Tetrahedron

Conformational studies on helicenes—V: Alteration of the conformation of helicenes by annelation of benzo groups

WH Laarhoven, RJF Nivard

Index: Laarhoven,W.H.; Nivard,R.J.F. Tetrahedron, 1976 , vol. 32, p. 2445 - 2450

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Citation Number: 13

Abstract

Analysis of the NMR spectra of five heptahelicenes and some related compounds reveals that annelation of heptahelicene by one or more benzo groups results in a conformational change of the helix. The extent and direction of this change was deduced correctly from the NMR spectra by application only of the ring current theory and the influence of Van der Waals forces, as could be established from the X-ray analyses of heptahelicene and the ...