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1.
Takakazu Yamamoto 《Journal of polymer science. Part A, Polymer chemistry》1996,34(6):997-1001
The ease of reduction of π-conjugated poly(p-phenylene)-, poly(naphthalene-2,6-diyl)-, and poly(naphthalene-1,4-diyl)-type polymers is determined by the electron accepting properties of the recurring aromatic units. Linear relationships hold between reduction potentials (Ered) of the π-conjugated poly(arylene)s and electron affinities (EA) of the recurring arylene units: Ered = ρEA + a. A ρ value of 0.85 ± 0.02 is found for the three types of polymers investigated. © 1996 John Wiley & Sons, Inc. 相似文献
2.
Novel and effective H-shaped chromophores were doped into polymethyl methacrylate (PMMA) to form guest-host polymer thin films.The measurement results of Maker fringe method show that the polymer thin films containing the H-shaped chromophores as a guest exhibit high second harmonic coefficients (d33) compared with other two-dimensional chromophores. 相似文献
3.
Shin‐ichiro Kato Koji Takagi Kirito Suzuki Takatoshi Kinoshita Yasuo Yuki 《Journal of polymer science. Part A, Polymer chemistry》2004,42(11):2631-2639
π‐Conjugated polymers (Poly1–Poly3) containing a 2,2′‐bipyridine (bpy) unit were subjected to coordination to nickel and copper dithiolate for the purpose of manipulating the photophysical properties. The absorption maximum peak of Poly1 [maximum wavelength (λmax) = 446 nm] redshifted by 36 nm upon the coordination of bpy to NiCl2, which produced Poly1–NiCl2. A further bathochromic shift was observed in the spectrum of Poly1–mntNi [mntNi = (maleonitrile dithiolate)nickel; λmax = 499 nm] bearing the dithiolate ligand, which stemmed from the extension of the conjugated system over the nickel dithiolate moiety through the bpy unit. An increase in the [Ni]/[bpy] ratio in Poly1–mntNi rendered the original maximum peak at 446 nm smaller and the lower energy charge‐transfer peak at 499 nm larger; the isosbestic points remained at 380 and 475 nm. The green fluorescence (λmax = 504 nm) emitted from Poly1 markedly diminished upon the coordination of nickel dithiolate because of the effective energy transfer. The absorption maximum peak of Poly1–mntNi in chloroform at 499 nm blueshifted to 471 nm when the volume ratio of the chloroform/N,N‐dimethylformamide solvent reached 10:90. The coordination of nickel dithiolate to Poly2 and Poly3 also brought about redshifts of the absorption maximum peaks of as much as 55 and 61 nm, respectively. The absorption maximum peak of Poly1–(phenyldithiolate)nickel(pdtNi) (λmax = 474 nm) redshifted by 28 nm in comparison with that of Poly1, whereas the magnitude of the shift of Poly1–bis(thiophenoxide)nickel(btpNi) bearing two thiophenoxide ligands was 20 nm. Poly1–mntCu with a tetrahedral copper center was also investigated. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 2631–2639, 2004 相似文献
4.
Quadratic nonlinear optical properties of ruthenium (II)-bipyridine complexes in crystalline powders
Quadratic nonlinear optical properties for the crystalline powders of two types of ruthenium-bipyridine [Ru(bipy)3] complexes were investigated. The nonlinear optical processes markedly depended on the molecular structures of the ruthenium complexes. Second harmonic generation (SHG) and very weak two-photon emission were observed for the alkylated ruthenium-bipyridine compexes with two long alkyl chains attached via amide bonds (RuCnB), whereas only two-photon emission was observed for Ru(bipy)3. The existence of two amide bonds in one bipyridine ligand for RuCnB complexes most probably enhanced the molecular hyperpolarizability as compared with Ru(bipy)3. The SHG intensity from RuCnB complexes increased in the order RuC18B < RuC12B < RuC16B. The order of SHG intensity from RuCnB was ascribed to the difference in size of each crystalline powder estimated by X-ray diffraction methods. 相似文献
5.
Shijie Ren Qiang Fang Feng Yu Dongsheng Bu 《Journal of polymer science. Part A, Polymer chemistry》2005,43(24):6554-6561
Two new π‐conjugated polymers containing 1,3,5‐triazine units in the main chain, Pa and Pb , are reported. Pa and Pb (R = H and ? OCH3, respectively) showed blue photoluminescence emissions with quantum yields of more than 50% in toluene. In the solid state, Pa and Pb showed photoluminescence maximum emission peaks at 479 and 475 nm, respectively. Electrochemically, Pa and Pb showed good stability and reversibility under repeated electrochemical reduction. The polymers had glass‐transition temperatures higher than 90 °C and had 5 wt % loss temperatures higher than 400 °C. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 6554–6561, 2005 相似文献
6.
A series of organosilicon polymers containing polysilane and diethynylaryl units along the polymer backbone were synthesized and examined with respect to their optical absorptions. The results indicate that delocalization takes place through the σ–π conjugated system. Lengthening of π-conjugation leads to lower excitation energies while nearly identical UV–vis spectra are observed with increased Si–Si chain length. Introducing a thiophene unit into the π-system instead of a benzene unit leads to a bathochromic shift reflecting greater σ–π delocalization. The polymers undergo photodegradation, probably via cleavage of the Si–Si bonds, and thermal crosslinking by reaction at the C≡C triple bonds. When doped with iodine, these polymers become semiconducting with conductivity of the order of 10?4 S cm?1. 相似文献
7.
Nonlinear optical susceptibility χ(3) of polydiacetylenes has been evaluated by third harmonic generation. First, in order to obtain the χ(3) tensor component along the polymer main chain, thin single crystals of two representative polydiacetylenes, poly-PTS and poly-DCHD were made by utilization of sampling technique in microscopy, i.e., the microtome cutting of single crystal embedded in plastic resin. The THG intensity observed was proportional to cos8θ, where θ was the angle between the polymer main chain and the polarization of laser light. The χ(3) value of poly-DCHD was found to be rather higher than that of poly-PTS. At resonant wavelength of 1.97 μm, the χ(3) of poly-DCHD attained 8 x 10?10 esu. Furthermore, it was confirmed that when geometrical correction were properly made, the χ(3) obtained from polycrystalline thin film of poly-PTS agreed well with that from thin single crystals. Secondary, regarding poly-diphenyldiacetylene derivatives, it was found that the π-conjugation between the polymer main chain and aromatic substituents was effective on the improvement of χ(3) values. The χ(3) magnitudes of poly-BTFP and poly-DFMP reflect well the dihedral angles between polymer main chain and the phenyl substituents (58° for poly-BTFP and 67° for poly-DFMP) as a measure of π-conjugation. Especially, at nonresonant region of 2.1 μm the χ(3) of poly-BTFP is about 5 times greater than that of poly-PTS. 相似文献
8.
Jongdeok An Jungyun Chang Jungwook Han Chan Im Young-Jun Yu Dong Hoon Choi Jung-Il Jin Tetsuro Majima 《Journal of photochemistry and photobiology. A, Chemistry》2008,200(2-3):371-376
Triplet energy level-dependent decay pathways of excitons populated on iridium (Ir) complexes within π-conjugated polymeric matrices were studied by means of photoluminescence (PL) and photoconduction action spectroscopy. We chose a set of matrices, poly(9-vinylcarbazole) (PVK), poly[9,9-bis(2-ethylhexyl)fluorene-2,7-diyl] (PF2/6), poly [2-(5′-cyano-5′-methyl-hexyloxy)-1,4-phenylene] (CNPPP), and poly [2-(5′-cyano-5′-methyl-hexyloxy)-1,4-phenylene-co-pridine] (CNPPP-py10 and CNPPP-Py20), having triplet energy levels ranging from 2.2 up to 3.0 eV. As Ir-complex dopants, we selected three phosphorescent emitters, iridium(III)bis(2-(2′-benzothienyl) pyridinato-N-acetylacetonate) (Ir(btp)2acac), iridium(III)fac-tris(2-phenylpyridine) (Ir(ppy)3), and iridium(III)bis[(4,6-fluorophenyl)-pyridinato-N,C2′]picolinate (FIrpic), having triplet energy levels of 2.1, 2.5, and 2.7 eV, respectively. It was found that the triplet emission from the dopants, being populated via energy transfer from the matrices, was strongly dependent on the matching of triplet energy levels between matrix polymers and Ir-complexes. Photocurrent action spectra confirm effective exciton confinement at the dopants sites in the case of PVK matrix systems. 相似文献
9.
Takakazu Yamamoto Yukiko Muramatsu Takahisa Shimizu Wataru Yamada 《Macromolecular rapid communications》1998,19(5):263-266
π-Conjugated polymers bearing nitro substituent(s), e.g., poly(aryleneethynylene) (PAE) type polymers and poly(4,8-dinitroanthraquinone-1,5-diyl) P(4,8-NO2-1,5-AQ), show semiconducting properties with electrical conductivities of an order of 10−7 to 10−6 S · cm−1 at room temperature without special oxidation and reduction of the polymer. P(4,8-NO2-1,5-AQ) shows a large shift of phase in alternating current (ac) measurements and a unique magnetism at low temperature. 相似文献
10.
Koichi Sakamaki Joji Ohshita Atsutaka Kunai Hidenobu Nakao Akira Adachi Koichi Okita 《应用有机金属化学》2001,15(12):939-946
We have synthesized novel σ–π conjugated polymers with N,N‐bis(p‐ethynylphenyl)‐N‐(p‐tolyl)amine as the π‐unit. The electroluminescent devices, with a double‐layer system composed of Alq and the present polymers as the emitting‐electron‐transporting and hole‐transporting layers respectively, emit green electroluminescence with a maximum intensity of 760 cd m?2. Copyright © 2001 John Wiley & Sons, Ltd. 相似文献
11.
The nonlinear optical property of new polyester has been studied via second harmonic generation (SHG). The values of electro‐optic coefficients, d33 and d31, of the poled polymer film were 3.15 × 10 ?7 and 1.5 × 10?7 esu, respectively. Thermal behavior of this polyester was studied through thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). 4‐di‐(2′‐hydroxyethoxy)‐4‐diphenyl‐hydrazonomethyl was synthesized from the reaction of 3,4‐dihydroxy‐4‐diphenyl‐hydrazonomethyl with 2–chloro–1‐ethanol in a 1:2 mole ratio and subsequently reacted with terephthaloyl chloride (TPC) in the presence of pyridine, as catalyst, to produce the new nonlinear polyester. The chemical structures of the resulting monomers and polymer were characterized by CHN analysis, 1H‐NMR, FT‐IR, and UV–Vis spectroscopy. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
12.
Take‐Aki Koizumi Shinichirou Kato Takakazu Yamamoto 《Journal of polymer science. Part A, Polymer chemistry》2011,49(19):4204-4212
Alternating π‐conjugated copolymers of 1,8‐naphthyridine‐2,6‐diyl ( 1,8‐Nap ) with 9,9‐dioctylfluorene‐2,7‐diyl ( P(Flu‐Ph‐1,8‐Nap) ) and 2,5‐didodecyloxy‐1,4‐phenylene ( P(ROPh‐Ph‐1,8‐Nap) ) have been synthesized by Pd‐catalyzed organometallic polycondensation. The copolymers showed UV‐vis absorption peaks at around 390 nm in o‐dichlorobenzene. The polymers were photoluminescent both in o‐dichlorobenzene and in the solid state. In o‐dichlorobenzene, the emission peaks of P(Flu‐Ph‐1,8‐Nap) and P(ROPh‐Ph‐1.,8‐Nap) appeared at λEM = 440 and 471 nm, with quantum yields of 87% and 66%, respectively. Electrochemical data revealed that 1,8‐Nap behaved as a typical electron‐accepting unit. When P(Flu‐Ph‐1,8‐Nap) was treated with 10‐camphorsulfonic acid, the emission peak shifted to λEM = 598 nm. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011 相似文献
13.
Koichi Sakamaki Joji Ohshita Atsutaka Kunai Hidenobu Nakao Akira Adachi Koichi Okita 《应用有机金属化学》2001,15(7):604-612
We have synthesized novel σ–π conjugated polymers with an alternating organosilanylene and π‐electron system, intending to utilize them for hole‐transporting materials of electroluminescent (EL) devices. 3,6‐Di(lithioethynyl)carbazoles were co‐polymerized with organodichlorosilanes to give the corresponding polymers with molecular weights of MW = 2000–5000. Another type of polymer with a thienylene unit was also synthesized by the nickel‐catalyzed reaction of the di‐Grignard reagent of 1,2‐bis[2‐(5‐bromothienyl)]tetraethyldisilane with 3,6‐dibromocarbazole, the molecular weight being Mn = 3100. The EL devices with a double‐layer system composed of tris(8‐quinolinolato)aluminum(III) and the present polymers as the emitting‐electron‐transporting and hole‐transporting layers, respectively, emit green EL with a maximum intensity of the order of 103 cd m?2. Of these, the device with the thienylene–carbazole polymers exhibited the highest luminance of 1480 cd m?2. Copyright © 2001 John Wiley & Sons, Ltd. 相似文献
14.
Jonas
rtegren Philippe Busson Ulf W. Gedde Anders Hult Anders Eriksson Mikael Lindgren Per-Otto Arntzn David S. Hermann Per Rudquist Sven T. Lagerwall 《Macromolecular Symposia》1999,148(1):179-195
Highly oriented pyroelectric liquid-crystalline polymers were prepared by photopolymerization under the influence of a static electric field from binary mixtures of two acrylate monomers exhibiting chiral smectic C mesomorphism. Both monomers contained nitro groups to yield second order nonlinear optical properties (second harmonic generation) and one of the monomers had two functional groups to yield a crosslinked polymer. The room temperature second order nonlinear susceptibility of the polymers showed during the first two hours a 10 % decrease after which it remained constant during the next 48 days. At elevated temperatures there was a significant difference in the nonlinear optical properties over time between crosslinked and uncrosslinked polymers. The uncrosslinked polymer showed a pronounced loss of second order nonlinear optical activity with time at ≥38°C. The crosslinked polymer showed a much smaller and basically a temperature independent decrease rate in the second order nonlinear optical properties at all the ageing temperatures (23-130°C). Both the loss in mesogen order parameter, very evident for the uncrosslinked polymer, and conformational changes occurring within the mesogens (β mechanism), may account for the observations made. 相似文献
15.
Coordination of π-conjugated polymers to transition metals constructs a novel redox system due to interchangeable various oxidation states of the polymers, which permits transition metals to interact with each other through a π-conjugate chain. The redox characteristics were found to depend on the electronic interaction with metals and the doping. A combination of copper(II) or iron(III) chloride and polyanilines afforded the complex catalysts with the higher oxidation capability for dehydrogenative oxidation. A catalytic system was also realized in the transition-metal-induced oxidation reaction, in which π-conjugated polymers serve as redox-active ligands participating in the reversible redox cycle. The Wacker oxidation of terminal olefins proceeded catalytically in the presence of a catalytic amount of polyaniline or polypyrrole derivative under oxygen. 相似文献
16.
Garth A. Jones Angela Acocella Francesco Zerbetto 《Theoretical chemistry accounts》2007,118(1):99-106
An explicit electron dynamics approach has been used to calculate the nonlinear optical properties of C60 and its radical anion. An external perturbation, in the form of an oscillating electric field, induces the time-evolution
of the molecular wavefunction. The time-averaged instantaneous dipole moment of the systems gives the molecular response to
perturbations of varying field intensities and frequency of oscillation. The polarizabilities and the second-order hyperpolarizabilties
have been calculated and are in good qualitative agreement with experimentally available data. In line with previous theoretical
and experimental studies, the nonlinear effect is enhanced for the radical species.
Contribution to the Fernando Bernardi Memorial Issue. 相似文献
17.
18.
Homoconjugation in poly(phenylene methylene)s: A case study of non‐π‐conjugated polymers with unexpected fluorescent properties
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Andreas Braendle Aleksandr Perevedentsev Nathan J. Cheetham Paul N. Stavrinou Jörg A. Schachner Nadia C. Mösch‐Zanetti Markus Niederberger Walter R. Caseri 《Journal of Polymer Science.Polymer Physics》2017,55(9):707-720
Poly(phenylene methylene) (PPM) exhibits pronounced blue fluorescence in solutions as well as in the solid state despite its non‐π‐conjugated nature. Optical spectroscopy was used to explore the characteristics and the physical origin of its unexpected optical properties, namely absorption in the 350–450 nm and photoluminescence in the 400–600 nm spectral regions. It is shown that PPM possesses two discrete optically active species, and a relatively long photoluminescence lifetime (>8 ns) in the solid‐state. Given the evidence reported herein, π‐stacking and aggregation/crystallization, as well as the formation of anthracene‐related impurities, are excluded as the probable origins of the optical properties. Instead there is sufficient evidence that PPM supports homoconjugation, that is: π‐orbital overlap across adjacent repeat units enabled by particular chain conformation(s), which is confirmed by DFT calculations. Furthermore, poly(2‐methylphenylene methylene) and poly(2,4,6‐trimethylphenylene methylene) – two derivatives of PPM – were synthesized and found to exhibit comparable spectroscopic properties, confirming the generality of the findings reported for PPM. Cyclic voltammetry measurements revealed the HOMO–LUMO gap to be 3.2–3.3 eV for all three polymers. This study illustrates a new approach to the design of light‐emitting polymers possessing hitherto unknown optical properties. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2017 , 55, 707–720 相似文献
19.
Ryosuke Nomura Ryota Moriai Masaru Kudo Tohru Hoshino Jun‐ichi Watanabe Shigeaki Funyu Ken‐ich Ishitsuka Sentaro Okamoto 《Journal of polymer science. Part A, Polymer chemistry》2013,51(16):3412-3419
Novel skipped‐π polymers in which the π‐components are connected with 2‐substituted trimethylene tethering units exhibit bathochromically shifted, broadened ultraviolet absorption with a unique lower‐energy absorption band and a largely red‐shifted fluorescent emission. These results suggest that through‐space π–π interactions owing to a stair‐like stacking substructure in these polymers extend the π‐conjugation of the components in the ground and excited states. As the photophysical properties of the polymers observed both in a solution and in a dried film are similar to those of the J‐aggregates of π‐molecules, these polymers may be considered as pseudo J‐stacking (or J‐like‐stacking) polymers. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2013 , 51, 3412–3419 相似文献
20.
Jong Hak Kim Byoung Ryul Min Jongok Won Yong Soo Kang 《Journal of Polymer Science.Polymer Physics》2006,44(10):1434-1441
Polymer/silver‐ion π‐complex membranes consisting of poly(hexamethylenevinylene) (PHMV) and silver tetrafluoroborate exhibit unusually high separation performance for olefin/olefin and olefin/paraffin mixtures. The formation of π complexes between silver ions and unsaturated C?C bonds of PHMV has been confirmed with wide‐angle X‐ray scattering, differential scanning calorimetry, and X‐ray photoelectron spectroscopy. Fourier transform infrared and ultraviolet spectroscopy studies have revealed that silver ions make π complexes with olefins such as 1,3‐butadiene, propylene, and ethylene. Of these three olefins, 1,3‐butadiene has the highest binding affinity with silver ions in dissolved in PHMV, and this results in its higher solubility and permeance. Therefore, the π‐complex membranes exhibit unusually high separation performance for olefin/olefin and olefin/paraffin mixtures. © 2006 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 44: 1434–1441, 2006 相似文献