Chain Length Modulated Dimerization and Cyclization of Terminal Thienyl-Blocked Oligopyrranes

Org Lett. 2022 Jul 29;24(29):5428-5432. doi: 10.1021/acs.orglett.2c02147. Epub 2022 Jul 15.

Abstract

Oxidation of thienyl-blocked bilane and pentapyrrane afforded chain length dependent products of the symmetric dimer D1 and the thienyloligopyrrin-appended pentaphyrin analogue P2, respectively, with the latter formed by simultaneous dimerization and cyclization. Coordination of D1 and P2 with Cu(II) afforded di- and monometallic complexes D1-Cu2 and P2-Cu, respectively. These compounds exhibit distinct NIR absorption, with the absorption tail of D1-Cu2 extended to ca. 1900 nm despite its smaller conjugation framework than that of P2-Cu.