Several methods to address aromaticity in terms of nucleus-independent chem. shifts (NICS) are compared. These include NICS at the ring center NICS(0), NICS 1 .ANG. above the ring plane NICS(1), arom. ring current shielding (ARCS), and dissected NICS, i.e. NICS calcd. from selected pi orbitals NICSpi, again in the ring plane and 1 .ANG. above. The methods are tested on the basis of d.-functional theory (DFT) and the individual gauge for local orbitals (IGLO) technique. Applications include simple org. rings (C4H4, C4H42+, C6H6, C5H5-, C7H7+) and transition metal carbonyl complexed mols. Fe(CO)3C4H4 and Cr(CO)3C6H6. [on SciFinder (R)]
Title
Evaluation of aromaticity: A new dissected NICS model based on canonical orbitals
Published in
Physical Chemistry Chemical Physics
Volume
5
Issue
2
Pages
246-251
Date
2003
ISSN
1463-9076
Note
CAN 138:303727
22-2
Physical Organic Chemistry
Department of Physical Chemistry,University of Geneva,Geneva,Switz.
Journal
written in English.
71-43-2 (Benzene); 123-31-9 (Hydroquinone); 571-60-8 (1,4-Dihydroxynaphthalene); 1120-53-2 (Cyclobutadiene); 12078-17-0 (Tricarbonyl(cyclobutadiene)iron); 12082-08-5 ((Benzene)tricarbonylchromium); 12127-83-2 (Cyclopentadienide anion); 26811-28-9 (Cycloheptatrienyl cation); 175778-89-9 (1,3-Cyclobutadiene, radical ion(2+) Role: PRP (Properties) (evaluation aromaticity in terms of nucleus-independent chem. shifts)
Record creation date
2007-10-22
