Chemistry of Anthracene-Acetylene Oligomers XXVII. Iterative Synthesis, Structures, and Properties of Anthracene-Diacetylene Cyclic Oligomers with 10-Mesitylanthracene-1,8-diyl Units.

A series of cyclic oligomers consisting of 10-mesitylanthracene-1,8-diyl units and diacetylene linkers were synthesized as soluble π-conjugated compounds. Macrocyclic frameworks from dimer to octamer except heptamer were constructed from 1,8-diethynylanthracene derivatives by iterative coupling reactions. The rigid structure of the dimer, the strained structures of the trimer and the pentamer, and the belt-shaped structures of the other even-numbered oligomers were revealed by X-ray analysis and DFT calculations. The dynamic behavior of the cyclic oligomers was analyzed by observing variable-temperature 1 H NMR spectra. The UV/Vis and fluorescence spectra of these emissive cyclic compounds are discussed on the basis of the molecular structures.