Title | Highly Emissive Excimers by 2D Compression of Conjugated Polymers |
Publication Type | Journal Article |
Year of Publication | 2016 |
Authors | Koo, B, Swager, TM |
Journal | ACS Macro Letters |
Volume | 5 |
Issue | 7 |
Pagination | 889 - 893 |
Date Published | Jul-07-2017 |
ISSN | 2161-1653 |
Abstract | Interactions between π-conjugated polymers are known to create ground-state aggregates, excimers, and exciplexes. With few exceptions, these species exhibit decreased fluorescence quantum yields relative to the isolated polymers in liquid or solid solutions. Herein, we report a method to assemble emissive conjugated polymer excimers and demonstrate their applicability in the detection of selected solvent vapors. Specifically, poly(phenylene ethynylene)s (PPEs) with amphiphilic side chains are organized in a Langmuir monolayer at the air–water interface. Compression of the monolayer results in the reversible conversion from a face-on organization of the π-system relative to the water to what appears to be an incline-stack conformation. The incline-stack organization creates a bright yellow emissive excimeric state with increases of 28% in relative fluorescence quantum yields to the face-on monolayer conformation. Multilayers can be transferred onto the glass substrate via a Langmuir–Blodgett method with preservation of the excimer emission. These films are metastable and the fluorescence reverts to a cyan color similar to the spectra obtained in solution and spin-cast films after exposure to selected solvent vapors. This behavior has practical utility as a fluorescence-based indicator for selected volatile organic compounds. |
URL | http://pubs.acs.org/doi/abs/10.1021/acsmacrolett.6b00491 |
DOI | 10.1021/acsmacrolett.6b00491 |
Short Title | ACS Macro Lett. |