ABSTRACT
Planar backbone, locked conformation, and low lowest unoccupied molecular orbital level provide polymer F4 BDOPV-2T with ultrahigh electron mobilities of up to 14.9 cm(2) V(-1) s(-1) and good air stability. It is found that the nonlinear transfer curves can be tuned to near-ideal ones by changing fabrication conditions, indicating that film morphology largely contributes to the nonlinear transfer curves in high-mobility conjugated polymers.
ABSTRACT
The first copper-catalyzed intermolecular dearomatization of indoles by an asymmetric propargylic substitution reaction was developed. This method provides a highly efficient synthesis of versatile furoindoline and pyrroloindoline derivatives containing a quaternary carbon stereogenic center and a terminal alkyne moiety with up to 86 % yield and 98 % ee.
Subject(s)
Copper/chemistry , Indoles/chemistry , Indoles/chemical synthesis , Catalysis , Molecular Structure , StereoisomerismABSTRACT
The charge carrier mobility of p-type and ambipolar polymer field-effect transistors (FETs) has been improved substantially. Nonetheless, high-mobility n-type polymers are rare, and few can be operated under ambient conditions. This situation is mainly caused by the scarcity of strong electron-deficient building blocks. Herein, we present two novel electron-deficient building blocks, FBDOPV-1 and FBDOPV-2, with low LUMO levels down to -4.38 eV. On the basis of both building blocks, we develop two poly(p-phenylene vinylene) derivatives (PPVs), FBDPPV-1 and FBDPPV-2, for high-performance n-type polymer FETs. The introduction of the fluorine atoms effectively lowers the LUMO levels of both polymers, leading to LUMO levels as low as -4.30 eV. Fluorination endows both polymers with not only lower LUMO levels, but also more ordered thin-film packing, smaller π-π stacking distance, stronger interchain interaction and locked conformation of polymer backbones. All these factors provide FBDPPV-1 with high electron mobilities up to 1.70 cm(2) V(-1) s(-1) and good stability under ambient conditions. Furthermore, when polymers have different fluorination positions, their backbone conformations in solid state differ, eventually leading to different device performance.
ABSTRACT
An efficient and direct protocol for the preparation of amidoalkylnaphthols employing a multi-component, one-pot condensation reaction of 2-naphthol, aromatic aldehydes and acetamide or benzamide in the presence of graphite supported perchloric acid under solvent-free conditions is described. The thermal solvent-free procedure offers advantages such as simple work-up, shorter reaction times and higher product yields, and the catalyst exhibited remarkable reactivity and can be recycled.
Subject(s)
Chemistry, Organic/methods , Graphite/chemistry , Naphthols/chemical synthesis , Perchlorates/chemistry , Recycling , Catalysis , Naphthols/chemistryABSTRACT
Two functional main-chain linear polyrotaxanes, one a covalent polymeric chain that threads through many macrocycles (P1) and the other a poly[n]rotaxane chain that is composed of many repeating rotaxane units (P2), were synthesized by employing strong crown-ether/ammonium-based (DB24C8/DBA) host-guest interactions and click chemistry. Energy transfer between the wheel and axle units in both polyrotaxanes was used to provide insight into the conformational information of their resulting polyrotaxanes. Steady-state and time-resolved spectroscopy were performed to understand the conformation differences between polymers P1 and P2 in solution. Additional investigations by using dynamic/static light scattering and atomic force microscopy illustrated that polymer P1 was unbending and had a rigid rod-like structure, whilst polymer P2 was curved and flexible. This flexible topology facilitated the self-assembly of polymer P2 into relatively large ball-shaped particles. In addition, the energy transfer between the wheel and axle units was controlled by the addition of specific anions or base. The anion-induced energy enhancement was attributed to a change in electrostatic interactions between the polymer chains. The base-driven molecular shuttle broke the DB24C8/DBA host-guest interactions. These results confirm that both intra- and intermolecular electrostatic interactions are crucial for modulating conformational topology, which determines the assembly of polyrotaxanes in solution.
ABSTRACT
Ambipolar transport behavior in isoindigo-based conjugated polymers is observed for the first time. Fluorination on the isoindigo unit effectively lowers the LUMO level of the polymer and significantly increases the electron mobility from 10(-2) to 0.43 cm(2) V(-1) s(-1) while maintaining high hole mobility up to 1.85 cm(2) V(-1) s(-1) for FET devices fabricated in ambient. Further investigation indicates that fluorination also affects the interchain interactions of polymer backbones, thus leading to different polymer packing in thin films.
ABSTRACT
Two conjugated polymers, IIDDT and IIDT, based on an isoindigo core were developed for organic field-effect transisitors. Investigation of their field-effect performance indicated that IIDDT exhibited air-stable mobility up to 0.79 cm(2) V(-1) s(-1), which is quite high among polymer FET materials. The facile preparation and high mobility of such polymers make isoindigo-based polymers very promising for application as solution-processable organic semiconductors for optoelectronic devices.
ABSTRACT
An efficient synthesis of novel 1-aryl-3-(indole-3-yl)-3-(2-aryl-1,2,3-triazol-4-yl)propan-1-ones from indoles and 1-aryl-3-(2-aryl-1,2,3-triazol-4-yl)propan-1-one using a Brønsted acid ionic liquid [Sbmim][HSO4] as catalyst is described. Satisfactory results with excellent yields and short reaction time were obtained in the experiments. The catalyst could be recovered conveniently and reused efficiently.
Subject(s)
Indoles/chemistry , Indoles/chemical synthesis , Ionic Liquids/chemistry , Ketones/chemistry , Ketones/chemical synthesis , Propane/chemistry , CatalysisABSTRACT
An efficient synthesis of novel 4-(2-phenyl-1,2,3-triazol-4-yl)-3,4-dihydro-pyrimidin-2(1H)-(thio)ones from 1,3-dicarbonyl compounds, 2-phenyl-1,2,3-triazole-4-carbaldehyde and urea or thiourea under ultrasound irradiation and using samarium perchlorate as catalyst is described. Compared with conventional methods, the main advantages of the present methodology are milder conditions, shorter reaction times and higher yields.
Subject(s)
Anti-Bacterial Agents/chemical synthesis , Anti-Inflammatory Agents, Non-Steroidal/chemical synthesis , Antineoplastic Agents/chemical synthesis , Antiviral Agents/chemical synthesis , Perchlorates/chemistry , Pyrimidinones/chemical synthesis , Samarium/chemistry , Triazoles/chemical synthesis , Anti-Bacterial Agents/chemistry , Anti-Inflammatory Agents, Non-Steroidal/chemistry , Antineoplastic Agents/chemistry , Antiviral Agents/chemistry , Catalysis , Pyrimidinones/chemistry , Thiourea/chemistry , Triazoles/chemistry , Ultrasonics , Urea/chemistryABSTRACT
The Brønsted acid ionic liquid [PyN(CH(2))(4)SO(3)H][p-CH(3)PhSO(3)] has been reported as an efficient catalyst for the Michael addition reaction of indoles to alpha,beta-unsaturated ketones. Satisfactory results were obtained, with excellent yields and a simple experimental procedure. The catalyst could be recycled and reused up to three times without any noticeable decrease in the catalytic activity.
Subject(s)
Acids/chemistry , Indoles/chemistry , Ionic Liquids/chemistry , Ketones/chemistry , Catalysis , Chalcone/chemistry , Ketones/chemical synthesisABSTRACT
A series of novel bis(substituted pyrazol-4-ylcarbonyl)-substituted thioureas have been synthesized by the reactions of substituted pyrazol-4-ylcarbonyl isothiocyanates with different diamines under ultrasound irradiation and classical heating method at 20-25 degrees C. In general, substantial improvement in rates and modest yields increases were observed when reactions were carried out under sonication, compared with the classical heating method. The structures of these compounds have been elucidated by elemental and spectral (IR, (1)H-NMR) analysis.
Subject(s)
Pyrazoles/chemistry , Thiourea/chemistry , Hot Temperature , Molecular Structure , UltrasonicsABSTRACT
A simple, efficient procedure for the one-pot Biginelli condensation reaction of aldehydes, beta-ketoesters and urea or thiourea employing copper(II) sulfamate as a novel catalyst is described. Compared to the classical Biginelli reaction conditions, the present method has the advantages of good yields, short reaction times and experimental simplicity.
Subject(s)
Copper/chemistry , Pyrimidinones , Sulfonic Acids/chemistry , Thiones , Acetates/chemistry , Aldehydes/chemistry , Catalysis , Molecular Structure , Pyrimidinones/chemical synthesis , Pyrimidinones/chemistry , Thiones/chemical synthesis , Thiones/chemistry , Urea/chemistryABSTRACT
In the crystal structure of the title compound, C(23)H(22)N(6)O(2)S(2), there are two intra-molecular N-Hâ¯O hydrogen bonds. The propyl chain is disordered over two sites, with occupancy factors of 0.639â (5) and 0.361â (5).