{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,5,29]],"date-time":"2026-05-29T23:06:04Z","timestamp":1780095964051,"version":"3.54.0"},"reference-count":99,"publisher":"MDPI AG","issue":"1","license":[{"start":{"date-parts":[[2010,3,15]],"date-time":"2010-03-15T00:00:00Z","timestamp":1268611200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/3.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Symmetry"],"abstract":"<jats:p>The NICSzz-scan curves of aromatic organic, inorganic and \u201call-metal\u201d molecules in conjunction with symmetry-based selection rules provide efficient diagnostic tools of the \u03c3-, \u03c0- and\/or double (\u03c3 + \u03c0)-aromaticity. The NICSzz-scan curves of \u03c3-aromatic molecules are symmetric around the z-axis, having half-band widths approximately less than 3 \u00c5 with the induced diatropic ring current arising from Tx,y-allowed transitions involving exclusively \u03c3-type molecular orbitals. Broad NICSzz-scan curves (half-band width approximately higher than 3 \u00c5) characterize double (\u03c3 + \u03c0)-aromaticity, the chief contribution to the induced diatropic ring current arising from Tx,y-allowed transitions involving both \u03c3- and \u03c0-type molecular orbitals. NICSzz-scan curves exhibiting two maxima at a certain distance above and below the molecular plane are typical for (\u03c3 + \u03c0)-aromatics where the \u03c0-diatropic ring current overwhelms the \u03c3-type one. In the absence of any contribution from the \u03c3-diatropic ring current, the NICSzz(0) value is close to zero and the molecule exhibits pure \u03c0-aromaticity.<\/jats:p>","DOI":"10.3390\/sym2010284","type":"journal-article","created":{"date-parts":[[2010,3,15]],"date-time":"2010-03-15T12:15:15Z","timestamp":1268655315000},"page":"284-319","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":35,"title":["Diagnosis of the \u03c3-, \u03c0- and (\u03c3+\u03c0)-Aromaticity by the Shape of the NICSzz-Scan Curves and Symmetry-Based Selection Rules"],"prefix":"10.3390","volume":"2","author":[{"given":"Athanassios C.","family":"Tsipis","sequence":"first","affiliation":[{"name":"Laboratory of Inorganic and General Chemistry, Department of Chemistry, University of Ioannina, 451 10 Ioannina, Greece"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ioannis G.","family":"Depastas","sequence":"additional","affiliation":[{"name":"Laboratory of Applied Quantum Chemistry, Faculty of Chemistry, Aristotle University of Thessaloniki, 541 24 Thessaloniki, Greece"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Constantinos A.","family":"Tsipis","sequence":"additional","affiliation":[{"name":"Laboratory of Applied Quantum Chemistry, Faculty of Chemistry, Aristotle University of Thessaloniki, 541 24 Thessaloniki, Greece"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2010,3,15]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"957","DOI":"10.1016\/S0010-8545(01)00389-7","article-title":"Metalloaromaticity","volume":"219","author":"Masui","year":"2001","journal-title":"Coord. 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