A Kekuléan benzenoid system is one with Kekulé structures. A fixed double (single) bond of a Kekuléan benzenoid system H is an edge belonging to all (none) of the Kekulé structures of H. Essentiall...A Kekuléan benzenoid system is one with Kekulé structures. A fixed double (single) bond of a Kekuléan benzenoid system H is an edge belonging to all (none) of the Kekulé structures of H. Essentially disconnected systems are Kekuléan pericondensed benzenoid systems with some fixed double or single bonds. In this paper a necessary and sufficient condition for a Kekuléan benzenoid system to be an essentially disconnected benzenoid system with fixed double bonds is given and rigorously proved.展开更多
文摘A Kekuléan benzenoid system is one with Kekulé structures. A fixed double (single) bond of a Kekuléan benzenoid system H is an edge belonging to all (none) of the Kekulé structures of H. Essentially disconnected systems are Kekuléan pericondensed benzenoid systems with some fixed double or single bonds. In this paper a necessary and sufficient condition for a Kekuléan benzenoid system to be an essentially disconnected benzenoid system with fixed double bonds is given and rigorously proved.
