Development and Characterization of Solution-Processable Dithieno[3,2-b : 2',3'-d]thiophenes Derivatives with Various End-capped Groups for Organic Field-Effect Transistors.

In this paper, four organic materials based on dithieno[3,2-b : 2',3'-d]thiophene (DTT) core structure with end-capping groups (phenyl and thienyl) and linker (acetylenic and olefinic) between DTT-core and end-capping groups were synthesized and characterized as solution-processable organic semiconductors (OSCs) for organic field-effect transistors (OFETs). Thermal, optical, and electrochemical properties of the corresponding materials were determined. Next, all DTT-derivatives were coated by solution-shearing method, and the thin-film microstructures and morphologies were investigated.

A molecular design towards sulfonyl aza-BODIPY based NIR fluorescent and colorimetric probe for selective cysteine detection.

Cysteine (Cys), homocysteine (Hcy) and glutathione (GSH) are essential biothiols for cellular growth, metabolism, and maintenance of a biological system. Thus, the detection of biothiols is highly important for early diagnosis and evaluation of disease progression. In this article, a series of sulfonyl aza-BODIPYs was synthesized, characterized, and examined by H-NMR, C-NMR, crystallization, photophysical properties and DFT calculation.

Versatile Solution-Processed Reductive Interface Layer for Contact Engineering of Staggered Organic Field-Effect Transistors.

Efficient charge injection/extraction from/to contact electrodes is essential to realize organic electronic and optoelectronic devices with optimum characteristics for many applications. Herein, we studied a versatile reductive interlayer based on sodium borohydride (NaBH) to control the contact properties of the staggered organic field-effect transistors (OFETs) either by doping and/or by regulating the contribution of charge carriers. The versatile functionalities of the NaBH layer are mainly determined by the alignment of frontier molecular orbitals of donor-acceptor (D-A) type copolymer semiconductors and the work function of the contact electrode.

Solution-Processable Diketopyrrolopyrrole Derivatives as Organic Semiconductors for Organic Thin-Film Transistors.

Solution-processable diketopyrrolopyrrole derivatives having acetylene, 2,5-bis(2-ethylhexyl)-3-(5-(phenylethynyl)thiophen-2-yl)-6-(thiophen-2-yl)-2,5-dihydropyrrolo[3,4-c]pyrrole-1,4-dione (3), 2,5-bis (2-ethylhexyl)-3-(thiophen-2-yl)-6-(5-(thiophen-2-ylethynyl)thiophen-2-yl)-2,5-dihydropyrrolo[3,4-c] pyrrole-1,4-dione (4), and 6,6'-((thiophene-2,5-diylbis(ethyne-2,1-diyl))bis(thiophene-5,2-diyl)) bis(2,5-bis(2-ethylhexyl)-3-(thiophen-2-yl)-2,5-dihydropyrrolo[3,4-c]pyrrole-1,4-dione) (5) were synthesized and characterized as organic semiconductors for organic thin-film transistors (OTFTs). For the fabrication of thin films based on solution processable compounds, drop-casting (DC) and solution-shearing (SS) were employed. Thin films of compound 5 exhibited p-channel characteristics with carrier mobility as high as 5.

Kinetics and Molecular Docking Studies of 6-Formyl Umbelliferone Isolated from Angelica decursiva as an Inhibitor of Cholinesterase and BACE1.

Coumarins, which have low toxicity, are present in some natural foods, and are used in various herbal remedies, have attracted interest in recent years because of their potential medicinal properties. In this study, we report the isolation of two natural coumarins, namely umbelliferone () and 6-formyl umbelliferone (), from , and the synthesis of 8-formyl umbelliferone () from . We investigated the anti-Alzheimer disease (anti-AD) potential of these coumarins by assessing their ability to inhibit acetylcholinesterase (AChE), butyrylcholinesterase (BChE), and β-site amyloid precursor protein (APP) cleaving enzyme 1 (BACE1).

Benzothiadiazole-Based Small-Molecule Semiconductors for Organic Thin-Film Transistors and Complementary-like Inverters.

New benzothiadiazole derivatives, 4,7-bis(5-phenylthiophen-2-yl)benzo[c][1,2,5]thiadiazole (PT-BTD) and 4,7-bis[4-(thiophen-2-yl)phenyl]benzo[c][1,2,5]thiadiazole (TP-BTD), were synthesized and characterized as small-molecule organic semiconductors for organic thin-film transistors (OTFTs) and complementary inverters. The thermal, optical, and electrochemical properties of the new compounds were fully characterized. Vacuum-deposition and solution-shearing methods were used to fabricate thin films based on these compounds.

Multifunctional Organic-Semiconductor Interfacial Layers for Solution-Processed Oxide-Semiconductor Thin-Film Transistor.

The stabilization and control of the electrical properties in solution-processed amorphous-oxide semiconductors (AOSs) is crucial for the realization of cost-effective, high-performance, large-area electronics. In particular, impurity diffusion, electrical instability, and the lack of a general substitutional doping strategy for the active layer hinder the industrial implementation of copper electrodes and the fine tuning of the electrical parameters of AOS-based thin-film transistors (TFTs). In this study, the authors employ a multifunctional organic-semiconductor (OSC) interlayer as a solution-processed thin-film passivation layer and a charge-transfer dopant.

Synthesis and Characterization of Benzothiadiazole Derivatives as Organic Semiconductors for Organic Thin-Film Transistors.

New benzothiadiazole derivatives end-functionalized with carbazole and a-carboline, 4,7-di(9H-carbazol-9-yl)benzo[c][1,2,5]thiadiazole (1) and 4-(9H-carbazol-9-yl)-7-(9H-pyrido[2,3-bindol-9-yl) benzo[c][1,2,5]thiadiazole (2) were synthesized and characterized as organic semiconductors for organic thin-film transistors (OTFTs). Thermal, optical, and electrochemical properties of the corresoponding compounds were characterized. Thin films of compound 1 exhibited p-channel characteristics with carrier mobility as high as 10⁻⁴ cm²/Vs and a current on/off ratio of 10⁵ for top-contact/bottom-gate OTFT devices.

Novel Organic Semiconductors Based on Phenyl and Phenylthienyl Derivatives for Organic Thin-Film Transistors.

New phenyl and phenylthienyl derivatives end-functionalized with carbazole and α-carboline, 9-(4- (9H-carbazol-9-yl)phenyl)-9H-carbazole, 9-(4-(9H-carbazol-9-yl)phenyl)-9H-pyrido[2,3-b]indole, 9-(3-(9H-carbazol-9-yl)phenyl)-9H-carbazole, 9-(3-(9H-carbazol-9-yl)phenyl)-9H-pyrido[2,3-b]indole, 9-(4-(5-(9H-carbazol-9-yl)thiophen-2-yl)phenyl)-9H-carbazole, and 9-(3-(5-(9H-carbazo-9-yl) thiophen-2-yl)phenyl)-9H-carbazole were synthesized and characterized as organic semiconductors for organic thin-film transistors (OTFTs). Most compounds exhibited p-channel characteristics with carrier mobility as high as 1.7 x 10⁻⁵ cm²/Vs and a current on/off ratio of 10²-10⁴ for top-contact/bottom-gate OTFT devices.

Indium triflate-catalyzed stereoselective tandem intramolecular conjugate addition of secondary amines to α,β-bisenones.

We report an indium triflate-catalyzed stereoselective intramolecular tandem conjugate addition of secondary amines to α,β-bisenones to afford a 1,2,3-trisubstituted six-membered ring bearing diketone substituents in good to excellent yields at room temperature. Various kinds of α,β-bisenones and amines were employed to expand the scope of this chemistry. Intramolecular trapping of indium-enolate by the tethered electrophiles resulted in the stereoselective formation of three contiguous stereogenic centers.

Structural and sequence features of two residue turns in beta-hairpins.

Beta-turns in beta-hairpins have been implicated as important sites in protein folding. In particular, two residue β-turns, the most abundant connecting elements in beta-hairpins, have been a major target for engineering protein stability and folding. In this study, we attempted to investigate and update the structural and sequence properties of two residue turns in beta-hairpins with a large data set.

Immobilization of proteins onto poly(2-hydroxyethyl methacrylate) functionalized Fe-Au/core-shell nanoparticles via adsorption strategy.

Biocompatible magnetic nanocomposites of Fe-AuNPs and poly(2-hydroxylethyl methacrylate) (PHEMA) were employed as a strategic protein immobilization platform. The hybrid magnetic nanocomposites were prepared by applying a 'grafting to' ATRP protocol. Fe-AuNPs having Fe core and Au shell were initially prepared by the inverse micelle method.

Lanthanide-catalyst-mediated tandem double intramolecular hydroalkoxylation/cyclization of dialkynyl dialcohols: scope and mechanism.

Lanthanide-organic complexes of the general type [Ln{N(SiMe(3))(2)}(3)] (Ln=La, Sm, Y, Lu) serve as effective precatalysts for the rapid, exo-selective, and highly regioselective tandem double intramolecular hydroalkoxylation/cyclization of primary and secondary dialkynyl dialcohols to yield the corresponding bi-exocyclic enol ethers. Conversions are highly selective with products distinctly different from those generally produced by conventional transition metal or other catalysts, and the turnover frequencies with some substrates are too large to determine accurately. The rates of terminal alkynl alcohol hydroalkoxylation/cyclization are significantly more rapid than those of internal alkynyl alcohols, arguing that steric demands dominate the cyclization transition state.

Mild amidation of aldehydes with amines mediated by lanthanide catalysts.

Catalytic amidation of aldehydes with amines is efficiently mediated by homoleptic lanthanide amido complexes, Ln[N(SiMe3)2]3 (Ln = La, Sm, and Y). Amidation reactivity follows the trend: La > Sm approximately Y. These reactions proceed in high yield without added oxidants, bases, and/or heat or light, which are usually required in other catalytic amidation processes.