After initial reports of a "homoaromatic" structure for the tris-homocyclopropenyl cation were published by Winstein, many groups began to report observations of similar compounds. One of the best studied of these molecules is the homotropylium cation, the parent compound of which was first isolated as a stable salt by Pettit, et al. in 1962, when the group reacted cyclooctatraene with strong acids. Much of the early evidence for homoaromaticity comes from observations of unusual NMR properties associated with this molecule.