Regioregular poly[3‐(4‐alkoxyphenyl)thiophene]s

An easy synthetic procedure for soluble poly[3‐(4‐alcoxyphenyl)thiophene]s is reported. The polymers present a high regioregularity degree as determined by both UV–vis spectra and ¹H and ¹³C NMR analysis. Furthermore, X‐ray powder diffraction analysis performed on films of the polymers suggests a π‐stacked packing structure of the macromolecules. Electrical characterization was performed on one of the synthesized polythiophenes on both undoped and doped (with FeCl₃ or iodine) films. The conductivity and charge‐carrier mobility were assessed by current–voltage and field effect measurements. Well‐structured polymer films were obtained simply via spin coating from chloroform solutions and without the need of further processing, unlike other regioregular polythiophenes reported in the literature. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 1758–1770, 2007     

Synthesis and characterization of polymethacrylates containing conjugated oligo(phenylene ethynylene)s as side chains

In order to form suitable systems designed for resonance energy transfer, a series of monodisperse methacrylate‐based monomers containing rigid π‐conjugated oligo(phenylene ethynylenes) with different sizes of the conjugated systems ( M1 – M3 ), and therefore different optoelectronic properties, were synthesized and subsequently polymerized using the reversible addition–fragmentation chain transfer polymerization technique ( P1 – P3 ). In addition, these oligomers were also copolymerized with methyl methacrylate. The obtained polymers were characterized by ¹H NMR spectroscopy, size exclusion chromatography, and analytical ultracentrifugation. The photophysical properties of the polymers were studied by UV–vis absorption and emission spectroscopy in diluted solutions as well as in thin films and compared to the photophysics of the corresponding monomers. Thereby, changes going from monomeric to polymeric systems could be detected in fluorescence quantum yields and lifetimes pointing to energy trapping, e.g., energy transfer. Donor–acceptor copolymers containing different numbers of monomeric units within the side chain exhibit differences in the emission spectra, indicating that energy trapping in polymers is very sensitive to structural properties such as the chain length. UV–vis absorption spectroscopy as well as time‐resolved lifetime studies indicate intrapolymer and interpolymer energy transfer. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012     

Synthesis, structure, and photophysical and electrochemical properties of a pi-stacked polymer

Dibenzofulvene (DBF) was polymerized using anionic initiators to afford a vinyl polymer. Oligo(DBF)s having from two to eight side-chain fluorene moieties bearing different chain-terminal groups were isolated by preparative size-exclusion chromatography. The structures of the isolated oligomers were revealed by single-crystal X-ray and (1)H NMR analyses. Both in solution and in crystal, the in-chain fluorene moieties stacked on top of each other, while the terminal conformation varied depending on the terminal group. These conformational characteristics were supported by molecular mechanics and dynamics calculations. The oligomers and polymers indicated hypochromism and red shift in UV absorption spectra and exclusive excimer emission in fluorescence spectra. In addition, reduced oxidation potentials were observed for the oligomers in electrochemical analyses, which suggests charge delocalization over the pi-stacked electron systems. The photophysical and electrochemical effects increased with the chain length of the oligomers and leveled off around the chain length of an oligomer consisting of five fluorene units.     

On the electronic structures and spectroscopic properties of polyyne and its derivatives

We present a theoretical study on the electronic structure and spectroscopic properties of polyyne and its derivatives using periodic density functional theory study and semiempirical ZINDO/s methods. The electronic density of states were calculated, which indicates that polyyne behaves like a semiconductor and the insertion of aromatic groups into the polymer chain gives rise to significant metallic characters in the materials. The vibrational and UV–vis spectra of polyyne and its derivatives were simulated using a monomer or oligomer model. The effects of aromatic insertion into polyyne chain on their electronic and spectroscopic properties were discussed. © 2008 Wiley Periodicals, Inc. Int J Quantum Chem, 2008     

Thermotropic liquid‐crystalline polymers having five‐membered heterocycles as mesogens, 6. Synthesis,thermotropic liquid‐crystalline and photoluminescent properties of novel semi‐rigid polyesters based on a terphenyl analogue of 1,3,4‐thiadiazole

Novel semi‐rigid thermotropic liquid‐crystalline (LC) polyesters containing terphenyl analogue of 1,3,4‐thiadiazole in the main chain were synthesized by melt polycondensation of a dioxydiundecanol derivative of 2,5‐diphenyl‐1,3,4‐thiadiazole with four aromatic diesters, and their structures were confirmed from FTIR, ¹³C NMR spectra and elemental analyses. Differential scanning calorimetry (DSC) measurements and polarizing microscope observations of textures showed that all the polymers form enantiotropic LC (smectic) phases. UV‐vis and photoluminescence (PL) spectra indicated that polyesters without nitro groups display maximum absorbances arising from 1,3,4‐thiadiazole moiety and blue‐emission maxima, the Stokes shifts being 69.5–79 nm in solution and 54–97 nm in the solid state.     

Blue emitting side-chain pendant 4-hydroxy-1,3-thiazoles in polystyrenes synthesized by RAFT polymerization

Blue emitting dyes bearing a luciferin analogous chromophore were attached to a polystyrene backbone. For this purpose, 4-hydroxy-1,3-thiazoles were functionalized with a styrene unit and polymerized using the reversible addition–fragmentation chain transfer (RAFT) polymerization technique. Two different chain transfer agents were investigated and one monomer was studied in terms of its kinetic behavior. The polymerization kinetics are presented and discussed in detail, showing a controlled polymerization behavior, resulting in well-defined copolymers with polydispersity indices below 1.2. The obtained polymers were characterized by size exclusion chromatography (SEC), ¹H NMR, MALDI-TOF MS and UV–vis absorption and fluorescence spectroscopy. In addition, the UV–vis absorption and emission behavior was investigated in thin films.     

Synthesis and spectroscopic studies of some new ortho functionalized triazene compounds and their reactivity with mercury (II) ion

In this work, a series of triazene derivatives in which the substituents have a wide range of electronic characters were synthesized to understand the effect of the substituent identity in controlling the changes in their electronic absorption spectra and NMR chemical shifts, as well as their tendency for interaction with some heavy metals. Elemental analysis and ¹H NMR, ¹³C NMR, and FT-IR spectroscopies were used to elucidate the chemical structures of the new compounds. Thermal analysis and protolysis of these triazenes were evaluated. The thermodynamic parameters were calculated from thermal data using Coats-Redfern method. Complexation of these compounds with mercury (II) ion in acetonitrile and deuterated dimethylsulfoxide (DMSO-d₆) solution were studied by UV–vis and ¹H NMR spectroscopy, respectively. Stoichiometry and formation constants of the complexes were calculated by the mole ratio titration method. The effects of the nature of the substituents on the formation constants were discussed.     

Synthesis and characterization of novel π‐conjugated polymers with phosphole ring derivatives

Novel π‐conjugated polymers ( 8 – 10 ) were prepared by the palladium‐catalyzed Sonogashira coupling reaction of three kinds of phosphole‐ring‐containing monomers with 2,5‐dihexyloxyl‐1,4‐diethynylbenzene. The obtained polymers ( 8 – 10 ) were regioregulated with the 2,5‐substituted phosphole ring in the polymer main chain and characterized with ¹H, ¹³C, and ³¹P NMR and FTIR. Polymers 8 – 10 were found to have an extended π‐conjugated system according to the results of UV–vis absorption spectra. In the fluorescence emission spectra of 8 – 10 , moderate emission peaks were observed in the visible blue‐to‐green region. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 2867–2875, 2007     

Photocrosslinking of thin films of temperature‐sensitive polymers

The use of polymeric materials with temperature‐dependent degrees of swelling (especially polymers that exhibit lower critical solution temperature (LCST) behaviour in aqueous solutions) in microsystems requires the preparation and patterning of layers in the µm range. Copolymers based on N‐isopropylacrylamide were modi‐fied with a stilbazolium salt chromophore to yield photocrosslinkable temperature‐sensitive polymers. The chromophore and the polymers were characterized by UV, IR, 1H‐NMR (nuclear magnetic resonance) and 13C‐NMR spectra. The resulting polymers showed LCST behaviour, which was measured by differential scanning calorimetry. The photocrosslinking properties were studied by UV irradiation of the thin films and measurement of the changes in the UV absorption spectra. By irradiation of thin films through a mask it was possible to obtain patterned networks in the µm range (20 µm space width and ≥50 µm line width). The resulting patterned networks showed temperature‐dependent swelling properties in aqueous media. Copyright © 1999 John Wiley & Sons, Ltd.     

Construction of diads and triads copolymer systems containing perylene,porphyrin, and/or fullerene blocks

A series of conjugated copolymers containing perylene, porphyrin, and/or fullerene units on the main chain have been synthesized. The structures and photophysical properties of polymers were characterized by FTIR, NMR, UV–vis, and fluorescence spectroscopy, gel permeation chromatography, and cyclic voltammetry. The photoinduced charge transfer properties of the films were also measured by a three‐electrode cell technique. A rapid, steady, and reproducible cathodic photocurrent response for each polymer was produced when the film was irradiated by a white light. The SEM and TEM images displayed the aggregation superstructures of the polymers. In chloroform, polySPeZnP₂F could form a large quantity of spherical nanoparticles. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 5863–5874, 2006     

α，α'-顺式二取代环十二酮的构象

利用分子力学计算，1~H NMR，(13)~C NMR和单晶X射线衍射分析技术研究了α -α'-顺式二表明，它们的优势构象骨架仍是[333]-2-酮，在晶体和溶液中，它们 的优势构象均为。α-角顺，α'-边外构象．在溶液中，相同取代基的α，α'-顺 式二取代环十二酮存在两种互为镜象的[3333]-2-酮对映体构象，学平衡之中；不 同取代基的α，α'-顺式二取代环十二酮存在体积较大的基团为边外取代的[3333] -2-酮和角顺取代的[3333]-2-酮两种构象，两种构象也处于动力学平衡之中，以较 大基团为边外取代的[3333]-2酮构象占优势.     

Synthesis,characterization, and electroluminescence of fluorene and carbazole‐based blue light‐emitting polymers with different noncoplanar molecular architectures

In order to investigate the explicit optoelectronic variations of the photoluminescent polymer with sterically hindered side chains, three novel alternate polymers (P0, P1, and P2) based on fluorene and carbazole moieties were successfully synthesized through Suzuki coupling reaction. The molecular structures of the polymers were fully characterized by ¹H‐NMR, ¹³C‐NMR, elemental analysis, and gel permeation chromatograph, respectively. The photophysical properties, thermal stability, and energy band gaps of polymers P0, P1, and P2 were further examined through UV–vis absorption, photoluminescent spectra, differential scanning calorimetry, thermogravimetric analysis, and cyclic voltammetry. The experimental results indicated that the polymers took on wide band gaps of about 3.50 eV with deep blue emission in thin solid films. These polymers were found to show a high thermal stability with decomposition temperatures at 5% weight loss of the compounds in the range of 353–416 °C. Blue light‐emitting electroluminescent devices of the most branched polymer P2 with highest light‐emitting efficiency as emitting layers were characterized, which showed obviously improved spectral stabilities with respect to the parent polyfluorene materials. In conclusion, we have established an effective method to improve the spectral stabilities of polyfluorene material by synthesizing the zigzag‐shaped copolymer of fluorene and carbazole with sterically hindered pendant moieties of different molecular sizes. Copyright © 2014 John Wiley & Sons, Ltd.     

Highly near‐infrared photoluminescence from aza‐borondipyrromethene‐based conjugated polymers

Near‐infrared (NIR) emissive conjugated polymers were prepared by palladium‐catalyzed Sonogashira polymerization of diiodobenzene‐functionalized aza‐borondipyrromethene (Aza‐BODIPY) monomers, which were substituted at 3 and 5 or 1 and 7 positions on the Aza‐BODIPY core, with 1,4‐diethynyl‐2,5‐dihexadecyloxybenzene or 3,3′‐didodecyl‐2,2′‐diethynyl‐5,5′‐bithiophene. The structures of the polymers were confirmed by ¹H NMR, ¹³C NMR, ¹¹B NMR, Fourier transform infrared (FT‐IR) spectroscopies, and size exclusion chromatography (SEC). The optical properties were then characterized by UV–vis absorption and photoluminescence (PL) spectroscopies, and theoretical calculation using density‐functional theory (DFT) method. The polymers were fusible and soluble in common organic solvents including tetrahydrofuran (THF), o‐xylene, toluene, CHCl₃, and CH₂Cl₂, etc. The UV–vis absorption and PL spectra of the polymers shifted to long wavelength region in comparison with simple Aza‐BODIPY as the counterpart because of extended π‐conjugation of the polymers. The polymers efficiently emitted NIR light with narrow emission bands at 713～777 nm on excitation at each absorption maximum. Especially, the polymer attached 1,4‐diethynyl‐2,5‐dihexadecyloxybenzene to 3,5‐position on the core revealed intense quantum yields (?_F = 24%) in this NIR region (753 nm). © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2010     

Synthesis,optical properties,and spectral stability of chiral dendronized binaphthyl‐containing polyfluorene derivatives

A new kind of chiral dendronized binaphthyl‐containing random polyfluorene derivatives bearing different contents (3.2–14.9 mol %) of Fréchet's polyether dendritic wedges have been designed and synthesized through a versatile Pd‐catalyzed Suzuki polycondensation. Their properties have been investigated by NMR, TGA, DSC, CD, UV–vis, and photoluminescence and compared to those of poly(9,9‐dihexylfluorene) ( PF ). It was found that attachment of Fréchet's dendritic wedges into the main chain enhanced the emission efficiency and thermal stability of the copolymers. Furthermore, different from PF , good to excellent spectral stabilities in the solid state were proven for all the dendronized chiral copolymers after a thermal annealing under air at 200 °C. The second‐generation dendronized polymer P3 bearing about 15 mol % of dendritic pendants exhibited high quantum yields in both solutions and films, and excellent thermal oxidative stability. These results demonstrated that the combination of the twisted nonplanar binaphthyl and the sterically demanding dendron could efficiently suppress the intermolecular packing and aggregation at much lower dendron contents compared to other reported dendronized polyfluorenes. Additionally, the investigation of circular dichroism spectra of these chiral dendronized polymers showed a strong Cotton effect at long wavelength (378–384 nm), indicating that the chirality of binaphthyl unit was transferred to the whole polyfluorene backbone. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 886–896, 2008     

染料掺杂有机改性硅酸盐的制备与光谱特性

1988年Pavlopoulos等人发现1,3,5,7-四甲基吡咯亚甲基BF₂化合物是一个性能优良的激光染料^[1].它的荧光量子效率高,激光效率比香豆素540A高10%,并具有低的三重态吸收和高的光化学稳定性.因此,在染料激光、生物荧光探针、光动力疗法等方面都有潜在的应用背景^[2~4].     

Preparation and Characterization of Six Bis(N-methylpyrrolidine)-C(60) Isomers: Magnetic Deshielding in Isomeric Bisadducts of C(60)

A series of isomers of bis(N-methylpyrrolidine)-C(60) 2 (Prato bisadducts) was prepared by the 1,3-dipolar cycloaddition of N-methylazomethine ylide to C(60). Six isomers were separated and characterized by ESI-MS, UV/vis, and (1)H and (13)C NMR spectroscopy. The structures of these bisadducts were assigned based on (1) comparison of their molecular symmetries with their (1)H and (13)C NMR spectra, (2) comparison of their UV/vis spectra with those of corresponding Bingel-Hirsch bisadducts, and (3) the order of deshielding of the methylene and N-methyl (1)H NMR resonances. Prato bisaddition is less chemoselective than Bingel-Hirsch bisaddition to C(60).     

Synthesis and characterization of water-soluble PEGylated lignin-based polymers by macromolecular azo coupling reaction

Water-soluble PEGylated lignin polymers were efficiently synthesized by macromolecular azo coupling reaction between alkali lignin and PEG based macromolecular diazonium salts in alkaline water.     

Synthesis, characterization and photochromic studies of three novel calix[4]arene-Schiff bases

Synthesis and characterization of three novel Schiff bases based on calix[4]arene are described. The synthesis of these compounds had been achieved by the condensation of salicylaldehyde derivatives with the amine group of upper rim of de-butylcalix[4]arene in ethanol. The structures of new compounds were confirmed on the basis of IR, (1)H NMR, (13)C NMR, MS and elementary analysis. Photochromic properties of compounds were studied in CH(3)CN by UV/vis and fluorescence spectra. These Schiff base-calix[4]arene can be used in certain 'supermolecular electronic devices' through combining the photochromic behaviors with others such as non-linear optical or charge transfer properties.     

Functional monomers and polymers. XCVII. Synthesis of oligomer models of polyethyleneimine derivatives containing pendant thymine bases

A series of oligomer models of polyethyleneimine derivatives having pendant thymine bases were prepared by the reaction of carboxyethyl derivatives of thymine with oligomer amines using an activated-ester method. It was found that the hypochromicity values obtained from UV spectra and pKa values obtained from spectrophotometric titrations depend on the chain length of the oligomers and the thymine content of the polymers.     

Unravelling the detailed microstructure of a semiconducting (quasi‐metal) soluble polymer incorporating conjugated thienylene methine sequences

This article reports a thorough spectroscopic characterization and the complete microstructural unravelling of a novel soluble poly(thienylene methylene) recently obtained by a straightforward process based on the methanesulfonic acid‐catalyzed self‐condensation of 2‐acetoxymethyl‐3,4‐dimethylthiophene. These macromolecules were found to generate both in situ (in the acidic reaction medium) and ex situ (by the addition of appropriate dopants) conjugated sequences consisting of alternating aromatic‐ and quinoid‐like thiophene rings, that is, conjugated thienylene methine sequences. The effect of different types of dopants on the electronic features of these polymers was assessed by the extent of bathochromic shifts they induced in the macromolecule UV–vis spectra. Doped films obtained by solution casting were characterized by dielectric spectroscopy to evaluate their electronic conductivity. The observed low values of conductivity were explained on microscopic basis evidencing the presence of polymer branching. All the structures arising from side reactions responsible for branching were determined by an exhaustive NMR study, which led to the formulation of the corresponding mechanisms. Remarkably, all these polymers, irrespective of their specific structural features and molecular weights, retained complete solubility in common solvents. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011