Leapfrog, Fries, Clar and phason-line-free fullerenes
Abstract
It is shown that the following are equivalent statements, all implying a properly closed π-shell in Hückel theory for a fullerene isomer: the given isomer is the leapfrog of another; it has a Fries Kekulé structure; it is a Clar polyhedron; it is without a phason line.