Highly Stable Heptacene

Abstract

Significance: A highly stable heptacene derivative (9) has been synthesized. This compound is stabilized by the thioaryl substituents as well as by the o-dimethylphenyl groups. The only previous reports of functionalized heptacenes contained silylethynyl substituents on the central ring.Comment: The authors utilize the remarkable stability conferred by the thioaryl substituents which protect the central ring from photooxidation. Compound 9 has a small HOMO-LUMO gap of 1.37 V, calculated based on the onset of its longest wavelength absorption. S S Br Br Br Br or O O KI, DMF, reflux O O R R O O 4 R = 4-(t-butyl)phenyl, 65% yield 5 R = 4-(t-butyl)phenylthio, 57% yield 1 2 3 O O R R O O O O R R O O 1. NaBH 4 , THF 2. SnCl 2 , 1,4-dioxane 10% HCl R R R R 4 , 5 6 R = 4-(t-butyl)phenyl 7 R = 4-(t-butyl)phenylthio 4 , 5 8 R = 4-(t-butyl)phenyl 9 R = 4-(t-butyl)phenylthio Br Br Br Br SYNFACTS Contributors: