Discrete Photopatternable π-Conjugated Oligomers for Electrochromic Devices (original) (raw)
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Quaterthiophenes with Terminal Indeno[1,2- b ]thiophene Units as p -Type Organic Semiconductors
The Journal of Organic Chemistry, 2009
Quaterthiophenes 4T, Oct-4T, and Tol-4T based on a central 2,2′-bithiophene core R,ω-terminated with 4,4-unsubstituted and 4,4-disubstituted n-octyl or p-tolyl indeno[1,2-b]thiophene have been synthesized by Stille or Miyaura-Suzuki couplings. Compound 4T was also synthesized by an alternative route involving a soluble precursor bearing solubilizing trimethylsilyl groups which have been eliminated in the last step. The electronic properties of the compounds have been analyzed by cyclic voltammetry, UV-vis absorption and fluorescence emission spectroscopy. Thermal evaporation of 4T and Oct-4T leads to crystalline thin films and UV-vis absorption and X-ray diffraction data for these films suggest that the molecules adopt a quasi-vertical orientation onto the substrate. Strong π-π intermolecular interactions have been observed for 4T but not for molecules Oct-4T due to the presence of n-octyl chains. Sublimed thin films of Tol-4T show an amorphous character. The characterization of field-effect transistors fabricated from these three materials gave a hole-mobility of 2.2 × 10 -2 cm 2 V -1 s -1 with an on/off ratio of 2.2 × 10 4 for 4T while no field-effect was observed for Oct-4T and Tol-4T.
Organometallics, 2001
The palladium-catalyzed coupling (Stille coupling) of 2,5-diiodothiophene (1) with tributyl-(ethynyl)tin forms the 2,5-bis(ethynyl)thiophene (3) and tributyltin iodide as side product (step 1). Addition of lithium diisopropylamide (LDA) to this mixture causes deprotonation of the bis-alkyne and its reaction with the tin halide present in the medium to form the 2,5-bis[(tributyltin)ethynyl]thiophene (4) (step 2). To this mixture was subsequently added trans-dichlorobis(tri-n-butylphosphine)palladium (5), and the corresponding trans-bis(trin-butylphosphine)-µ- [2,5-bis(ethynyl)thiophene]palladium oligomer (6) was obtained (step 3). Alternatively, the same route can be directed toward the formation of ethynylated thiophene oligomers: after formation of the 2,5-bis[(tributyltin)ethynyl]thiophene (4) (step 2), addition of 2-iodothiophene (8) or 2-iodo-5-(trimethylsilyl)thiophene (10) led to the formation of 2,5-bis(2-thienylethynyl)thiophene (9) (step 3) and [2-trimethylsilyl(ethynyl)thiophene]-2,5-bisethynylthiophene (11) (step 3′), respectively. The latter can be easily desilylated to obtain the [2-(ethynyl)thiophene]-2,5-bisethynylthiophene (13), while treatment of 9 with sec-BuLi/I 2 formed the 2,5-[2,2′-(5,5′-diiodo)bisthienyl]bisethynylthiophene (12). Through a sequence of transformations similar to steps 1-3, the oligo(iodo)ethynylthiophene 12 has been connected to the bis(tri-n-butylphosphine)palladium moiety to form the transbis(tri-n-butylphosphine)-µ-[2,2′-bis(ethynyl)thiophene]-2,5-bisethynylthiophene]palladium polymer (15). To compare the advantages of the above extended one-pot (EOP) procedures over classical routes, polymers 6 and 15 were also prepared by the copper-catalyzed reaction of trans-dichlorobis(tri-n-butylphosphine)palladium (5) with 2,5-bis(ethynyl)thiophene and [2-(ethynyl)thiophene]-2,5-bisethynylthiophene (13). . (1) Takahashi, S.; Takai, Y.; Morimoto, H.; Sonogashira, K.; Hagihara, N. Mol. Cryst. Liq. Cryst. 1982, 32, 139. (2) (a) Posselt, D.; Badur, W.; Steiner, M.; Baumgarten, M. Synth. Met. 1993, 55-57, 3299. (b) Hmyene, M.; Yassar, A.; Escorne, M.; Percheron-Guegan, A.; Garnier, F.
Synthesis and Coordination Properties of Chelating Dithiophenolate Ligands
Inorganic Chemistry, 2009
Chelating 3,3′-R 1 -5,5′-R 2 -2,2′-dithiobiphenyl ligands (R 1 ) R 2 ) Cl, 4a; R 1 ) R 2 ) t Bu, 4b; R 1 ) allyl, R 2 ) H, 4c) and the 2,2′-methylenedibenzenethiol ligand (4d) were synthesized from the corresponding diols (1a-1d) via a three-step procedure involving a Miyazaki-Newman-Kwart rearrangement. Zinc complexes and a tin complex (for 4c) have been prepared to explore their coordination potential, and the substitution pattern, as well as the chelate ring size, is shown to severely effect their ligating properties. Four of the complexes have been characterized crystallographically in the solid state, and the nuclearity of the zinc complexes in solution has been studied by diffusion-ordered NMR spectroscopy. Depending on the ligand, zinc complexes [(4)Zn(4,4′-t Bu-bipyridine)] n (5a-d) are monomeric (n ) 1; 4b, 4c), monomeric in solution and dimeric in the solid state (n ) 1, 2; 4a), or dimeric overall (n ) 2; 4d). The tin complex (4c)SnPh 2 (6c) was additionally synthesized to prove the coordinating abilities of the allyl substituted ligand 4c.
Journal of The Electrochemical Society, 2015
Herein, we report the synthesis of two donor-acceptor-donor polymers (P1 and P2) based on thiophene (M1) and thieno [3,2-b]thiophene (M2) as the donor and 2,5-bis(dodecyloxy)benzene as the acceptor unit. The effects of different donor units on the polymers' electrochemical and optical properties were examined by cyclic voltammetry and spectroelectrochemical analysis. Introducing thieno[3,2-b]thiophene unit as the donor unit enhances π-stacking and consequently lowering the bandgap of the resulting polymer. The electronic band gaps, defined as the onset of the π-π * transition, were found to be 2.0 eV for P1 and 1.7 eV for P2. Both P1 and P2 films revealed multi-colored electrochromism. A dual-type complementary colored electrochromic device (ECD) using P2/PEDOT in sandwich configuration was constructed. Spectroelectrochemistry, switching ability and open circuit memory of the ECD were investigated. During the past decade, the field of organic electronics has progressed enormously as a result of growing interest in materials chemistry. The first generation of conducting organic materials were composed of predominantly carbon-based molecular structures such as linear acenes, poly acetylene, and poly(p-phenylene viny-lene) derivatives (PPV). 1-3 The following generation involved the widespread incorporation of heterocycles into the conjugated backbone such as thiophene, pyrrole and their derivatives. 4-6 Currently, conjugated polymers and small organic molecules have been designed using "donor-acceptor" strategy. 7-10 This method involves synthesizing monomers and polymers with a delocalized π-electron system that consists of alternating electron-rich (donor) and electron-deficient (acceptor) units. The combination of high-lying HOMO levels (residing on the donor units) and low-lying LUMO levels (residing on the acceptor units) results in a local electron density gradient along the backbone, creating a lower energy charge-transfer transition. 11,12 The presence of this lower energy transition leads to smaller optical band gaps. A low bandgap leads to absorption in the visible region. Low bandgap, stability, solubility (which is crucial for their processability), planarity (which is important for obtaining good π-orbital overlap and effective electron delocalization) are the main requirements for organic electronic materials. In an attempt to manipulate relevant parameters to fulfill these requirements through synthetic expertise, numerous organic heterocyclic and pendant groups have been incorporated into the backbones of donor-acceptor conjugated polymers and small molecules. Thiophene based materials have demonstrated great potential as donor units due to their desirable properties such as stability , ease of synthesis, and modification. In recent years, thiophene moiety was coupled with benzoselenadiazole, 13 benzotriazole, 14,15 carbazole, 16 benzothiadiazole, 17,18 ethylenedioxythiophene, 19 diketopyrrolopyrrole, 20 3-alkylthiophene, 21 quinoxaline, 22 and benzimidazole. 23 The study of the opto-electronic properties of conjugated polymers and small organic molecules designed based on D-A approach provides valuable information for understanding the structure-property relationship. And also it allows designing materials with an enhanced opto-electronic property. These materials have been used in organic light-emitting diodes, 24-27 organic solar cells, 28-31 field effect transistors, 32-34 sensors, 35-37 and electrochromic devices (ECDs). 38-43 Conjugated polymers have gained great attention for ECDs due to the z fact that they are more processable than inorganic electrochromic materials and offer the advantage of a high degree of color tailorability. Electrochromism is defined as the reversible change in transmittance and/ or reflectance of the material upon applied voltage. The color changes between a transparent state and a colored state or between the two colored states are associated with electrochemically induced oxidation-reduction reactions. In this paper, we report two new donor-acceptor-donor conjugated polymers which were synthesized by combining electron-accepting 2,5-bis(dodecyloxy)benzene with electron-donating thiophene and thieno[3,2-b]thiophene. The influence of the structural differences of the electron-donating units on the electrochemical and optical properties of the resulting polymers was investigated. Experimental General.-All reagents and chemicals were obtained from commercial sources and used without further purification unless otherwise mentioned. 1,4-Bis(dodecyloxy)benzene, 44 1,4-dibromo-2,5-bis(dodecyloxy)benzene, 44 tributyl(thiophen-2-yl)stannane, 45 tributyl(thieno[3,2-b]thiophen-2-yl)stannane 46 were synthesized according to previously published procedures. Tetrahydrofuran (THF) was dried over sodium and benzophenone. Bruker Spectrospin Avance DPX-400 Spectrometer was used to record 1 H NMR and 13 C NMR spectra of synthesized materials in CDCl 3. Chemical shifts were recorded in ppm downfield from tetramethylsilane. Elec-tropolymerization of monomers were achieved in a three-electrode electrochemical cell. Indium Tin Oxide doped glass slide (ITO) as the working electrode, platinum wire as the counter electrode, and Ag wire as the pseudo reference electrode were used under ambient conditions using a Gamry potentiostat. Spectroelectrochemical studies of polymers were performed on a Varian Cary 5000 UV-Vis-NIR spectrophotometer. Minolta CS-100 colorimeter was used to perform colorimetry studies. Synthesis.-1,4-bis(dodecyloxy)benzene (2).-To a solution of hy-droquinone (4.00 g, 36.3 mmol) in dry DMF (50.0 ml), K 2 CO 3 (20.8 g, 83.6 mmol) was added and the solution was stirred under inert atmosphere at 100 • C for 1 hour. Then 1-bromododecane (15.1 g, 109 mmol) was added to the mixture. After 42 hours, the mixture was cooled to room temperature and poured onto distilled water. The product was extracted with CH 2 Cl 2 , and dried over anhydrous MgSO 4. After) unless CC License in place (see abstract). ecsdl.org/site/terms_use address. 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Photolysis of some 3-alkoxy-2-thienylchromones
Arkivoc, 2007
Photo induced cyclisation of some 3-alkoxy-2-thienylchromones has been described. The photoreactions occur through intramolecular H-abstraction by the carbonyl group to provide 1,4biradical that yield dihydrocyclised and dehydrocyclised compounds. The total photolytic conversion and stereochemistry of the dihydrocyclised products are controlled by the nature of substituents present at the carbon undergoing photo H-abstraction.
3-Substituted thiophenes. XII. Bromination of β-3-thienylacrylic acid
Journal of Heterocyclic Chemistry, 1964
Bromination of p-Bthienylacrylic acid in glacial acetic acid gave P(2Lbrorno-3-thienyl)acrylic acid with an equivalent of bromine, and p-(2,5-dibromo-3-thienyl)-a, 0-dibromopropionic acid with excess bromine. In hot carbon tetrachloride, an excellent yield of the stable olefinic addition product, p-3-thienyl-a p-dibromopropionic acid, was obtained, and its structure was confirmed by conversion to p-bromo-3-thienylethylene in base. 3-Thenaldehyde underwent a Darzen's Glycidic Ester condensation to produce ethyl p-3thienyl-a ,p-epoxypropionate, but treatment of this ester or the salt of its derived acid with hydrogen bromide led to the formation of unstable products. The structure of the bromo-acids and derivatives were confirmed by unequivocal syntheses and/or by nuclear magnetic resonance spectra.
Chemical Communications, 2009
All chemicals and solvents were of reagent grade obtained from Aldrich, Arco, or TCI Chemical Co. Solvents (toluene, benzene, ether, THF, and hexanes) were distilled under nitrogen from Na/benzophenone ketyl, and halogenated solvents were distilled from CaH 2 . Compound 1 and 2 were prepared according to literature procedures. 1,2 1 H and 13 C NMR spectra were recorded on Bruker 500, 300, or Bruker DRX-200 instrument. Chemical shifts for 1 H and 13 C spectra were referenced to solvent peaks. 19 F NMR spectra were referenced to external CFCl 3 . DSC thermographs were carried out on a Mettler DSC 822 and calibrated with a pure indium sample with a scan rate of 10.0 °C/min. Thermogravimetric analysis (TGA) was performed with a Perkin Elmer TGA-7 thermal analysis system using dry nitrogen as a carrier gas at a flow rate of 40 ml/min. The UV-vis absorption and fluorescence spectra were obtained using a JASCO V-530 and a Hitachi F-4500 Supplementary Material (ESI) for Chemical Communications This journal is (c) The Royal Society of Chemistry 2009