45.13 Product Class 13: Biaryls 45.14 Product Class 14: Arylalkanes 45.15 Product Class 15: Poly(phenylenes) 45.16 Product Class 16: Poly(p-phenylenevinylenes) 45.17 Product Class 17: Poly(xylylenes) 45.18 Product Class 18: Polystyrenes 45.19 Product Class 19: Naphthalenes, Anthracenes, 9H-Fluorenes, and Other Acenes 45.20 Product Class 20: Cyclobutabenzenes, Biphenylenes, and [N]Phenylenes 45.21 Product Class 21: Phenanthrenes, Helicenes, and Other Angular Acenes 45.22 Product Class 22: Pyrenes, Circulenes, and Other Condensed Acenes 45.23 Product Class 23: Annulated Polycyclic Aromatic Hydrocarbons 45.24 Product Class 24: Pentalenes, s-Indacenes, as-Indacenes, Azulenes, and Heptalenes, and Their Benzo Derivatives 45.25 Product Class 25: Extended Polyaromatic Hydrocarbons: Graphite, Fullerene, and Carbon Nanotube Substructures 45.26 Product Class 26: Triphenylenes, Tetraphenylenes, and Related Compounds 45.27 Product Class 27: Calixarenes 45.28 Product Class 28: Mononuclear Cyclophanes 45.29 Product Class 29: Polynuclear Cyclophanes 45.30 Product Class 30: Conjugated Polyenes, Including Cyclic Polyenes That Are Not Fully Conjugated 45.31 Product Class 31: Macromolecular Conjugated Polyenes