Premium
Electrons‐in‐a‐box model for conjugation in linear carbanions
Author(s) -
Ohwada Tomohiko,
Kagawa Hirotaka,
Ichikawa Hiroshi
Publication year - 1998
Publication title -
international journal of quantum chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.484
H-Index - 105
eISSN - 1097-461X
pISSN - 0020-7608
DOI - 10.1002/(sici)1097-461x(1998)68:1<65::aid-qua3>3.0.co;2-w
Subject(s) - carbanion , delocalized electron , electron , chemistry , kinetic energy , lone pair , conjugated system , ion , atomic physics , relaxation (psychology) , computational chemistry , physics , quantum mechanics , stereochemistry , molecule , organic chemistry , psychology , social psychology , polymer
Solving the constrained Hartree–Fock equation and using the method of the energy component analysis, we have determined the fundamental factor which causes the electrons at the negative center of conjugated carbanion to delocalize over the whole system. Constraint on the π‐electron flow between the anion center and polyethylenic system produces the electronic state that the lone‐pair electrons are localized at the anionic center. By doing so, a prominent increase in the kinetic energy of π electrons was observed. Such an increase was found to quantitatively fit in with that by the model that electrons are packed in a box. Thus, we could clearly show that delocalization of the carbanion in the polyethylenic system is brought forth by the relaxation of the kinetic energy pressure. We also examined conjugated carbodianion systems. Dianion involves repulsive interaction between anions causing less conjugation energy. Namely, conjugation itself is given by the release in the kinetic energy pressure, but, it is restrained by the electrostatic repulsion. © 1998 John Wiley & Sons, Inc. Int J Quant Chem 68: 65–72, 1998