Search results for "thiophenes"
showing 10 items of 80 documents
Symmetric naphthalenediimidequaterthiophenes for electropolymerized electrochromic thin films
2015
A new symmetric naphthalenediimidequaterthiophene (s-NDI2ODT4) was synthesized and exhibited the capability to electropolymerize alone or with EDOT affording polymers with controlled donor/acceptor monomer ratios. s-NDI2ODT4-EDOT-based copolymers showed low band gaps, wide optical absorption ranges extending to the near IR region, tuned electrical properties, thin-film surface morphology and hydrophilicity as well as high coloration efficiency in electrochromic devices.
Multicomponent Synthesis of Benzothiophen-2-acetic Esters by a Palladium Iodide Catalyzed S-cyclization – Alkoxycarbonylation Sequence
2021
A catalytic carbonylative approach to the multicomponent synthesis of benzothiophene derivatives from simple building blocks [1-(2-(methylthio)phenyl)prop-2-yn-1-ols, carbon monoxide, and an alcohol)] is presented. It is based on an S-cyclization-demethylation-alkoxycarbonylation-reduction sequence promoted by the PdI2/KI catalytic system, occurring under relatively mild conditions (40 atm, 80 °C, 15 h). Benzothiophene-2-acetic esters are obtained in moderate to good yields (35–70%) starting from variously substituted substrates in combination with different alcohols as external nucleophiles (17 examples). (Figure presented.).
Spectroscopic signatures for planar equilibrium geometries in methyl-substituted oligothiophenes
2009
In recent studies it was demonstrated that temperature-dependent optical spectroscopy is a valuable tool for revealing the differences in the geometries of flexible molecules like oligothiophenes (OTs) in the ground (S0) and first excited (S1) electronic states, by examining the symmetry relations between the absorption and emission spectra: while at low temperature the spectra show mirror symmetry, pointing to planar geometries in S0 and S1, the symmetry relation breaks down at ambient temperature due to thermal population of torsional modes. In the present joint spectroscopic and theoretical study, we demonstrate that this behavior is also observed for di- and tetramethyl-substituted OTs,…
Multi-channel receptors based on thiopyrylium functionalised with macrocyclic receptors for the recognition of transition metal cations and anions.
2010
We report herein the synthesis and characterization of a family of ligands containing different cation binding sites covalently connected to a thiopyrylium signalling reporter. The receptors L1–L6 are able to signal the presence of certain metal cations via three different channels; i.e. electrochemically, fluorogenically and chromogenically. An acetonitrile solution of L1–L6 shows a bright blue colour due to a charge-transfer band in the 575–585 nm region. The colour variation in acetonitrile of L1–L6 in the presence of the metal cations Ag+, Cd2+, Cu2+, Fe3+, Hg2+, Ni2+, Pb2+ and Zn2+ has been studied. A selective hypsochromic shift of the blue band was found for the systems L4-Pb2+ and L…
Potential drug-drug interaction between duloxetine and acenocoumarol in a patient with Alzheimer's disease
2007
Abstract Background : Recent evidence suggests that duloxetine may increase the effect of warfarin, thereby increasing the possibility of bleeding. However, a MEDLINE search for articles published between 1980 and May 2007 (terms: duloxetine , anticoagulants , acenocoumarol , and interaction ; no language restriction) did not yield any reports of an interaction between concomitant use of duloxetine and acenocoumarol. Objective : The aim of this study was to describe a potential drug-drug interaction between duloxetine and acenocoumarol in a patient with Alzheimer's disease. The possible mechanism of this potential interaction is examined. Case summary : This report presents the case of a 63…
The new frontier of bone formation: a breakthrough in postmenopausal osteoporosis?
2009
Osteoporosis is a chronic disease that accelerates after menopause in many women. Most of the pharmacologic attempts to control the disease, such as hormone therapy, have emphasized the constraint of bone resorption. Since recent years have witnessed important advances in the field of bone formation, this review aims to update the present knowledge on the mechanisms affecting osteoblastogenesis and on the therapeutic results achieved by recently approved drugs.We sought peer-reviewed, full-length basic and clinical articles published between 1995 and May 2008 using a PubMed search strategy, with the terms osteoporosis and osteoblast, osteoporosis and strontium ranelate, and osteoporosis and…
Managing Bleeding Complications in Patients Treated with the Old and the New Anticoagulants
2010
An increasing number of patients receive anticoagulant therapy to prevent and treat arterial or venous thromboembolism. The major complication of anticoagulant therapy is the increase of the individual bleeding risk. All anticoagulant drugs can cause haemorrhages, that can sometimes be life-threatening. Although heparins and the vitamin K antagonists have been the most widely used anticoagulants for decades, the correct management of bleeding complications associated with these agents has been poorly studied. More recently, new anticoagulant drugs, both parenteral and oral, have been approved for clinical use. Currently, none of these new agents has a specific antidote, and little advise ca…
Solvatochromic behaviour of new donor–acceptor oligothiophenes
2021
Oligothiophene derivatives play a central role in the formulation of materials used in devices in the field of organic electronics. In this work, we report the results of the study of UV-vis absorption and fluorescence spectra, in several solvents, of a series of oligothiophenes recently synthesized in our laboratory. The studied oligothiophenes present different structures due to several factors: the donor– acceptor (D–A) or acceptor–donor–acceptor (A–D–A) architecture, the number of thiophene rings in the backbone (ranging from three to eight), the number and position of solubilizing octyl chains in the backbone, and the type of acceptor moieties (from Knoevenagel condensation either with…
Preparation of tungstophosphoric acid/cerium-doped NH2-UiO-66 Z-scheme photocatalyst: a new candidate for green photo-oxidation of dibenzothiophene a…
2021
International audience; The goal of this study was to introduce an effective visible-light induced photocatalytic system with a good ability for photocatalytic oxidative desulfurization (PODS) and denitrogenation (PODN) using molecular oxygen (O2) as an oxidant. In this regard, tungestophosphoric acid (PW12) was supported onto cerium-doped NH2-UiO-66 (PW12/Ce-NUiO-66) and employed for the photo-oxidation of dibenzothiophene (DBT) and quinoline (Qu). Herein, using cerium (Ce) as a “mediator” facilitated the separation of charge carriers, while NH2-UiO-66 remarkably enhanced the surface area with plentiful adsorption sites and shifted the adsorption edge of PW12to the visible region. The sum …
Synthesis, antiproliferative activity, and in silico insights of new 3-benzoylamino-benzo[ b ]thiophene derivatives
2014
A new series of 3-benzoylamino-5-imidazol-5-yl-benzo[b]thiophenes and the parent amino derivatives were synthesized and screened as antitumor agents. All tested compounds showed concentration-dependent antiproliferative activity profile against HeLa cell line, exhibiting GI50 values in the low micromolar range. The most active compounds were tested in cell cycle perturbation experiments. A rapid accumulation of cells in the G2/M phase, with a concomitant reduction of cells in both the S and G0/G1 phases, was observed, suggesting that cell exposure to selected derivatives produces mitotic failure. To rationalize the biological results, the 3-benzoylamino-benzo[b]thiophenes were analyzed thro…