C. Former, S. Becker, A. C. Grimsdale, K. Müllen
Cyclodehydrogenation of poly(perylene) to poly(quaterrylene): Toward poly(peri-naphthalene).
Macromolecules.  35(5), 1576-1582  (2002)

Cyclodehydrogenation of soluble polyperylenes gives polymers containing predominantly quaterrylene units by spectral analysis. Evidence for larger rylene units is also seen. These polymers represent important intermediates toward a poly(peri- naphthalene) (PPN). Reactions on model compounds suggest that the insolubility of polymers with larger rylene units is predominantly due to the rigidity of the polymer backbone.