Pure-Trigonal One-Dimensionally Extended Structures

Here there is a more substantive range of possibilities for long tubular polymers. From a chemical or physical viewpoint one anticipates that end-structures may be neglected. Mathematically one sees that the ends of the tube can be viewed to be capped 

The case of an infinite tnbe with all rings of size 6 is of special interest since they might be termed benzenoid. Of special note is the experimental preparation  

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