4,5-Diazafluorene co-oligomers as electrondeficientlight-emitting materials and selectivefluorescence sensors for mercury(II) cations

4,5-Diazafluorene co-oligomers combine improved electron affinity with strong fluorescence and can be used as electron transporting and light-emitting materials, as well as fluorescent sensors for Hg2+ cations.</p

3,4-Phenylenedioxythiophenes (PheDOTs) functionalized with electron-withdrawing groupsand their analogs for organic electronics. Remarkably efficient tuning the energy levels in flatconjugated polymers

A novel, facile and efficient one-pot, microwave-assisted method of synthesis allowing an access to a new series of 3,4-phenylenedioxythiophene derivatives with electron-withdrawing groups at the benzene ring (EWG-PheDOT) and their analogs (with an expanded side π-system or with heteroaromatic rings, ArDOT) by the reaction of 2,5-dialkoxycarbonyl-3,4-dihydroxythiophenes with electrophilic aromatic/heteroaromatic compounds in dipolar aprotic solvents has been described. Its applicability over a wide range of novel functionalized ArDOTs as promising building blocks for organic electronic materials has been demonstrated. The structures of selected ArDOTs have been determined by single-crystal X-ray diffraction. The electronic structure of conjugated polymers p[ArDOTs] based on synthesized novel thiophene monomers has been studied theoretically by the DFT PBC/B3LYP/6-31G(d) method. The performed calculations reveal that while the side functional groups are formally not in conjugation with the polymer main chain, they have an unprecedentedly strong effect on the HOMO/LUMO energy levels of conjugated polymers, allowing their efficient tuning by over the range of 1.6 eV. In contrast to that, the energy gaps of the polymers are almost unaffected by such functionalizations and vary within a range of only ≤0.05 eV. Computational predictions have been successfully confirmed in experiments: cyclic voltammetry shows a strong anodic shift of p-doping for the electron-withdrawing CF3 group functionalized polymer p[4CF3-PheDOT] relative to the unsubstituted p[PheDOT] polymer (by 0.55 V; DFT predicted the decrease of the HOMO by 0.58 eV), while very similar Vis-NIR absorption spectra for both polymers in the undoped state indicate that their optical energy gaps nearly coincide (ΔEg &lt; 0.04 eV). © 2018 The Royal Society of Chemistry

Copper(II) complexes of functionalized 2,2’:6’,2’’-terpyridines and 2,6-di(thiazol-2-yl)pyridine : structure, spectroscopy, cytotoxicity and catalytic activity

Six new copper(II) complexes with 2,2’:6’,2’’-terpyridine (4’-Rn-terpy) [1 (R1 = furan-2-yl), 2 (R2 = thiophen- 2-yl), and 3 (R3 = 1-methyl-1H-pyrrol-2-yl)] and 2,6-di(thiazol-2-yl)pyridine derivatives (Rn-dtpy) [4 (R1), 5 (R2), and 6 (R3)] have been synthesized by a reaction between copper(II) chloride and the corresponding ligand. The complexes have been characterized by UV-vis and IR spectroscopy, and their structures have been determined by X-ray analysis. The antiproliferative potential of copper(II) complexes of 2,2’:6’,2’’-terpyridine and 2,6-di(thiazol-2-yl)pyridine derivatives towards human colorectal (HCT116) and ovarian (A2780) carcinoma as well as towards lung (A549) and breast adenocarcinoma (MCF7) cell lines was examined. Complex 1 and complex 6 were found to have the highest antiproliferative effect on A2780 ovarian carcinoma cells, particularly when compared with complex 2, 3 with no antiproliferative effect. The order of cytotoxicity in this cell line is 6 > 1 > 5 > 4 > 2 ≈ 3. Complex 2 seems to be much more specific towards colorectal carcinoma HCT116 and lung adenocarcinoma A549 cells. The viability loss induced by the complexes agrees with Hoechst 33258 staining and typical morphological apoptotic characteristics like chromatin condensation and nuclear fragmentation. The specificity towards different types of cell lines and the low cytotoxic activity towards healthy cells are of particular interest and are a positive feature for further developments. Complexes 1–6 were also tested in the oxidation of alkanes and alcohols with hydrogen peroxide and tert-butyl-hydroperoxide (TBHP). The most active catalyst 4 gave, after 120 min, 0.105 M of cyclohexanol + cyclohexanone after reduction with PPh3. This concentration corresponds to a yield of 23% and TON = 210. Oxidation of cis-1,2-dimethylcyclohexane with m-CPBA catalyzed by 4 in the presence of HNO3 gave a product of a stereoselective reaction (trans/cis = 0.47). Oxidation of secondary alcohols afforded the target ketones in yields up to 98% and TON = 630

Synthesis and Properties New Derivatives of 3,4-Phenylenedioxythiophene

This work was supported by the Russian President PhD Scholarship for studying abroad and by an Act 211 Government of the Russian Federation for financial support (contract No 02.A03.21.0006)

Synthesis of (±)-thiohalenaquinone by iterative metalations of thiophene

The synthesis of a thiophene-containing analogue of halenaquinone was realized. Key steps include an alkynyl ketone-benzocyclobutane Diels-Alder reaction to construct the C,D-ring naphthalene subunit, a Heck cyclization to form the quaternary carbon, and a ring closing metathesis to add the A-ring. © 2007 American Chemical Society