Croatica Chemica Acta, Vol. 62 No. 1, 1989.
Izvorni znanstveni članak
Rationalisation of Relative »Ring-Current« Sizes in Polycyclic, Conjugated Hydrocarbons
C. W. Haigh
; Department of Chemistry, University College, Swansea, University of Wales, United Kingdom
R. B. Mallion
; Mathematical Institute, University of Oxford, United Kingdom
Sažetak
A theoretical basis is established for relating the incidence
of relatively 'high' and 'low' »ring-current« intensities (as encountered, for example, in the central rings of peropyrene (I) and
perylene (II), respectively) to intuitive Valence-Bond Resonance-
Theory (VB-RT) ideas about 'bond fixation'. In the present
treatment, this aim is not achieved by devising a »ring-current«
formalism that is itself actually based on a VB-RT wave-function:
the philosophy adopted here is (a) to identify, and classify, those
occasions on which simple Molecular-Orbital (MO) theory predicts
specific rings in conjugated hydrocarbons to have exceptionally
high and low »ring-currents«, and then (b) to use topological
arguments that rely simply on the carbon-atom connectivity of
the conjugated system in question to show that the situations
identified in (a), above, are just those in which the absence, or
presence, of VB-RT 'bond-fixation' is to be expected.
Ključne riječi
Hrčak ID:
175374
URI
Datum izdavanja:
30.3.1989.
Posjeta: 580 *