Chemical Shifts of the [N]Phenylenes and Related Compounds

Autor:	Raymond L. Disch, Jerome M. Schulman, Paul von Ragué Schleyer, Haijun Jiao
Rok vydání:	1998
Předmět:	Crystallography Field (physics) Proton Chemistry Computational chemistry Phenylene Chemical shift Molecule Physical and Theoretical Chemistry Ring (chemistry) Antiaromaticity
Zdroj:	The Journal of Physical Chemistry A. 102:8051-8055
ISSN:	1520-5215 1089-5639
Popis:	Proton chemical shifts and nucleus-independent chemical shifts (NICS) have been computed for [N]phenylenes and related compounds using the GIAO/HF method. Proton chemical shifts calculated in the 6-31G* basis agree with measured values, where available, within 0.3 ppm. NICS values were calculated at the HF/321G level using B3LYP/6-31G* geometries. Both proton chemical shifts and NICS values show attenuation of aromatic and antiaromatic character in the six- and four-membered rings, respectively, in a manner dependent upon the positions of these rings in the molecule. These effects are greater in angular than in linear phenylenes. The central ring of a branched phenylene is found to be only slightly aromatic. The protons of the cyclic phenylenes resonate at slightly higher field than their angular counterparts. Both NICS and proton shifts of antikekulene suggest only slight additional antiaromatic character.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::5c0a5acde04e2c3bf4cac1e1f267dc78 https://doi.org/10.1021/jp982271q Zobrazit plný text záznamu