Benzenoid links

摘要

In this paper, we study new configurations of benzenoid hydrocarbons, called benzenoid links. Roughly speaking, a primitive corofusene is a closed narrow hexagonal ribbon with out-of-plane curvature 0. A primitive corofusene or the union of disjoint primitive corofusenes in is called a benzenoid link. In this paper, we determine the minimum number of hexagons needed for a nontrivial benzenoid link in different senses. We also determine the structures of the smallest and the second smallest nontrivial benzenoid links of different types and their numbers of Kekule structures. We list all the benzenoid Hopf links of type III with 22–25 hexagons by their canonical codes in the appendix. Keywords Corofusenes - Benzenoid links - Hexagons - Benzenoid knots - Numbers of Kekule structures Weiling Yang was supported in part by NSFC Grant 10501038. Fuji Zhang was supported in part by NSFC Grant 10671162. Douglas J. Klein was supported by the Welch Foundation of Houston, Texas, through grant BD-0894.