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Diode characteristics and metal ion sensing features of a conjugated macromolecular system based on indolocarbazole-thiophene
摘要： A poly(indolocarbazole-thiophene) based high molecular weight polymer (ICZP3) was synthesized by Sonogashira coupling reaction and characterized by FTIR, 1H NMR, 13C NMR analysis. An enhanced solubility for it in organic solvents was achieved by the incorporation of alkyl chains on to the nitrogen atom of the backbone unit. It exhibits good thermal stability with interesting photonic performance, and processability. The incorporation of electron-transporting monomer moieties has been found to induce a balanced charge density in it, suitable for diode applications. Its conduction mechanism has been found to resemble well with the space charge limited current model, and involves Schottky type behaviour when assembled into an ITO/ICZP3/Al device fabricated. An interesting additional feature observed for ICZP3 is its very high Hg2+ sensing. The ICZP3 system is found to be a promising candidate for semiconductor applications and sensing.
关键词： Schottky diode,Metal sensing,Organic semiconductor,Poly(indolocarbazole-thiophene)
更新于2025-09-10 09:29:36
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Electrochemical gating of a hydrophobic organic semiconductor with aqueous media
摘要： We show that even the highly hydrophobic semiconducting polymer poly [2,5-bis(3-tetradecylthiophen-2-yl) thieno[3,2-b]thiophene] (PBTTT) can operate in organic electrochemical transistor (OECT) rather than field effect (OFET) mode when gated with aqueous media. The required bulk penetration of anions into the semiconducting film within the electrochemical window of water is here enabled by the choice of anion, namely, picric acid (PA). OECT mode operation in PBTTT films or its analogues had previously been seen only when gated with solid electrolytes with a larger electrochemical window, or for PBTTT analogues with hydrophilic sidechains. We assign the ability of PA anions to penetrate bulk PBTTT from their similarity to PBTTT solvents (chlorinated benzenes), in the sense that they both display an electron-deficient π electron system. In control experiments, we confirm that OECT mode is not observed when gating PBTTT with another organic acid (acetic acid) that does not display such π electron system, and that the gating mechanism indeed is electrochemical doping rather than a charge transfer mechanism. OECT mode is observed only at rather high PA concentrations in an aqueous gate medium (50 mM or more), but when it is, it leads to conductivities of ≈ 80 S/cm, slightly larger than for a PBTTT analogue with hydrophilic side chains gated with chloride anions.
关键词： regioregular poly(3-hexithiophene),organic electrochemical transistor,Picric Acid,Poly [2,5-bis (3-tetradecylthiophen-2-yl)thieno[3,2-b]thiophene]
更新于2025-09-10 09:29:36
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Impact of Precise Control over Microstructure in Thiophene–Selenophene Copolymers
摘要： Controlling the sequence of repeat units in a synthetic polymer has been a long-standing topic of interest in chemistry. As methods to regulate sequence become more sophisticated, it is critical to consider how controlling the arrangement of repeat units along the polymer backbone impacts properties. In this work, thiophene?selenophene copolymers (statistical and periodic) were compared to elucidate the impact of periodicity on electronic properties and structural organization in conjugated macromolecules. Polymers were synthesized using catalyst-transfer polycondensation (CTP) enabling control over molecular weight and dispersity. The study revealed that optical bandgaps and redox potentials of periodic and statistical copolymers varied with composition in a predictable manner, regardless of monomer ordering along the chain. While the bandgaps of the two types of copolymers were indistinguishable, X-ray scattering revealed di?erences in solid-state packing. Both types of copolymers exhibited well-de?ned morphologies, but larger π-stacking distances and more orientational disorder were evident in the statistical systems. This indicates periodicity is an attribute that should be considered when synthesizing semiconducting materials.
关键词： solid-state packing,periodicity,electronic properties,thiophene?selenophene copolymers,catalyst-transfer polycondensation
更新于2025-09-10 09:29:36
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Enhanced electrochromic performances of Polythieno[3,2-b]thiophene with multicolor conversion via embedding EDOT segment
摘要： A heterocyclic oligomer, thieno[3,2-b]thiophene (TT) end-capped famous 3,4-ethylenedioxythiophene (EDOT) unit and their electrosynthesized polymer P(TT-EDOT-TT) have been facilely achieved. To in-depth understand the effects of structural modification on physico-chemical properties and electrochromic performances of monomers and/or polymers, the absorption spectroscopy, electrochemistry, micromorphology, and spectro-electrochemistry were systematically studied. In contrast to TT and EDOT, TT-EDOT-TT possessed extended π-conjugation and narrowed band gap in molecular level. Through carefully comparison with PTT, it has been found that the electrochromic performances of P(TT-EDOT-TT) film exhibited much higher optical contrast (69%, while 3% for PTT in the near-infrared region) and superior coloring efficiency (255.3 cm2 C?1, while 36.8 cm2 C?1 for PTT), and switching times (within 1 s, while more than 9 s for PTT). Notably, P(TT-EDOT-TT) film can achieve the mutual conversion between RGB primary colors (red–green–blue) under variable voltages, which hold quite promising for display applications.
关键词： Conjugated polymers,Polythieno[3,2-b]thiophene,Electrochromism
更新于2025-09-10 09:29:36
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All-Thiophene-Based Double Helix: Synthesis, Crystal Structure, Chiroptical Property and Arylation
摘要： The all-thiophene-based double helix DH-1 was designed and prepared originally from the selective deprotonation of cyclooctatetrathiophene (tetra[3,4]thienylene, COTh) and following the Negishi coupling reaction with 3,3′-bithiophene. The X-ray crystallographic studies revealed that DH-1 has a double-helical scaffold. The arylations including tetraphenylation and tetrathienylation were efficiently employed to replace the four α-protons of the central COTh of DH-1 with phenyl and thiophenyl groups via cross-coupling reactions. The chiral resolution of rac-DH-1 was fulfilled via chiral high-performance liquid chromatography, and the chiroptical properties were characterized by circular dichroism spectra and optical rotation. Ultraviolet?visible absorption and fluorescence behaviors of DH-1 and its arylation products were also characterized to describe the extended conjugated scaffold.
关键词： ultraviolet?visible absorption,all-thiophene-based double helix,chiroptical properties,chiral resolution,Negishi coupling reaction,fluorescence behaviors
更新于2025-09-09 09:28:46
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Unraveling the Role of Π - Conjugation in Thiophene Oligomers for Optoelectronic Properties by DFT/TDDFT Approach
摘要： Thiophene oligomer has been investigated using DFT/TDDFT calculations with an aim to check its suitability for opto electronic applications and also to analyse the influence of π-bridge. Our results revealed that thiophene oligomers have excellent π-conjugation throughout. FMO analysis give an estimate of band gap of thiophene oligomer and further revealed HOMO are localized on π – bridge, donor group and LUMO are localized on π – bridge and acceptor group. A TDDFT calculation has been performed to understand the absorption properties of them in gas phase and solvent phase. PCM calculations convey that absorption maxima show positive solvatochromism. Among the designed candidates, the one with more π – bridge show higher wavelength of absorption maxima and would be a choice for better optoelectronic materials. NBO analysis provides support for complete delocalization in these systems. It is interesting to note that oligomer with more π–bridge display an enhanced optoelectronic properties than with less π – bridge.
关键词： Thiophene oligomer,TDDFT,π – bridge,PCM,NBO
更新于2025-09-09 09:28:46
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Photocatalytic hydrogen evolution from water using fluorene and dibenzothiophene sulfone conjugated microporous and linear polymers
摘要： Three series of conjugated microporous polymers (CMPs) were studied as photocatalysts for hydrogen production from water using a sacrificial hole scavenger. In all cases, dibenzo[b,d]thiophene sulfone polymers outperformed their fluorene analogs. A porous network, S-CMP3, showed the highest hydrogen evolution rate of 6076 μmol h-1 g-1 (λ > 295 nm) and 3106 μmol h-1 g-1 (λ > 420 nm), with an external quantum efficiency of 13.2% at 420 nm. S-CMP3 outperforms its linear structural analog, P35, while in other cases, non-porous linear polymers are superior to equivalent porous networks. This suggests that microporosity might be beneficial for sacrificial photocatalytic hydrogen evolution, if suitable linkers are used that do not limit charge-transport and the material can be wetted by water as studied here by water sorption and quasi-elastic neutron scattering.
关键词： fluorene,sacrificial hole scavenger,conjugated microporous polymers,photocatalytic hydrogen evolution,dibenzo[b,d]thiophene sulfone
更新于2025-09-04 15:30:14
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Construction of a Layered Hydrogen-Bonded Organic Framework Showing High-Contrast Mechanoresponsive Luminescence Turn-On
摘要： This paper probes the mechanoresponsive luminescence and aggregation-induced emission (AIE) properties of N-phenylcarbazole-based thiophene/dicyanovinyl (T?DCV) derivatives. In bis-T?DCV planar molecule 1, a layered hydrogen-bonded organic framework (HOF) structure is formed with the assistance of multiple C?H···N and strong interlayer interactions. The formation of such a layer packing HOF structure can quench the solid fluorescent emission when aggregated as nanosuspensions but guarantees the high-contrast luminescence on?off switching (1.2 × 103 fold) in the solid state. Moreover, the grinding-induced destruction of HOF 1 is reflected by powder X-ray diffraction measurements, in which the destruction of the α and β rings in the planar HOF stripe and the close interlayer stacking could be observed. This work achieves the successful construction of long-wavelength emission AIE molecules (2 and 3) by introducing sufficient steric hindrance rotors to disturb the intermolecular π?π stacking and/or dipole?dipole interactions.
关键词： high-contrast luminescence,aggregation-induced emission,mechanoresponsive luminescence,hydrogen-bonded organic framework,thiophene/dicyanovinyl derivatives
更新于2025-09-04 15:30:14
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Photopolymerization of electroactive film applied to full polymer electrochromic device
摘要： Electroactive films of thiophene-acrylate polymers were simultaneously photopolymerized by means of ultraviolet (UV) irradiation using diphenyliodonium hexafluorophosphate and acrylate special photoinitiators (PIs) as a mixed photoinitiator. Free radicals from PIs can promote cationic polymerization of thiophenes. Electrical conductivity and transmittance of the electroactive film are high to 10–2 S·cm–1 and >90%. Electroactivity of the photopolymerized polymer film was confirmed by electro-polymerization of aniline on this film in aqueous solution and employed to assemble a full polymer electrochromic device having a superior optical contrast of 36.6%.
关键词： electrochromic device,polymer blends and alloys,thiophene-acrylate polymer composites,photopolymerization,electroactive film
更新于2025-09-04 15:30:14
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Board‐like Fused‐Thiophene Liquid Crystals and Their Benzene Analogues: Facile Synthesis, Self‐assembly, p‐Type Semiconductivity, and Photoluminescence
摘要： Novel fused-thiophene discotic liquid crystals were designed and easily synthesized by Suzuki coupling and FeCl3 oxidized tandem cyclo-dehydrogenation reactions, including homo- and cross-coupling reactions. The resulting hexagonal and rectangular columnar mesomorphic supramolecular structures formed were characterized by polarizing optical microscopy, differential scanning calorimetry, and small-angle X-ray scattering. Charge carrier transport properties in the mesophases of two of the synthesized fused-thiophene discogens were measured by transient photocurrent time-of-flight (TOF) technique, revealing fast hole transport values in the range of 10-3 to 10-2 cm2 V-1s-1, thus demonstrating potential applications in electronic devices. The luminescent sanidic mesogens, having different extended π-conjugated systems, also emit blue, green or red light, with absolute photoluminescent quantum yields as high as 18%.
关键词： thiophene,luminescence,mesophase,cyclo-hydrogenation,charge mobility
更新于2025-09-04 15:30:14