Luminescence of molecular and block copolymeric 2,7-bis(phenylethenyl)- fluorenones; identifying green-band emitter sites in a fluorene-based luminophore

Date

2007-06-26

Author

RATHNAYAKE, Hemali P.
Çırpan, Ali
KARASZ, Frank E.
ODOI, Michael Y.
HAMMER, Nathan I.
BARNES, Michael D.
LAHTI, Paul M.

Metadata

Show full item record

This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Item Usage Stats

91
views

0
downloads

2,7-Bis(3,4,5-trimethoxyphenylethenyl)fluorenone (OFOPV) and a segmented oligomer analogue linking OFOPV units with polymethylene flexible spacersalt-poly(2,6-dimethoxylphenylene-4-vinylene-[9-fluorenone-2-yl-7-vinylene]3,5-dimethoxyphenylene-4-[1,6-hexanedioxyl]) (pFOPV)were synthesized and their luminescence properties studied. Solution-phase photoluminescence (PL) of OFOPV and pFOPV shows concentration-dependent relative intensities of a fine-structured higher energy band and a featureless lower energy band, consistent with solution excimer formation. Neat film PL and electroluminescence (EL) spectra using 100% OFOPV and pFOPV emitter layers show red emission bands (λmax ∼ 610 nm). Solid film PL spectra of OFOPV diluted in PMMA or Zeonex are significantly blue-shifted relative to the neat film spectra. PL and EL spectra of 2,7-bis(3,4,5-trimethoxyphenylethenyl)-9,9-diethylfluorene (OFPV) blended with <1% by weight of OFOPV gives significant green region (g-band) emission in addition to the normal blue emission of OFPV. Monomeric OFOPV produced by adventitious oxidation is therefore identified as giving g-band emission in thermally stressed OFPV-based OLEDs, due to intermolecular energy transfer from OFPV excitons to lower energy OFOPV. The red emission in neat solid-phase OFOPV and pFOPV appear to arise from fluorenone-type excimers that do not play a direct role in g-band emission in this case.

Subject Keywords

Materials Chemistry, General Chemistry, General Chemical Engineering

URI

https://hdl.handle.net/11511/34605

Journal

Chemistry of Materials

DOI

https://doi.org/10.1021/cm070552h

Collections

Department of Chemistry, Article

Suggestions

OpenMETU
Core

Luminescence of fluorenes 2,7-conjugatively extended with pyrenylvinylene and pyrenylvinylene-phenylenevinylene Çırpan, Ali; LAHTI, Paul M.; KARASZ, Frank E. (Royal Society of Chemistry (RSC), 2007-01-01) 2,7-Bis(1'-pyrenylvinylene)-9,9-diethylfluorene (1) and 2,7-bis(1'-pyrenylvinylene- 4 ''-phenylenevinylene)-9,9-diethylfluorene (2) were synthesized and their static luminescence behavior assessed. They show solution photoluminescence (PL) maxima in chloroform at 475 nm and 467 nm, with quantum efficiencies of 54% and 52%, respectively. Double-layer LED devices with configuration ITO/PEDOT-PSS/(1 or 2)/Ca-Al emitted blue-green light with turn-on voltages of 2.5 V and emission maxima at 500 nm (2.48 eV); the...
Proquinoidal-Conjugated Polymer as an Effective Strategy for the Enhancement of Electrical Conductivity and Thermoelectric Properties Tam, Teck Lip Dexter; Ng, Chee Koon; Lim, Siew Lay; Yıldırım, Erol; Ko, Jieun; Leong, Wei Lin; Yang, Shuo-Wang; Xu, Jianwei (American Chemical Society (ACS), 2019-10-22) P-doping of conjugated polymers requires electron transfer from the conjugated polymer to the p-dopant. This implies that the highest occupied molecular orbital (HOMO) of the conjugated polymer has to be higher than the lowest unoccupied molecular orbital (LUMO) of the p-dopant. Although commonly used p-dopants such as 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane (F4TCNQ) have a low LUMO of -5.24 eV, most conjugated polymers used in high-performance field-effect transistors are donor- acceptor-type ...
New, highly stable electrochromic polymers from 3,4-ethylenedioxythiophene-bis-substituted quinoxalines toward green polymeric materials Durmus, Asuman; Günbaş, Emrullah Görkem; Toppare, Levent Kamil (American Chemical Society (ACS), 2007-12-11) Two new highly stable electrochromic polymers, poly(5,8-bis(2,3-dihydrothieno[3,4-b][1,4]dioxin-5-yl)-2,3-di(thiophen-2-yl)quinoxaline) (PDETQ) and poly (5,8-bis(2,3 -dihydrothieno[3,4-b][ 1,4]dioxin-5yl)quinoxaline) (PDEQ) were synthesized, and their potential use as neutral state green polymeric materials was investigated. Spectroelectrochemistry showed that both polymers reveal two distinct absorption bands as expected for this type of donor-acceptor polymer, at 410 and 660 nm for PDEQ and 405 and 780 nm...
Optimizing LED properties of 2,7-Bis(phenylethenyl)fluorenes RATHNAYAKE, Hemali P.; Çırpan, Ali; LAHTI, Paul M.; KARASZ, Frank E. (American Chemical Society (ACS), 2006-01-24) (E,E)-2,7-Bis(3,4,5-trimethoxyphenylethenyl)fluorene 1, and a segmented copolymer 2 composed of the same chromophore alternated with nonconjugated 1,6-hexanediyl (alt-oligo(2,6-dimethoxylphenylene-4-vinylene-[9,9-diethylfluoren-2-yl-7-vinylene]-3,5-dimethoxy-phenylene-4-[1,6-hexanedioxyl]) were synthesized. They have solution photoluminescence emission maxima at 420-460 nm, with quantum efficiencies of 0.93 and 0.68, respectively, in chloroform. Electroluminescent spectra in an LED configuration ITO/PEDOT-P...
THERMAL AND MASS DIFFUSIVITY FROM DYNAMIC SINGLE PELLET EXPERIMENTS DOGU, G; CABBAR, C; Doğu, Timur (Informa UK Limited, 1991-01-01) The single-pellet moment techniques previously developed for the evaluation of effective diffusion coefficient and effective thermal conductivity of a porous solid are combined and a procedure is proposed for the simultaneous evaluation of these constants from a single set of pulse response experiments. It is shown that both temperature and concentration response curves can be measured from a single pulse of oxygen injected into hydrogen carrier gas flowing past a catalyst pellet. It is shown that the zerot...

Citation Formats

H. P. RATHNAYAKE et al., “Luminescence of molecular and block copolymeric 2,7-bis(phenylethenyl)- fluorenones; identifying green-band emitter sites in a fluorene-based luminophore,” Chemistry of Materials, pp. 3265–3270, 2007, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/34605.