Universit\u00e0 di Brescia, Viale Europa 11, 25123 Brescia, Italy"},{"name":"Istituto Nazionale di Ottica (INO), C.N.R., Research Unit of Brescia, via Branze 45, 25123 Brescia, Italy"}]},{"given":"Stefan E.","family":"Boiadjiev","sequence":"additional","affiliation":[{"name":"Regional Health Inspectorate, 7 Prince Al. Battenberg I Str., 5800 Pleven, Bulgaria"}]},{"given":"David A.","family":"Lightner","sequence":"additional","affiliation":[{"name":"Chemistry Department, University of Nevada, Reno, NV 89557, USA"}]},{"given":"Giovanna","family":"Longhi","sequence":"additional","affiliation":[{"name":"Dipartimento di Medicina Molecolare e Traslazionale, Universit\u00e0 di Brescia, Viale Europa 11, 25123 Brescia, Italy"},{"name":"Istituto Nazionale di Ottica (INO), C.N.R., Research Unit of Brescia, via Branze 45, 25123 Brescia, Italy"}]}],"member":"1968","published-online":{"date-parts":[[2020,10,22]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"3235","DOI":"10.1021\/ja00035a011","article-title":"Homoconjugation and Transannular Orbital Interactions Detected by Photoelectron and 13C-NMR Spectroscopy. Bicyclo[3.3.1]nonane-2,6-dione and bicyclo[3.3.1]nona-3,7-diene-2,6-dione","volume":"114","author":"Doerner","year":"1992","journal-title":"J. Am. Chem. 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