Naphthalene crystal packing, calculation

Ladder polymers have been of interest for many years, and an early paper on poly(per/-naphthalene) (49) using the VEH method combined with crystal packing calculations provided a band gap of 0.44 eV. With interchain overlap the calculated band gap decreases to 0.29 eV [81,82], The synthesis of polymer 49 by pyrolysis of 3,4,9,10-perylenetetracarboxylic dianhydride at temperatures between 530 and 900°C gave very highly conducting undoped films (a up to 15 S/cm) that were probably not the simple polymer 49 [82]. 

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