1,4,10,13-Tetraoxa-7,16-diazacyclooctadecane, 7,16-di(1H-pyrin-6-yl)- 149246-42-4 1H-Purine, 6,6'-(1,4,10,13-tetraoxa-7,16-diazacyclooctadecane-7,16-diyl)bis- 6,6'-(1,4,10,13-Tetraoxa-7,16-diazacyclooctadecane-7,16-diyl)bis-1H-purine