| Title: | Highly Emissive Excimers by 2D Compression of Conjugated Polymers |
| Address: | "daggerDepartment of Chemistry and double daggerDepartment of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States" |
| DOI: | 10.1021/acsmacrolett.6b00491 |
| ISSN/ISBN: | 2161-1653 (Electronic) 2161-1653 (Linking) |
| Abstract: | "Interactions between pi-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 pi-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" |
| Notes: | "PubMed-not-MEDLINEKoo, Byungjin Swager, Timothy M eng 2016/07/19 ACS Macro Lett. 2016 Jul 19; 5(7):889-893. doi: 10.1021/acsmacrolett.6b00491. Epub 2016 Jul 8" |
