Synthesis and magnetic characterization of monodisperse oligo(9,10-anthryleneethynylene)-based polyradicals with two pendant stable phenoxyls in one anthracene skeleton

We synthesized monodisperse oligo(9,10-anthryleneethynylene)s with pendant phenol residues at the 2- and 7-positions. The absorption maxima of oligomers shifted to longer wavelength with the degree of polymerization, suggesting a developed π-conjugation correlated with the chain length. The static magnetic susceptibility of the dimeric radical was measured using a SQUID magnetometer, and the 2J (J: spin coupling constant through the dianthrylacetylene unit) value of the dimeric radical was 34 cm−1, which agreed with the 2J value of the corresponding 2-substituted dimeric radical (31 cm−1). These large 2J values of the dimeric radicals can be explained from less steric hindrance between the side chain radicals and the backbone.

Graphical abstractMonodisperse oligo(9,10-anthryleneethynylene)s A2a–A5a were synthesized. The 2J (J: spin coupling constant through the dianthrylacetylene unit) value of the dimeric radicals B2c (2J = 34 ± 1 cm−1) indicates less steric hindrance between the side chain radicals and the poly(9,10-anthryleneethynylene) backbone.Figure optionsDownload full-size imageDownload as PowerPoint slide