β Scribed by Paolo Lazzeretti; Riccardo Zanasi
No coin nor oath required. For personal study only.
We present results of a quantum-mechanic& ulculation of electron current density, magetic susceptibrlity and proton . magnetic shielding in the cyclopropenyl cation, reflecting on the ring-current model. The current density induced m and out of the molecular plane by a perpendicular magnetic field is plotted, sbowving the existence of localized drstriiutions and paramagnetic circulations around the centre of the molecule. The peculiar magnetic properties of benzene and other aromatic molecules are usually rationalized in terms of the semi-classical ring-current model (RCM), which dates back to the early days of quantum mechanics [l-4]. According to this hypothesis, a uni-* Supported by the Centro di Calcolo Elettronico dell' Universiti di Modena and, in part, by the ItaIh CNR.
π SIMILAR VOLUMES
The transition structure (TS) for the reaction of formate anion with the hydride acceptor cyclopropenyl cation (CP' ) has been calculated with analytical gradients at an ab initio MO SCF level. The saddle point characterizing the reaction in vacuum was calculated with two basis sets: an extended (9s
## Abstract The equivalent dipole model of the ring current shift in benzene is shown to be equivalent to that of the wellβknown two current loop calculation. A network model of the ring current effect in the porphyrin system is described, using the doubleβdipole approximation, to give a calculatio