Effect of the conjugation pathway on the electronic structures of p–π* conjugated polymers with fused borepin units. Issue 23 (28th May 2021)

• Record Type: Journal Article
• Authors: Adachi, Yohei; Arai, Fuka; Sakabe, Mitsuru; Ohshita, Joji
• Is Part Of: Polymer chemistry. Volume 12:Issue 23(2021)
• Page Start: 3471
• Page End: 3477
• Publication Date: 2021-05-28
• Subjects: Polymers -- Periodicals; Macromolecules -- Periodicals; Polymerization -- Periodicals; 547.705
• DOI: 10.1039/d1py00528f
• Languages: English
• ISSNs: 1759-9954

Abstract

Abstract : Borepin, an aromatic ring system with tricoordinate boron, was incorporated into p–π* conjugated polymers. The polymers exhibited characteristic optical responses upon the addition of cyanide anions in solution. Abstract : Among conjugated materials, p–π* conjugated polymers have attracted much attention due to their unique electronic structures derived from the orbital interaction between the empty p-orbital on boron and the π*-orbitals of the adjacent π-systems. On the other hand, borepin, an isoelectronic ring system of tropylium ions, has been investigated as an aromatic system containing heteroatoms. In this work, the first examples of p–π* conjugated polymers consisting of tetracyclic borepin structures with different conjugation pathways were prepared. Optical investigations revealed that the borepin polymers have more extended conjugations than conventional p–π* conjugated polymers. Furthermore, the two borepin polymers exhibited drastically different optical responses when cyanide was added to the solution. Photophysical measurements and DFT calculations disclosed the characteristic electronic effects of the borepin structures and the influence of different conjugation pathways.