AUTHOR=Chi Zheng , Dong Hao , Shi Ganhui , Liu Pan , Ma Chenchen , Chen Xuegang TITLE=Synthesis and Characterization of Metallo-Supramolecular Polymers Based on Benzodipyrrolidone JOURNAL=Frontiers in Chemistry VOLUME=9 YEAR=2021 URL=https://www.frontiersin.org/journals/chemistry/articles/10.3389/fchem.2021.673834 DOI=10.3389/fchem.2021.673834 ISSN=2296-2646 ABSTRACT=

A simple route to the preparation of benzodipyrrolidone (BDP) based monomeric building blocks containing 2,2′:6′,2″-terpyridines is reported from a common precursor 4′-(4-pinacolatoboronphenyl)-2,2′:6′,2″-terpyridine via Suzuki coupling reaction. Self-assembly polymerization with ruthenium (II) ions under mild conditions yielded a series of novel metallo-supramolecular polymers with weak donor-acceptor (D-A) structures based on benzodipyrrolidone. The structure of the bridge connected BDP with terpyridine have a significant impact on the wavelength and intensity of the intramolecular charge transfer (ICT) absorption peak. The resulting metallo-polymers exhibited strong double absorption bands around 315 nm and 510 nm involved in π-π* transitions and ICT or metal to ligand charge transfer (MLCT) absorption bands. The forming of D-A structure and coordination with ruthenium (II) ions is favorable to narrow the energy gap and the energy gaps of the resulting metallo-supramolecular polymers are 2.01 and 1.62 eV, respectively.