ISSN:
1089-7690
Source:
AIP Digital Archive
Topics:
Physics
,
Chemistry and Pharmacology
Notes:
In this article, photoinduced infrared absorption (PIA-FTIR) and light induced electron spin resonance (LESR) measurements on an asymmetric carbazolyl substituted polydiacetylene (PDA), the poly{1-(N-carbazolyl) penta-1,3-diyn-5-ol} (polyCPDO) are presented. Results from both experimental techniques imply that contrary to other well-known polydiacetylene derivatives, in polyCPDO there exist only long-living, highly localized charged photoexcitations with spin 1/2 (g value∼2.0026), indicative for polaronic excitations. PolyCPDO also shows a strong dark ESR signal with the same g value as the LESR signal and with a Curie susceptibility of approximately 10−3 spins per CPDO monomer unit. This unusually high number of defects may come from intermediates of the polymerization. Furthermore, the photoexcited states of composites from polyCPDO mixed with a special solubilized methano-fullerene [6,6]-Phenyl C61–butyric acid methyl ester (PCBM) with excellent acceptor properties are investigated and compared with those of the pristine polymer. No enhancement of PIA-FTIR and LESR signals is found for these composites. It is therefore concluded, that even polyCPDO, which shows charged spin 1/2 photoexcitations, does not exhibit a photoexcited charge transfer to fullerenes as observed in other nondegenerate ground state conjugated polymer fullerene composites. © 1999 American Institute of Physics.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.480384
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