Magnetism in (Semi)Conducting Macrocycles of pi conjugated Polymers
Abstract
The objectives of this project involve the investigation of potential magnetic properties of macrocycles of pi-conjugated polymers. Thisresearch was initially motivated by the observation of extremely strong Faraday rotation, a nonlinear magneto-optic effect, in films of pristinehighly regioregular poly(3-alkylthiophene)s as well as by the subsequently observed ferromagnetic hysteretic behavior at low temperature (T <20k) in these polymers. Concomitantly nanoscopic doughnut structures ( ~12 nm) in spincoated thin films of these polymers were observed byAFM. Interestingly the magnetic properties and doughnut structures are strongly linked to the regioregularity of the poly(3-alkylthiophene)s. Allthese experimental observations led to the working hypothesis that the magnetic properties in the regioregular poly(3-alkylthiophene)s arelinked to these nanoscopic doughnut (supramolecular) structures. In this project the new hypothesis that macrocycles of (semi)conductingpolythiophenes would sustain fluctuating or persistent currents resulting in large magnetic moments and, consequently important magneticproperties in stable organic systems was investigated. Extensive DFT simulations (at different levels) of macrocycles of nm-dimensions weredone with the aim to guide an extensive program of synthesis. In collaboration with researchers at Yonsei University analysis of electronicstructures of macrocycles was investigated for their optical properties. The findings of these investigations suggested that such macrocycles,especially when oxidized, are organic quantum rings in analog to quantum dots and thus leads to a new field to explore.
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 09, 2016
- Accession Number
- AD1027330
Entities
People
- Andre Persoons
- Guy Koeckelberghs
- Thierry Verbiest
Organizations
- Katholieke Universiteit Leuven