Intramolecular charge transfer interaction in triptycene system was investigated. 9, 10- Dihydro-9, 10-o-benzenoanthracene-1, 4-dione (triptycenequinone) and its analogs were readily photoreduced with xanthene to give the corresponding hydroquinones and the adducts with two xanthenyl radicals. The chemically induced dynamic nuclear polarization examination and the corresponding thermal reaction proved the adducts to be originated ...