Preparation and properties of some benzotropylium perchlorates

Abstract

The syntheses of a variety of substituted benzotropylium perchlorates, 6,8-polymethylenebenzotropylium perchlorates, and 6,6′:8,8′-bispolymethylenedi(benzotropylium perchlorate)s are described. In addition, evidence for the existence of 1a,3-polymethylenebenzohomotropylium cations is presented. By n.m.r. spectroscopy it has been shown that the positive charge (or charges) in these benzotropylium ions is delocalized over both the six- and the seven-membered rings.