Luminescent Poly Research Articles

Chemical Modification of a Luminescent Poly(phenylenevinylene)-Amylose Composite

ADVERTISEMENT RETURN TO ISSUEPREVNoteNEXTChemical Modification of a Luminescent Poly(phenylenevinylene)-Amylose CompositeKazumi Tamura†, Katsuhiro Maeda†§, and Eiji Yashima*†‡View Author Information Department of Molecular Design and Engineering, Graduate School of Engineering, Nagoya University, Chikusa-ku, Nagoya 464-8603, Japan, Yashima Super-structured Helix Project, Exploratory Research for Advanced Technology (ERATO), Japan Science and Technology Agency (JST), 101 Creation Core Nagoya, 2266-22 Anagahora, Moriyama-ku, Nagoya 463-0003, Japan* To whom correspondence should be addressed. E-mail: [email protected]†Department of Molecular Design and Engineering, Graduate School of Engineering, Nagoya University.‡Yashima Super-structured Helix Project, Exploratory Research for Advanced Technology (ERATO), Japan Science and Technology Agency (JST).§Present address: Graduate School of Natural Science and Technology, Kanazawa University, Kakuma-machi, Kanazawa 920-1192, Japan.Cite this: Macromolecules 2008, 41, 13, 5065–5069Publication Date (Web):June 4, 2008Publication History Received11 April 2008Revised28 April 2008Published online4 June 2008Published inissue 1 July 2008https://doi.org/10.1021/ma800811vCopyright © 2008 American Chemical SocietyRIGHTS & PERMISSIONSArticle Views676Altmetric-Citations7LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit Read OnlinePDF (559 KB) Get e-AlertsSupporting Info (1)»Supporting Information Supporting Information SUBJECTS:Chemical modification,Composites,Diodes,Luminescence,Thin films Get e-Alerts

Synthesis and Characterization of Luminescent Rod-Coil Poly[2,7-(9,9- Dihexylfluorene)] - Block-Poly(2-(Dimethylamino) Ethyl Methacrylate) by Atom Transfer Radical Polymerization

The synthesis, morphology, and photophysical properties of Poly[2,7-(9,9-dihexyl fluorene)]- block-poly(2-(Dimethylamino) ethyl methacrylate) (PF-b-PDMAEMA) copolymers in various mixed solvents, i.e., THF/MeOH, DMF/MeOH, and 1,4-Dioxane/MeOH, with methanol contents of 0, 10, 25, 50, 75, 90 vol.% were reported. TEM images showed that different aggregate morphologies of PF-b-PDMAEMA, including spherical and large compound micelles, cylinder, nanorods, long stick-like structure, could be prepared by introducing different amount of methanol into the copolymer/solvent system. The results indicated that aggregate morphologies of PF-b-PDMAEMA, which obtained from various coil lengths and mixed solvents, had a great influenced on the optical and photoluminescence properties of the prepared PF-b-PDMAEMA copolymers.

Synthesis and optical properties of blue luminescent poly(2,6‐naphthalene)s

Blue luminescent 2,6-naphthalene-based homopolymer and copolymers were synthesized by Yamamoto method using Ni(cod)2 and Pd-catalyzed Suzuki coupling, respectively. Two kinds of substituents, an electron rich 3,6,9-trioxaundecyloxy (a) and a bulky 2-isopropyl-5-methylhexyloxy (b), significantly suppressed excimeric emissions of polynaphthalenes in film states, which achieved pure blue photoluminescence.

Synthesis and characterization of organosoluble luminescent poly(amide-imide)s

Poly(amide-imide)s (PAIs) were synthesized from 9,9’-bis(4-aminophenyl)fluorene (APF) and different diimide-dicarboxylic acids (DIDA). The aromatic fluorene group is isolated by DIDA. The structure of the polymer was confirmed by 1H NMR, 13C NMR, and FTIR. These PAIs were soluble in polar aprotic solvents, such as N-methyl-2-pyrrolidone, N,N-dimethylacetamide, N,N-dimethylformamide, and dimethyl sulfoxide. The crystallinity of the polymers is estimated by means of wide-angle X-ray diffraction. The resultant PAIs exhibited nearly amorphous nature. Thermal stability of the PAIs was characterized by differential scanning calorimetry and thermogravimetric analysis. No obvious glass transition temperatures were detected and the 5% weight loss temperatures of the PAIs were in the range 296–453 °C in nitrogen. The optical properties were studied by Ultraviolet–visible (UV/VIS) spectra and photoluminescent (PL) in solution and film states. The results show similar absorbance and emission to those of the constituting APF monomer. The highest occupied molecular orbital (HOMO) and lowest occupied molecular orbital (LUMO) were estimated from cyclic voltammograms. The values of HOMO and LUMO are -6.67 to -6.72, and -3.54 to -3.58, respectively. Their optical and electrochemical properties are not changed significantly by different DIDA.

Thermally Stabilized Blue Luminescent Poly(p‐phenylene)s Covered with Polyhedral Oligomeric Silsesquioxanes

AbstractA novel series of poly(p‐phenylene)s (PPPs) with polyhedral oligomeric silsesquioxanes (POSSs) on their side chains was prepared. The obtained POSS‐modified PPPs are as follows: 25POSS‐PPP (2b, containing 25 mol‐% of POSS units in all side chains), 50POSS‐PPP (2c, containing 50 mol‐% of POSS units in all side chains), 100POSS‐PPP (2d, containing 100 mol‐% of POSS units in all side chains), and 0POSS‐PPP (2a, as a blank polymer). Films polymer 2d showed the same absorption and photoluminescence (PL) spectra as those in CHCl3 solution, indicating that bulky POSS units strongly suppressed intermolecular aggregation of the PPP backbone. Polymer 2d showed the same PL spectra even after thermal annealing at 150 °C for 6 h. This enhancement of PL stability is due to the significant effect of the bulky POSS units.magnified image

Poly(9,9‐dioctylfluorene) Nanowires with Pronounced β‐Phase Morphology: Synthesis, Characterization, and Optical Properties

High aspect ratio, luminescent poly(9,9-dioctylfluorene) nanowires are synthesized by template wetting. Optical spectroscopic characterization indicates the formation of a significant fraction of the polymer β-phase. The results indicate that the wires essentially act as self-doped 1D nanostructures in which the PFO β-phase dominates the luminescence behavior following optical, electrochemical or electrical excitation.

Synthesis and optoelectronic properties of luminescent poly(p‐phenylenevinylene) derivatives containing electron‐transporting 1,3,4‐oxadiazole groups

AbstractThree random copolymers (P1–P3) comprising phenylenevinylene and electron‐transporting aromatic 1,3,4‐oxadiazole segments (11, 18, 28 mol %, respectively) were prepared by Gilch polymerization to investigate the influence of oxadiazole content on their photophysical, electrochemical, and electroluminescent properties. For comparative study, homopolymer poly[2‐methoxy‐5‐(2′‐ethylhexyloxy)‐1,4‐p‐phenylenevinylene] (P0) was also prepared by the same process. The polymers (P0–P3) are soluble in common organic solvents and thermally stable up to 410 °C under a nitrogen atmosphere. Their optical properties were investigated by absorption and photoluminescence spectroscopy. The optical results reveal that the aromatic 1,3,4‐oxadiazole chromophores in P1–P3 suppress the intermolecular interactions. The HOMO and LUMO levels of these polymers were estimated from their cyclic voltammograms. The HOMO levels of P0–P3 are very similar (−5.02 to −5.03 eV), whereas their LUMO levels decrease readily with increasing oxadiazole content (−2.7, −3.08, −3.11, and −3.19 eV, respectively). Therefore, the electron affinity of the poly(p‐phenylenevinylene) chain can be gradually enhanced by incorporating 1,3,4‐oxadiazole segments. Among the polymers, P1 (11 mol % 1,3,4‐oxadiazole) shows the best EL performance (maximal luminance: 3490 cd/m2, maximal current efficiency: 0.1 cd/A). Further increase in oxadiazole content results in micro‐phase separation that leads to performance deterioration. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 4377–4388, 2007

Theoretical Investigations on the Electronic and Optical Properties of Luminescent Poly(alkylthiophene‐co‐pyridine)

AbstractQuantum‐chemical techniques were applied to investigate a series of conjugated polymers: poly(3‐octylthien‐2,5‐ylene‐co‐pyrid‐2,6‐ylene) (p1), poly[pyrid‐2,6‐ylenebis(3‐octylthien‐2,5‐ylene)] (p2) and poly[pyrid‐2,5‐ylene‐ bis(3‐octylthien‐2,5‐ylene)] (p3) comprising alternating π‐excessive 3‐alkylthiophene and π‐deficient meta‐ or para‐linked pyridine moieties. Their ground state and excited state structures were optimized with density functional theory B3LYP method, and the optical properties were calculated by the time‐dependent density functional theory (TD‐DFT) and ZINDO/S methods. Their HOMO‐LUMO gaps (ΔH‐L), the lowest excitation energies (Eex), ionization potentials (IP) and electron affinities (EA) were obtained by extrapolating those of the polymers to the inverse chain length equal to zero (1/n=0). The calculated results showed that the decrease of pyridylene content increased the HOMO level and decreased the LUMO level while the para‐linkage further contributed to it. The IP are in the order: p1>p2>p3 but EA are: p1<p2<p3. In addition, the decrease of the pyridylene content and the para‐linked pyridylene in the backbone of the polythiophene resulted in a narrowed energy gap and bathochromic absorption and emission peaks.

Synthesis and Characterization of the Luminescent Poly[2-decyloxy-5-(2′,5′-bis(decyloxy)phenyl)-1,4-phenylenevinylene

A new soluble luminescent poly[2-decyloxy-5-(2′,5′-bis(decyloxy)phenyl)-1,4-phenylenevinylene] (DBDP-PPV) is prepared by the dehydrohalogenation of 1,4-bis(bromomethyl)-2-decyloxy-5-(2′,5′-bis(decyloxy)phenyl) benzene (as monomer) in this study. The above monomer bearing decyloxy and 2′,5′-bis(decyloxy)phenyl substituents was prepared via such chemical reactions as alkylation, bromination, and Suzuki coupling reactions. The two asymmetric substituents on the phenylene ring make the DBDP-PPV soluble in organic solvents and eliminate the tolan-bis-benzyl (TBB) structure defects. The structure and properties of the DBDP-PPV are examined by 1H-NMR, FT-IR, UV/Vis, TGA, photoluminescence (PL), and electroluminescence (EL) analyses. The DBDP-PPV film exhibits a PL peak at 519 nm. With the DBDP-PPV acting as a light-emitting polymer, a device is fabricated with a sequential lamination of ITO/PEDOT/DBDP-PPV/Ca/Ag. The EL spectrum of the device shows a maximum emission at 507 nm. The turn on voltage of the device is about 15.6 V. Its maximum brightness is 4.67 cd/m2 at a voltage of 16.8 V.

Synthesis and characterization of the soluble luminescent poly[2-decyloxy-5-(4’-ethoxyphenyl)-1,4-phenylenevinylene

A new soluble luminescent poly[2-decyloxy-5-(4′-ethoxyphenyl)-1,4-phenylene-vinylene] (DEP-PPV) is prepared by the dehydrohalogenation of 1,4-bis(bromo-methyl)-2-decyloxy-5-(4′-ethoxyphenyl) benzene in this study. The structure and properties of the DEP-PPV are examined by 1H NMR, FT-IR, UV/VIS, TGA, photoluminescence (PL), and electroluminescence (EL) analyses. The incorporation of a decyloxy substituent in the 2-position of phenylene ring makes the DEP-PPV soluble in organic solvents and eliminates tolan-bis-benzyl structure defects. The energy band gap of DEP-PPV in tetrahydrofuran is 2.36 eV. The PL peak of DEP-PPV solution shifts to higher wavelength as the solution concentration increases. The PL spectrum of the DEP-PPV film shows a peak at 546 nm and the one of the pristine PPV film does at 540 nm. This red shift of PL peak for the DEP-PPV as compared with that for the PPV indicates that the incorporation of a conjugated ethoxyphenyl group on the phenylene ring can increase the conjugation length of phenylenevinylene units in the DEP-PPV. With the DEP-PPV acting as a light-emitting polymer, a device is fabricated with a sequential lamination of ITO/PEDOT/DEP-PPV/Ca/Ag. The EL spectrum of the device shows a maximum emission at 530 nm, which corresponds to the yellowish-green light. The turn-on voltage of the device is about 16 V. Its maximum brightness is 46 cd/m2 at a voltage of 18 V.

Luminescent poly( p-phenylenevinylene) with 4-methylcoumarin side groups: Synthesis, optical properties and photo-crosslinking behaviors

Poly( p-phenylenevinylene) (PPV) derivatives HOPPV and COUPPV, containing hexyloxy side groups and 7-oxy-4-methylcoumarin groups via hexyloxy spacer, respectively, have been synthesized and characterized. Their optical properties were investigated with absorption and photoluminescence (PL) spectral methods. The emissions of COUPPV and model HOPPV films are similar and show peaks around 543–550 nm which is attributed to PPV backbone. Accordingly, efficient energy transfer from the 4-methylcoumarin chromophores to PPV backbone occurred readily in COUPPV. The highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) energy levels have been estimated from their cyclic voltammograms. As compared with HOPPV (LUMO: −2.86 eV), the electron affinity of COUPPV (LUMO: −3.65 eV) was enhanced greatly by introducing 4-methylcoumarin groups. Double-layer EL devices (Al/PEDOT/ COUPPV or HOPPV/ITO) revealed green electroluminescence. The photo-crosslinking behaviors of COUPPV film under ultraviolet irradiation were investigated by FT-IR and PL methods. Both C C of PPV and 4-methylcoumarin dimerized to cyclobutane derivatives and lead to crosslinking of the polymers. However, COUPPV exhibited higher photo-crosslinking rate due to pendant 4-methylcoumarin chromophores. Patterned emission from PLED utilizing this effect was also demonstrated.

Synthesis and properties of new luminescent poly(arylenevinylene) copolymers containing spirobifluorene

Two new light-emitting polymers, poly[2,2′-spirobifluorylene vinylene-alt-2,5-di-( n-buthoxy)-1,4-phenylene vinylene] (PSBF-PV) and poly[2,2′-spirobifluorylene vinylene-alt-9,9′-di-(fl-hexyl)-2,7-fluorenyl vinylene] (PSBF-FV) have been synthesized through the well-known Homer-Emons condensation between appropriate diphosphonates and dialdehydes. The polymers consist of arylenevinylene chromophores linked through 9,9′-spirobifiiorene to control the effective conjugation length and to suppress interchain aggregation. Photoluminescence maxima of PSBF-PV and PSBF-FV in thin solid film were shown at 512 and 446 nm, corresponding to green and blue-green emission, respectively. The single-layer light-emitting diodes of the two copolymers were fabricated in the configuration of ITO (indium-tin oxide)/polymer/Al, exhibiting weak emission. Better performance (luminance maxima is 846 cd/m 2) was achieved using Alq 3 as electron injection layer in double layer LEDs for PSBF-PV.

Synthesis and photophysics of new highly luminescent poly(alkylthiophene) derivatives with pyridine in the backbone

Starting from 2,6-bis-(3-octylthiophene-2yl)-pyridine, two new poly(alkylthiophene) derivatives, POTPyOT and POTPy, containing pyridine in the backbone were prepared from nickel(0)-mediated Stille coupling or by palladium-catalyzed Yamamoto coupling. These polymers exhibited good solubility in common organic solvents, thermal stability up to 400°C, and facile film formation. They were amorphous and give strong luminescence both in CHCl3 solution and solid state film. The polymers emitted blue light in solution with photoluminescence (PL) emission maximum at 420–484nm and green light with PL emission maximum at 500–514nm in thin films. These polymers showed a reversible redox reaction at potential from 0 to 1.3V (vs. SCE). Nevertheless, the reduced form of the polymer was very unstable; it decomposed in the presence of oxygen or water. The emission and UV–vis absorption of the polymer were influenced by the solvent polarity, protonation, and acid–base treatment. These may be the results of the stabilization of the polar excited state by solvation and the change of the conformation in polymer backbone. Electroluminescence (EL) was achieved from a single-layer PLED with the configuration of ITO/POTPyOT/Al. The turn-on voltage of the device is 10V and the λmax (550nm) of the EL is voltage independent.

Synthesis of soluble poly(9,10-dihydrophenanthrene-2,7-diyl)s. A new class of luminescent poly( p-phenylene)s with ethylene type bridges

Poly(9,10-dihydrophenanthrene-2,7-diyl)s with –OSi(R) 2(R′) groups at the 9,10-positions were synthesized by dehalogenative polycondensation of the corresponding monomers by using a zerovalent nickel complex. They showed number average molecular weights ( M n's) of 9800–69,000 and high quantum yields (62%-quantitative) in photoluminescence. Palladium catalyzed copolymerization of 2,7-dibromo-9,10-dihydrophenanthrene having –OCH 3 or –OSi(R) 2(R′) groups at the 9,10-positions with diethynyl- or diboronic-aromatic compounds also gave photoluminescent polymers with high quantum yields.

Luminescent poly(phenylene vinylene) derivatives with m‐terphenyl or 2,6‐diphenylpyridine kinked segments along the main chain: Synthesis, characterization, and stimulated emission

AbstractTwo new poly(phenylene vinylene)s containing m‐terphenyl or 2,6‐diphenylpyridine kinked units along the main chain were synthesized and were used as luminescent and laser materials. They were prepared from Heck coupling of 2,5‐didodecyloxy‐1,4‐divinylbenzene with 4,4″‐dibromo‐3′‐phenyl‐m‐terphenyl or 2,6‐di(4‐bromophenyl)‐4‐phenylpyridine. The kinked units along the main chain caused a partial interruption of the conjugation leading to emission at a shorter wavelength as compared with poly(p‐phenylene vinylene). The polymers presented blue‐green emission in solution and green‐yellow emission in the solid state with photoluminescence maxima at 465–497 and 546–550 nm, respectively. Polymer containing 2,6‐diphenylpyridine segments emitted at a longer wavelength than that containing m‐terphenyl and displayed higher quantum yields in solution (0.61 and 0.40, respectively). The influence of the solvent and polymer concentration on the photoluminescence characteristics was investigated. The photoluminescence properties of protonated polymer containing 2,6‐diphenylpyridine segments were investigated both in solution and in film. Amplified spontaneous emission and tunable laser action were also obtained from the two polymers. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 2214–2224, 2004

FABRICATIONS OF LUMINESCENT POLYMERIC NANOPARTICLES CONTAINING LANTHANIDE (III) ION COMPLEXES

Luminescent poly(ethylene glycol)-coated polystyrene (PSt) nanometer-sized particles (nanoparticles) containing trivalent europium or terbium ion were prepared by free-radical dispersion copolymerization of styrene, poly(ethylene glycol) (PEG) macromonomer, and the lanthanide complex which was coordinated with 1,10-phenanthroline possessing acryl group. Red and green luminescences with narrow band width were observed from each nanoparticle containing europium and terbium complexes, respectively.

Synthesis and properties of alkyl‐substituted poly(1,4‐phenylenevinylene) derivatives

AbstractThe luminescent poly(2‐dodecyl‐5‐methyl‐1,4‐phenylenevinylene) was synthesized with a new synthetic route. The structure and properties of the polymers were characterized by IR, UV‐vis, luminescent spectra, GPC, and both thermal and elemental analysis. The glass‐transition temperature increases and the photoluminescent relative quantum yield decreases with the increase of the conjugation extent of the polymer. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 1299–1304, 2001

Exciton dynamics in disubstituted polyacetylenes

Exciton dynamics in luminescent poly(diphenylacetylene) (PDPA) derivatives with different substituents have been studied by time-resolved photoluminescence (PL) spectroscopy. Although their absorption and PL spectra are almost similar, PL of PDPA-nBu decays single-exponentially, whereas PL of PDPA-SiMe 3 decays faster with a suppressed exponential decay function indicating exciton dissociation, In the case of PDPA-nBu mixed with a non-luminescent polyphenylacetylene (PPA) derivative, PL decay of PDPA-nBu is significantly shortened. The experimental results show the influences of side chains on exciton confinement in the backbone/main chain. Efficient PL in PDPA-nBu is a result of effective exciton confinement on the main chain, but excitons migration or energy transfer to another main chain segments may take places.

Studies of a poly(phenylenevinylene) without C2h symmetry

We have investigated the photophysics of the luminescent polymer poly(1,3-phenylenevinylene-alt-2,5-dioctyloxy-1,4-phenylenevinylene) (1,3-PPV) by a variety of optical spectroscopies. The incorporation of alternating meta-phenylene and para-phenylene rings reduces the conjugation length with respect to poly(para-phenylene vinylene) derivatives. As a consequence, excited states are blue-shifted and the nonlinear susceptibility is reduced. The reduced symmetry of 1,3-PPV modifies optical selection rules, resulting in strong overlap of the fluorescence spectrum with excited state absorption by charged polarons.

Synthesis and optical characterization of new highly luminescent poly(m,p-phenylenevinylene) derivatives

Poly(phenylenevinylene) (PPV) derivatives consisting of alternating m-phenylenevinylene and p-phenylenevinylene units were synthesized using the Wittig and the Wittig-Horner reactions. P1 which was prepared by the Wittig method contained both cis and trans double bonds in significant amounts. P2 was prepared by the Wittig-Horner reaction. Its vinylene configuration was nearly exclusively trans (>95%). The m-linkages reduced the π-conjugation length in an effective way leading to blueshifted UV-Vis absorption and PL emission spectra compared to analogous previously described PPV derivatives without m-phenylenevinylene units. A dependence of solubility, film forming properties, molecular weight and optical spectra on the amount of substituents per repeating unit was observed. A LED fabricated from P2 exhibited low threshold voltages for the electroluminescence (4,3V) and high luminance (1000 cd/m 2 at 10V).