122nd General Meeting of the KCS

Type Oral Presentation
Area Oral Presentation for Young Polymer Scientists
Room No. Room 325C+D
Time THU 10:20-:
Code POLY.O-8
Subject Extended Ladder-Type Benzo[k]tetraphene-Derived Oligomers
Authors Jongbok Lee, Lei Fang*
Chemistry, Texas A&M University, United States
Abstract Ladder-type fused aromatic materials have long been attracted and investigated due to their great electronic and optoelectronic properties with high thermal and chemical properties. In contrast with well-studied pentacene derivatives, which exhibit excellent electronic properties without air stability, constitutionally isomeric benzo[k]tetraphene (BTp) derivatives are stable under ambient conditions and have been barely explored due to the limited synthetic strategy to afford alternating fused rings and extremely low solubility of rigid ladder-type oligomers (i.e. longer than 7-fused rings). Herein, the synthesis of BTp derivatives up to 13-fused aromatic rings was achieved under thermodynamic control by employing reversible ring-closing olefin metathesis. This unique approach featured mild conditions and excellent efficiency, affording a series of BTp derivatives which have not been synthesized before. The good solubility of the BTp derivatives by introducing solubilizing groups at the end of the aromatic rings allowed a rigorous solution-based analysis and feasible processing of thin films using solution-casting techniques. Well-defined BTp systems enabled systematic study of the relationship between chain length and optical properties and effective conjugation length. Moreover, solid-state dynamics of rigid, coplanar BTP derivatives were investigated by grazing-incidence wide-angle x-ray scattering (GIWAXS) and solid-state UV-vis spectroscopy demonstrating the pivotal balance between intermolecular interaction and molecular mobility for optimized processing of highly ordered solids of these extended conjugated molecules.
E-mail jongbok.lee@chem.tamu.edu