High-Intensity Circular Dichroism of Head-to-tail Regioregular Poly(1,4-phenylene)s in the Aggregated State

Chemistry. 2024 Apr 22:e202400706. doi: 10.1002/chem.202400706. Online ahead of print.ABSTRACTCircular dichroism (CD) studies on poly(1,4-phenylene)s bearing a chiral side chain in the aggregated conditions were carried out. Little CD was observed in a solution form, while addition of a poor solvent into the polyphenylene solution induced aggregation and a strong CD was observed, accordingly. Applying the controlled degree of polymerization (DP) of poly(1,4-phenylene) in the use of bidentate diphosphine Chiraphos as a ligand for the nickel catalyst, the relationship of DP with CD strength was studied to reveal to show the highest CD at the DP = 84 (gabs = ca. 2 x 10-2). It was also found that the related aggregation was observed in good solvent 1,2-dichloroethane upon standing the solution at 4 °C for 3-23 days to observe gabs = ca. 10-1. Studies on the substituent effect of poly(1,4-phenylene) suggested that CD behaviors were dependent on the type of non-chiral substituent on the aromatic ring as well as the side-chain chirality.PMID:38647089 | DOI:10.1002/chem.202400706

Source: Chemistry - April 22, 2024 Category: Chemistry Authors: Rikuya Tanaka Seiha Yamaoka Shuichi Ikeda Kentaro Okano Masaki Horie Hideto Minami Nozomu Suzuki Atsunori Mori Source Type: research