High-Triplet-Energy Polymers via RAFT 3 Polymerization: Synthesis and Properties

Abstract

RAFT polymerization of a series of styrene-type dibenzoheterocyclic monomers bearing carbazole, phenoxazine, 9,9-dimethylacridane and phenothiazine moieties using S-dodecyl-S′-(α,α′-dimethyl-α′′-acetic acid)trithiocarbonate as a chain transfer agent has been investigated. The corresponding polymers with the controlled molar mass of up to 30,000 g mol−1 with low to moderate dispersity (Đ = 1.2–1.6) were synthesized. The thermal, photophysical and electrochemical properties of the prepared polymers have been investigated using their solutions, films and in silico to establish the structure-properties relationship. The synthesized polymers were characterized by high values of HOMO (up to −5 eV), singlet (up to 3.8 eV) and triplet (up to 3.2 eV) energies, which are responsible for their unique properties such as formation of excimers with CHCl3 and dichloromethane or the ability to undergo coupling via electrooxidation in case of poly(9,9-dimethyl-10-(4-vinylphenyl)-9,10-dihydroacridan). Subsequently, two series of OLEDs based on the synthesized polymers were fabricated in order to study the charge-injecting and charge-transporting properties of these materials as well as to evaluate their performance in solution-processable diodes.