Fluorescent, electroactive, thermally stable triphenylamine- and naphthalene-based polyimides for optoelectronic applications

Abstract

To tune the photophysical properties of polyimides (PIs), a diamine containing naphthalene and triphenylamine units, N-1-(4-aminophenyl)-N-1-[(4-naphthalene-2-yloxy) phenyl]benzene-1,4-diamine (DA), was synthesized. A series of fluorescent electroactive new PIs from synthesized DA were prepared with conventional thermal imidization with dianhydride. The selected dianhydride were used to study and compare the effects of rigid planar phenyl, flexible phenoxy, and nonplanar flexible hexafluoroisopropyidene and carbonyl groups in the main polymer backbone on the optoelectronic properties and processability of materials. The structures of the synthesized diamine and its PIs were evaluated by spectral and CHNS elemental analysis. The optoelectronic and thermal properties of PIs revealed intense blue-light emission (428-477 nm), a low oxidation potential (0.3-1.3 V), and a lower highest occupied molecular orbital-lowest unoccupied molecular orbital gap (2.92-3.21 eV). The observed behavior and properties of our synthesized PIs suggest their potential as future hole-transport materials in optoelectronic applications. (C) 2016 Wiley Periodicals, Inc.