Double aromaticity in monocyclic carbon, boron, and borocarbon rings based on magnetic criteria
The double-arom. character of selected monocyclic carbon, boron, and borocarbon rings is demonstrated by refined nucleus-independent chem. shift (NICS) analyses involving the contributions of individual canonical MOs and their out-of-plane NICS tensor component (CMO-NICSzz). The double aromaticity considered results from two mutually orthogonal Hueckel p AO frameworks in a single mol. The familiar pi orbitals are augmented by the in-plane delocalization of electrons occupying sets of radial (rad) p orbitals. Such double aromaticity is present in B3-, C6H3+, C64+, C4B44+, C6, C5B2, C4B4, C2B8, B102-, B12, C10, C9B2, C8B4, C7B6, C6B8, and C14. Monocyclic C8 and C12 are doubly antiarom., as both the orthogonal pi and radial Hueckel sets are paratropic. Planar C7 and C9 monocycles have mixed arom. (pi) and anti-arom. (radial) systems. [on SciFinder (R)]
Keywords: Aromaticity (NICS; double aromaticity in monocyclic carbon ; boron ; and borocarbon rings based on magnetic criteria); Clusters (carbon; double aromaticity in monocyclic carbon ; boron ; and borocarbon rings based on magnetic criteria); Antiaromaticity; Electron delocalization; HOMO; LUMO; Magnetic properties (double aromaticity in monocyclic carbon ; boron ; and borocarbon rings based on magnetic criteria) ; double aromaticity monocyclic carbon boron borocarbon ring magnetic criteria
Physical Organic Chemistry
Department of Chemistry and Center for Computational Chemistry,University of Georgia,Athens,GA,USA.
written in English.
71-43-2 (Benzene); 2873-14-5 (1,3,5,7,9,11,13-Cyclotetradecaheptaene); 3227-76-7 (1,3,5,7,9-Cyclodecapentaene); 21894-87-1 (1,3,5-Cyclohexatriyne); 102508-17-8 (1,3,5,7-Cyclooctatetrayne); 132898-59-0 (1,2,3,4,5,6,7,8,9,10-Cyclodecadecaene); 145270-67-3 (2,4,6-Cycloheptatriyn-1-ylidene); 145270-68-4 (2,4,6,8-Cyclononatetrayn-1-ylidene); 145270-71-9 (1,3,5,7,9,11,13-Cyclotetradecaheptayne); 153621-55-7; 153621-56-8 (1,2,3,4,5,6,7,8,9,10,11,12,13,14-Cyclotetradecatetradecaene); 159416-43-0; 161054-30-4 (5-Benzenylium-1,3-diyl); 721966-43-4; 945841-43-0; 945841-44-1; 945841-45-2; 945841-46-3; 945841-47-4; 945841-48-5; 945841-49-6; 945841-50-9; 945842-18-2 (1,4-Diborepin); 945842-19-3 Role: PRP (Properties) (double aromaticity in monocyclic carbon, boron, and borocarbon rings based on magnetic criteria)
Record created on 2007-10-22, modified on 2016-08-08