A new donor‐acceptor type polymeric material from a thiophene derivative and its electrochromic properties

A new electrochromic polymer, poly(2,3,5,8‐tetra(thiophen‐2‐yl)quinoxaline) (PTTQ), was synthesized electrochemically and its electrochromic properties were investigated. The polymer was characterized by Cyclic Voltammetry, Fourier Transform infrared spectroscopy, UV‐Vis‐NIR Spectroscopy, and colorimetry. Spectroelectrochemistry analysis demonstrated that the polymer can undergo both p‐ and true n‐type doping processes. The polymer, (PTTQ), has three accessible color states: an oxidized transmissive, a neutral light bluish‐green, and a reduced transmissive light gray. Switching ability of the polymer was evaluated by kinetic studies. The polymer revealed an excellent optical contrast of 98% in the NIR region. Outstanding optical contrast in the NIR region, high stability and fast switching times make this polymer an excellent candidate for NIR device applications. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 3723–3731, 2008     

A new soluble conducting polymer and its electrochromic devices

A new polythiophene derivative was synthesized by both chemical and electrochemical oxidative polymerization of 1‐(1‐phenylethyl)‐2,5‐di(2‐thienyl)‐1H‐pyrrole (PETPy). Of which the chemical method produces a polymer that is completely soluble in organic solvents. The structures of both the monomer and the soluble polymer were elucidated by nuclear magnetic resonance (¹H and ¹³C NMR) and Fourier transform infrared (FTIR) spectroscopy. The average molecular weight has been determined by gel permeation chromatography to be M_n = 3.29 × 10³ for the chemically synthesized polymer. Polymer of PETPy was synthesized via potentiostatic electrochemical polymerization in acetonitrile (AN)/NaClO₄/LiClO₄ (0.1 M) solvent–electrolyte couple. Characterizations of the resulting polymer were performed by cyclic voltammetry, FTIR, scanning electron microscopy, and UV–vis spectroscopy. Four‐probe technique was used to measure the conductivities of the samples. Moreover, the spectroelectrochemical and electrochromic properties of the polymer films were investigated. In addition, dual‐type polymer electrochromic devices based on P(PETPy) with poly(3,4‐ethylenedioxythiophene) were constructed. Spectroelectrochemistry, electrochromic switching, and open circuit stability of the devices were studied. They were found to have good switching times, reasonable contrasts, and optical memories. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 2215–2225, 2006     

Maximum contrast from an electrochromic material

A general procedure to calculate the maximum contrast from an electrochromic material is presented. The obtained results were tested by spectroelectrochemical studies of two different conducting polymer films: poly-3, 4-ethylenedioxy-thiophene (PEDOT) and poly-3,6-bis(2-(3,4-ethylenedioxy)thienyl)-N-methylcarbazole (PBEDOT-NMCz). The presented methodology constitutes a useful tool for the optimization of electrochromic devices.     

A new near‐infrared switchable electrochromic polymer and its device application

A new near‐infrared switchable electrochromic polymer containing carbazole pendant (poly‐SNSC), synthesized by electrochemical polymerization of 2,5‐bis‐dithienyl‐1H‐pyrrole (SNS) main chain, has been prepared. The electrochemical and optical properties of SNSC monomer and its polymer have been investigated. Because of having two different electro‐donor moieties; that is, carbazole and SNS, SNSC gave two separate electrochemical oxidation and also light brown color of the film in the neutral state turn into gray on oxidation. An electrochromic device, contructed in the sandwich configuration [indium tin oxide (ITO)‐coated glass/anodically coloring polymer (poly‐SNSC)//gel electrolyte//cathodically coloring polymer (PEDOT)/ITO‐coated glass] and exhibited a high coloration efficiency (1216 cm² C^–1), a very short response time (about 0.3 s), low driving voltage, and a high redox stability. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2010     

A new alkaloid and its artificial derivative with an indazole ring from Nigella glandulifera

A new compound, nigeglanine (1), and its new artificial derivative (1a), were isolated from the seeds of Nigella glandulifera, together with a known aporphine alkaloid, fuzitine (2). Their structures were established by spectral analysis, including two-dimensional (2D)-NMR spectroscopy. Nigeglanine (1) is the third natural product determined to contain an indazole nucleus.     

A Free‐standing electrochromic material of poly(5,7‐bis(2‐(3,4‐ethylenedioxy)thienyl)‐indole) and its application in electrochromic device

Free‐standing poly(5,7‐bis(2‐(3,4‐ethylenedioxy)thienyl)‐indole) (PETI) was electrochemically obtained from 5,7‐bis(2‐(3,4‐ethylenedioxy)thienyl)‐indole (ETI) prepared by Stille coupling reaction of 5,7‐dibromoindole and 3,4‐ethylenedioxythiophene. For comparison, poly(5,7‐bis(2‐thiophene)‐indole) was also electrosynthesized from 5,7‐bis(2‐thiophene)‐indole (BTI) which was prepared from the 5,7‐dibromoindole and thiophene. Characterizations of ETI and BTI were performed by cyclic voltammetry, scanning electron microscopy, ¹H NMR, and ¹³C NMR spectroscopy. Spectroelectrochemical studies showed PETI had better electrochromic properties and showed two different colors (brown and blue‐violet) under various potentials with better maximum contrast (ΔT%) and coloration efficiency (CE). An electrochromic device (ECD) based on PETI and poly(3,4‐ethylenedioxythiophene) (PEDOT) was also constructed and characterized. This ECD had fast response time, high CE, better optical memory, and long‐term stability. These results indicated that PETI had potential applications for ECD. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017 , 55, 2356–2364     

Cationic and anionic environments in LiTFSI-doped di-ureasils with application in solid-state electrochromic devices

Fourier Transform mid-infrared and Raman spectroscopies were used to investigate the cation/polymer, cation/urea bridge, cation/anion and hydrogen bonding interactions in poly(oxyethylene) (POE)/siloxane di-ureasil networks prepared by the sol–gel route and doped with lithium bis(trifluoromethanesulfonyl)imide (LiTFSI). Materials with compositions 200 ?n ? 5 (where n expresses the molar ratio OCH₂CH₂/Li⁺) were studied. The Li⁺ ions coordinate to the urea carbonyl oxygen atoms over the whole range of salt concentration considered. Bonding to the ether oxygen atoms of the POE chains occurs at n ? 40, although a significant fraction of the POE chains remain non-coordinated. In these high salt content samples, the cations interact with the anions forming contact ion pairs. “Free” ions are probably the main charge carriers at the room temperature conductivity maximum of these ormolytes.     

A new Co(II)-metalloviologen-based electrochromic material integrated in thin multilayer films

A metallosupramolecular coordination polyelectrolyte prepared by the reaction of cobalt(II) with a novel bisterpyridine ligand has been assembled as the active component in electrochromic films by sequential deposition using electrostatic layer-by-layer self-assembly.     

Molecular assembled crosslinked self-doped polyaniline nano-thin films in application of electrochromic devices

Crosslinked self-doping polyaniline (SPANI) nano-thin films were prepared by using the molecular assembly process coupled with the copolymerization of aniline (AN) with the self-doping monomers DABSA (2,5-diaminobenzenesulfonic acid). DABSA were also used as surfactants and the di-amino groups rendered as chain extension/crosslinked sites in the simultaneous copolymerization and molecular assembly process. TEM and SEM results indicated that the morphology changes from micelles to nano-films. This SPANI nano-film is promising for the application in electrochromic devices.     

Recent advances in multifunctional electrochromic energy storage devices and photoelectrochromic devices

Multifunctional devices integrated with electrochromism and energy storage or energy production functions are attractive because these devices can be used as an effective approach to address the energy crisis and environmental pollution in society today. In this review, we explain the operation principles of electrochromic energy storage devices including electrochromic supercapacitors, electrochromic batteries, and the photoelectrochromic devices. Furthermore, the material candidates and structure types of these multifunctional devices are discussed in detail. The major challenges of these devices along with a further outlook are highlighted at the end.     

A new pyrrolidine derivative and steroids from an algicolous Gibberella zeae strain

A new pyrrolidine derivative, 3-hydroxy-5-(hydroxymethyl)-4-(4'-hydroxyphenoxy)pyrrolidin-2-one (1), and eight known steroids, (22E,24R)-7beta,8beta-epoxy-3beta,5alpha,9alpha-trihydroxyergosta-22-en-6-one (2, a reassigned structure of (22E,24R)-5alpha,6alpha-epoxy-3beta,8beta,14alpha-trihydroxyergosta-22-en-7-one), (22E,24R)-3beta,5alpha,9alpha-trihydroxyergosta-7,22-dien-6-one (3), (22E,24R)-3beta,5alpha-dihydroxyergosta-7,22-dien-6-one (4), (22E,24R)-ergosta-7,22-dien-3beta/,5alpha,6beta-triol (5), (22E,24R)-ergosta-5,22-dien-3beta-ol (6), (22E,24R)-5alpha,8alpha-epidioxyergosta-6,22-dien-3beta-ol (7), (22E,24R)-5alpha,8alpha-epidioxyergosta-6,9(11),22-trien-3beta-ol (8), and (22E,24R)-1(10 --> 6)-abeo-ergosta-5,7,9,22-tetraen-3alpha-ol (9), were isolated from the cultures of Gibberella zeae, an endophytic fungus isolated from the marine green alga Codium fragile. Their structures and relative stereochemistry were elucidated by 1D, 2D NMR and mass spectroscopic techniques. Compound 1 showed cytotoxicity against A-549 and BEL-7402 cell lines.     

A new biphenyl derivative from an unidentified marine fungus E33

A new biphenyl derivative 3,5′-dihydroxy-4′,5-dimethoxy-2′-methyl-[1,1′-biphenyl]-2-carboxylic acid methyl ester (1), was isolated from the culture broth of a fungus isolated from the rhizosphere soil of mangrove root on the South China Sea. The structure of 1 was determined by comprehensive spectroscopic methods, primarily 2D NMR techniques. Published in Khimiya Prirodnykh Soedinenii, No. 2, pp. 128–129, March–April, 2008.     

A new monoterpenoid indole alkaloid from Rauvolfia yunnanensis

One new monoterpenoid indole alkaloid, 11-methoxyburnamine-17-O-3′,4′,5′-trimethoxybenzoate (1), was isolated from Rauvolfia yunnanensis Tsiang. Its structure was identified by spectroscopic evidences.     

A new pyrone derivative from an endophytic Aspergillus tubingensis of Lycium ruthenicum

A new pyrone named 6-isovaleryl-4-methoxy-pyran-2-one (1), along with three known pyrone compounds, rubrofusarin B (2), asperpyrones A (3) and campyrone A (4), was isolated from fermentation of Aspergillus tubingensis in Lycium ruthenicum. Their structures were confirmed by spectroscopic techniques, such as IR, NMR and HRESI-MS. Compound 2 indicated strong inhibitory activity against Escherichia coli, with MIC value of 1.95 μg/mL.     

A new furan derivative from an endophytic Aspergillus flavus of Cephalotaxus fortunei

A new furan derivative named 5-acetoxymethylfuran-3-carboxylic acid (2), together with a known furan compound, 5-hydroxymethylfuran-3-carboxylic acid (1), were isolated from the fermentation of Aspergillus flavus, endophytic fungi in Cephalotaxus fortunei. The structures of 1 and 2 were elucidated by NMR, IR, UV and MS data, as well as compared with literature data. The compounds 1 and 2 exhibited potent antibacterial activity against Staphylococcus aureus with MIC values of 31.3 and 15.6 μg/mL, respectively. The compound 2 showed moderate antioxidant activity.     

A new 9-methoxyyohimbine-type indole alkaloid from Mitragyna africanus

A new yohimbine-type indole alkaloid (1). was isolated from the stem bark of Mitragyna africanus (WILLD.) collected in Nigeria, along with known seven Corynanthe-type oxindole alkaloids, two secoiridoids, three lignans, and a quinovic acid derivative. Their structures were elucidated by spectroscopic analyses.     

A new bibenzyl derivative from Pleione bulbocodioides

A new bibenzyl derivative 1,named 2-(4"-hydroxybenzyl)-3-(3'-hydroxyphenethyl)-5-methoxy-cyclohexa-2,5-diene-1,4- dione,and two known stilbenoids(2,3)were isolated from the tubers of Pleione bulbocodioides(Franch.)Rolfe.Their structures were elucidated by spectroscopic methods.     

A new pyrrolidone derivative from Pistacia chinensis

A new N-phenyl-pyrrolidone derivative had been isolated from Pistacia chinesis Bunge. Its structure was elucidated as 4-hydroxy-5-（2-oxo-1-pyrrolidinyl）-benzoic acid, named pistaciamide on the basis of the 1D-NMR, DEPT, HMQC and HMBC spectroscopic techniques. 2007 Xi Kui Liu. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.