3141-26-2Relevant articles and documents
New copolymers with thieno[3,2-b]thiophene or dithieno[3,2-b:2′,3′-d]thiophene units possessing electron-withdrawing 4-cyanophenyl groups: Synthesis and photophysical, electrochemical, and electroluminescent properties
Vyprachticky, Drahomír,Demirtas, Ilknur,Dzhabarov, Vagif,Pokorná, Veronika,Ertas, Erdal,Ozturk, Turan,Cimrová, Věra
, p. 2629 - 2638 (2017)
New monomers containing 4-cyanophenyl (–PhCN) groups attached to a thieno[3,2-b]thiophene (TT) or dithieno[3,2-b:2′,3′-d]thiophene (DTT) structure were synthesized and characterized as 4-(2,5-dibromothieno[3,2-b]thiophen-3-yl)benzonitrile (Br–TT–PhCN) or 4,4′-(2,6-dibromodithieno[3,2-b:2′,3′-d]thiophene-3,5-diyl)dibenzonitrile (Br–DTT–PhCN). The Suzuki coupling of 9,9-dioctylfluorene-2,7-diboronic acid bis(1,3-propanediol)ester and the Br–TT–PhCN or Br–DTT–PhCN monomer was utilized for the syntheses of novel copolymers poly{9,9-dioctylfluorene-2,7-diyl-alt-3-(4′-cyanophenyl)thieno[3,2-b]thiophene-2,5-diyl} (PFTT–PhCN) and poly{9,9-dioctylfluorene-2,7-diyl-alt-3,5-bis(4′-cyanophenyl)dithieno[3,2-b:2′,3′-d]thiophene-2,6-diyl} (PFDTT–PhCN), respectively. The photophysical, electrochemical, and electroluminescent (EL) properties of these novel copolymers were studied. Their photoluminescence (PL) exhibited the same emission maximum for both copolymers in solution. Red-shifted PL emissions were observed in the thin films. The PL emission maximum of PFTT–PhCN was more significantly redshifted than that of PFDTT–PhCN, indicating more pronounced excimer or aggregate formation in PFTT–PhCN. The ionization potential (HOMO level) and electron affinity (LUMO level) values were 5.54 and 2.81 eV, respectively, for PFTT–PhCN and were 5.57 and 2.92 eV, respectively, for PFDTT–PhCN. Polymer light-emitting diodes (LEDs) with copolymer active layers were fabricated and studied. Anomalous behavior and memory effects were observed from the current–voltage characteristics of the LEDs for both copolymers.
Robust PEDOT films by covalent bonding to substrates using in tandem sol-gel, surface initiated free-radical and redox polymerization
Sadekar, Anand G.,Mohite, Dhairyashil,Mulik, Sudhir,Chandrasekaran, Naveen,Sotiriou-Leventis, Chariklia,Leventis, Nicholas
, p. 100 - 108 (2012)
Poly(3,4-ethylenedioxythiophene), PEDOT, films are used as antistatic coatings on electrically insulating substrates such as plastic and glass. A novel method for the synthesis of conducting PEDOT films on insulators relies on sol-gel chemistry to attach a di-Si(OEt)3 functionalized free radical initiator (AIBN) on oxidized surfaces, followed by: (a) attachment of 3,4-(vinylenedioxy)thiophene (VDOT: an analogue to EDOT susceptible to radical addition through its vinylenedioxy group); and, (b) oxidative (with FeCl 3) co-polymerization of surface-confined VDOT with 3,4-ethylenedioxythiophene (EDOT). In conjunction with classical photolithography, the method yields thin (～150 nm) yet dense, pinhole-free (confirmed electrochemically), hard (>6H), extremely adhesive (5B), patterned, highly conducting (52 mho cm-1) films. The process is applied mainly on glass but it works equally well on oxidized metal surfaces (aluminum, steel, Pt). Control studies related to "grafting from" with surface-confined AIBN were conducted by growing inexpensive poly(styrene) and poly(methylmethacrylate) films.
Synthesis, electropolymerization and characterization of a cross-linked PEDOT derivative
Arias-Pardilla, Joaquin,Gimenez-Gomez, Pablo A.,De La Pena, Alejandro,Segura, Jose L.,Otero, Toribio F.
, p. 4944 - 4952 (2012)
The synthesis of a novel electropolymerizable monomer, 2,2′,3, 3′-tetrahydro-2,2′-bithieno[3,4-b][1,4]dioxine (THBTD), based on two 3,4-ethylenedioxythiophene (EDOT) moieties connected through the ethylenedioxy bridge is reported. The new monomer paves the way for the development of cross-linked networks based on the EDOT moiety. Polymer films were electrogenerated from monomeric solutions by consecutive potential sweeps or by flow of constant anodic currents and the polymer structure was studied using FTIR. The relationship between the mass of the electrogenerated polymer (after reduction) and the polymerization charge gives the productivity of the consumed charge (mg C-1) while the charge stored and delivered by the films was determined by cyclic voltammetry getting the specific charge (C g -1). Simultaneously with the electroinitiated polymerization a chemical polymerization occurs around the electrode by monomer protonation giving protonated and no electroactive polymer chains. This chemical polymerization was followed in solution by UV-Vis spectroscopy using different conditions. Productivities and specific charges change with the conditions of synthesis in opposite directions. The voltammetric control presents a main redox couple (0.54/0.50 V) and a strong reduction process at -2.89 V that only can be reoxidized at more anodic potentials than 0.3 V as usual for charge trapping effects. EQCM studies indicate a remarkable difference between PEDOT and poly(THBTD). While poly(THBTD) shows a predominantly reversible anionic exchange during oxidation from the neutral state, the parent pristine PEDOT presents a mixed anionic and cationic exchange. Electrochromic color changes from an intense blue color of the oxidized film to a clear orange color in the reduced films as observed by in situ UV-Vis spectroscopy. Interestingly, the electrochromic changes in poly(THBTD) are opposed to those of PEDOT. Both thiophene derivative polymers present a similar thermal degradation at 305 and 314 °C, respectively.
Synthesis and characterization of monomeric and polymeric Cu(II) complexes of 3,4-ethylenedioxythiophene-functionalized with cyclam ligand
Velauthamurty, Kuhamoorthy,Higgins, Simon J.,Rajapakse, R.M. Gamini,Bandara,Shimomura, Masaru
, p. 326 - 332 (2010)
A functionalized EDOT derivative with 1,4,8,11-tetraazacyclotetradecane (cyclam) ligand pendant to the ethylene bridge (4) and its complexes [M(4)(BF4)2], where M(II) = Cu(II), was prepared and characterized. Their electrochemical copolymerization with EDOT was studied. The electro-co-polymerized films were characterized by electrochemical methods, X-ray photoelectron spectroscopy and by X-ray fluorescence spectroscopy. The co-polymerization method was found to afford a good control of the metal concentration in the polymer matrix and represents a good technique for preparing electronically conductive polymers containing redox-active metal complexes.
On the origin of optical activity in polythiophenes
Langeveld-Voss,Janssen,Meijer
, p. 285 - 301 (2000)
Optically active substituents attached as sidechain to π-conjugated polymers provide a particularly interesting and revealing tool to study the nanoscopic and mesoscopic supramolecular organization of π-conjugated polymers in general. Chiral substituents allow the properties of these polymers to be studied with circularly polarized light in both absorption and emission. Here we describe a comprehensive investigation on the structure and optical properties of poly{3,4-bis[(S)-2-methylbutoxy]thiophene} (PBMBT) as an example to elucidate the molecular origin of the chiroptical effects in chiral conjugated polymers. The chiral side chains of PBMBT induce very strong bisignate circular dichroism (CD) effects in the π-π* absorption when the polymer is in an aggregated phase. The anisotropy factor in absorption (g(abs)) is as high as 8 x 10-2. The photoluminescence of PBMBT aggregates is characterized by a very small stokes shift (90 meV) and exhibits circular polarization (CPL). The chiroptical properties in absorption and emission of PBMBT are associated with a high degree of intrachain and interchain order as they are present in aggregated phases but absent when the polymer chains are molecularly dissolved or in a melt. The observed CD and CPL effects are consistent with an exciton splitting between transition dipole moments in the excited state on different polymer chains. The strong optical activity associated with the π-π* transition of PBMBT is attributed to originate from a helical packing of predominantly planar chains, rather than from a helical intrachain conformation. As a result a detailed molecular description of the polythiophene morphology is obtained. (C) 2000 Elsevier Science B.V.
Selective Debromination of Thiophene Derivatives by Electrochemical Reduction
Dapperheld, S.,Feldhues, M.,Litterer, H.,Sistig, F.,Wegener, P.
, p. 403 - 405 (1990)
The debromination of polybrominated derivatives is achieved by electrochemical reduction with good yields and high selectivity.
Elastic and inelastic electron tunneling spectroscopy of a new rectifying monolayer
Honciuc, Andrei,Metzger, Robert M.,Gong, Aijun,Spangler, Charles W.
, p. 8310 - 8319 (2007)
Rectification of electrical current was observed in a Langmuir-Schaefer monolayer of fullerene-bis[ethylthio-tetrakis(3,4-dibutyl-2-thiophene-5-ethenyl) -5-bromo-3,4-dibutyl-2-thiophene] malonate, Au electrodes at room temperature (there are two regimes of asymmetry, at lower bias, i.e., between 0 and ±2 V, and at higher bias), and also between Pb and Al electrodes at 4.2 K. The latter experiment was coupled with second harmonic detection of the second derivative of the current with respect to voltage (d2I/dV 2). The d2I/dV2 spectrum shows intramolecular vibrations, and also two antisymmetric broad bands, centered at ±0.65 V, due to resonant electron tunneling between the Fermi level(s) of the electrodes and the lowest unoccupied molecular orbital of the molecule.
Isomeric effect of fluorene-based fused-ring electron acceptors to achieve high-efficiency organic solar cells
Cao, Fong-Yi,Cheng, Yen-Ju,Huang, Po-Kai,Su, Yen-Chen,Xue, Yung-Jing
supporting information, p. 5315 - 5322 (2020/03/19)
Acceptor-donor-acceptor (A-D-A) non-fullerene electron acceptors (NFEAs) using ladder-type donor structures have become the dominant n-type materials for achieving high-efficiency OSCs. In this work, two isomeric fluorene-based ladder-type structures FCTT (TT-C-F-C-TT) and FTCT (T-C-TFT-C-T) have been designed and synthesized. These two isomeric donors with the different fused-ring arrangement, molecular geometry, and side-chain placement were end-capped with the FIC acceptors to form two NFEAs FCTT-FIC and FTCT-FIC isomeric materials. Compared to FTCT-FIC using the thiophene (T)-terminal donor, FCTT-FIC with the thienothiophene (TT)-terminal donor has more evenly distributed side chains on both sides of the backbone and less steric hindrance near the FIC acceptors, which enables stronger antiparallel π-π packing among the end-groups to create a channel for efficient electron transport, as evidenced by the thin-film GIWAXS measurements. FCTT-FIC displayed a larger optical bandgap and deeper-lying energy levels than its FTCT-FIC isomer. Compared to the PBDB-T:FTCT-FIC device, the PBDB-T:FCTT-FIC device showed a higher PCE of 10.32% with an enhanced Jsc of 19.63 mA cm-2 and an FF of 69.14%. A PM6:FCTT-FIC device using PM6 as a p-type polymer achieved the highest PCE of 12.23%. By introducing PC71BM as the second acceptor to enhance the absorption at shorter wavelengths, optimize the morphology and facilitate electron transport, the ternary-blend PM6:FCTT-FIC:PC71BM (1 : 1 : 0.5 in wt%) device yielded the highest PCE of 13.37% with a Voc of 0.92 V, a higher Jsc of 19.86 mA cm-2, and an FF of 73.2%. This result demonstrated that the TT-terminal ladder-type donor is generally a better molecular design than the corresponding T-terminal ladder-type isomer for the development of new A-D-A NFEAs.
From Red to Green Luminescence via Surface Functionalization. Effect of 2-(5-Mercaptothien-2-yl)-8-(thien-2-yl)-5-hexylthieno[3,4- c]pyrrole-4,6-dione Ligands on the Photoluminescence of Alloyed Ag-In-Zn-S Nanocrystals
Kowalik, Patrycja,Bujak, Piotr,Wróbel, Zbigniew,Penkala, Mateusz,Kotwica, Kamil,Maroń, Anna,Pron, Adam
supporting information, p. 14594 - 14604 (2020/10/09)
A semiconducting molecule containing a thiol anchor group, namely 2-(5-mercaptothien-2-yl)-8-(thien-2-yl)-5-hexylthieno[3,4-c]pyrrole-4,6-dione (abbreviated as D-A-D-SH), was designed, synthesized, and used as a ligand in nonstoichiometric quaternary nanocrystals of composition Ag1.0In3.1Zn1.0S4.0(S6.1) to give an inorganic/organic hybrid. Detailed NMR studies indicate that D-A-D-SH ligands are present in two coordination spheres in the organic part of the hybrid: (i) inner in which the ligand molecules form direct bonds with the nanocrystal surface and (ii) outer in which the ligand molecules do not form direct bonds with the inorganic core. Exchange of the initial ligands (stearic acid and 1-aminooctadecane) for D-A-D-SH induces a distinct change of the photoluminescence. Efficient red luminescence of nanocrystals capped with initial ligands (λmax = 720 nm, quantum yield = 67%) is totally quenched and green luminescence characteristic of the ligand appears (λmax = 508 nm, quantum yield = 10%). This change of the photoluminescence mechanism can be clarified by a combination of electrochemical and spectroscopic investigations. It can be demonstrated by cyclic voltammetry that new states appear in the hybrid as a consequence of D-A-D-SH binding to the nanocrystals surface. These states are located below the nanocrystal LUMO and above its HOMO, respectively. They are concurrent to deeper donor and acceptor states governing the red luminescence. As a result, energy transfer from the nanocrystal HOMO and LUMO levels to the ligand states takes place, leading to effective quenching of the red luminescence and appearance of the green one.
BLUE ELECTROCHROMIC COMPOUND, PREPARATION METHOD AND SUBASSEMBLY THEREOF
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Paragraph 0058; 0060, (2016/10/04)
One class of blue thiophene electrochromic compounds include 3,4-(2,2-bis(2-oxo-3-phenylpropyl))propylenedioxythiophene, 3,4-(2,2-bis(2-oxo-3-phenylbutyl))propylenedioxythiophene, and 3,4-(2,2-bis(2-oxo-3-phenylamyl))propylenedioxythiophene. The thiophene electrochromic compounds can change color between blue and transparency. The thiophene compounds can be electropolymerized on the surface of the ITO glass to form a film. The film has characteristics of low driving voltage (within ±1V), fast response time, and large transmittance difference between colored-state and bleached-state (up to 77.5%). The thiophene electrochromic compounds can be used in the electrochromic window, rearview mirror, electrochomeric display, and the like.
