Syntheses and Structures of Thiophene-Containing Cycloparaphenylenes and Related Carbon Nanohoops

Thiophene-containing cycloparaphenylenes (CPPs) bearing 8, 10, and 16 aromatic and heteroaromatic units in the macrocyclic ring structures were synthesized. Specifically, two and four thiophene-2,5-diyl units were incorporated into functionalized [6]- and [12]­CPP macrocyclic carbon frameworks, respectively. In addition, two 2,2′-bithiophene-5,5′-diyl units were inserted into a functionalized [6]­CPP carbon framework. The cyclic and differential pulse voltammetry and the UV–vis and fluorescence spectra of the fully aromatized macrocycles and their precursors exhibited interesting electrochemical and optical properties.