Search results for " molecule"
showing 10 items of 1523 documents
Exercise-Driven Increase in Gut Microbial Hydrogen Production as a Possible Factor of Metabolic Health
2020
Di-n-butyltin oxide as a chemical carbon dioxide capturer
2010
Abstract Several synthetic routes to the decakis(di-n-butyltin(IV)) oxocluster, (n-Bu2SnO)6[(n-Bu2SnOCH3)2(CO3)]2 (1), a diorganotin compound previously shown to belong to the class of organotins able to store carbon dioxide, as well as its reactivity toward dimethyl carbonate (DMC), are described. The synthetic route from n-Bu2SnO and DMC was applied for the preparation of the ethoxy analogue of 1, oxocluster 2, using diethyl carbonate. The structural relationship connecting cluster 1, with its precursor PRE-1 isolated from recycling experiments and n-Bu2SnO is discussed. For this purpose, the reactivity of PRE-1 with trifluoromethanesulfonic acid was investigated in order to trace structu…
Tuning the electronic properties and the planarity degree in the π-extended TTF series: the prominent role of heteroatoms
2018
The main asset of small molecules for application in organic electronics lies in the tunability of their electronic properties owing to the precise control of their molecular design. Semiconducting properties in organic compounds are for instance closely linked to the molecular planarity degree, including when considering various redox states. Among those species, the π-extended TTF (exTTF: 9,10-bis(1,3-dithiol-2-ylidene)-9,10-dihydroanthracene) presents fascinating redox and structural properties, which have been extensively studied in various fields of organic electronics. Here we show that S-exTTF, a sulfur enriched π-isoelectronic dithieno analogue of pristine exTTF, synthesized through…
The Synthesis, Condensation, and Luminescence of Stilbenoid Oligomers with Alkoxysilane End Groups
2001
ABSTRACTA synthetic route to highly luminescent organic semiconductors with curable alkoxysilyl groups is described. Monodisperse oligo(phenylenevinylene)s are rigidly connected to di- and triethoxysilanes via Heck reactions or via cross-metathesis. Hydrolysis of the silicic esters yields silanols condensing to linear and cyclic oligo-OPV-siloxanes or to three-dimensional networks, thus allowing the transformation of small molecules to fluorescent materials with well-defined chromophores. Transparent films are obtained by casting of soluble cyclosiloxanes and from OPV-silanetriols, the latter can be cured to insoluble networks.
Differential Effects of Tenofovir/Emtricitabine and Abacavir/Lamivudine on Human Leukocyte Recruitment
2012
Background The association of abacavir (ABC) with cardiovascular disease has led to HIV treatment guidelines favouring the combination of tenofovir/emtricitabine (TDF/FTC) over that of ABC/lamivudine (ABC/3TC). We have analysed the effects of plasma-relevant concentrations of TDF, FTC, ABC and 3TC, individually and in clinically employed combinations, on human leukocyte accumulation. The effects of ABC, 3TC, TDF and FTC on the expression of adhesion molecules were also evaluated. Methods Interactions between human leukocytes – specifically peripheral blood polymorphonuclear or mono-nuclear cells – and human umbilical vein endothelial cells were evaluated in a flow chamber reproducing in viv…
New heteronuclear gold(I)-platinum(II) complexes with cytotoxic properties: are two metals better than one?
2014
A series of mono- and heterodinuclear gold(I) and platinum(II) complexes with a new bipyridylamine-phosphine ligand have been synthesized and characterized. The X-ray structures of the ligand precursor 4-iodo-N,N-di(pyridin-2-yl)benzamide, and of one gold derivative are reported. All the complexes display antiproliferative properties in vitro in human cancer cells in the range of cisplatin or higher, which appear to correlate with compounds' uptake. Interestingly, studies of the interactions of the compounds with models of DNA indicate different mechanisms of actions with respect to cisplatin. The biological activity study of these complexes provides useful information about the interest of…
Lower Rydberg series of methane: a combined coupled cluster linear response and molecular quantum defect orbital calculation.
2006
Vertical excitation energies as well as related absolute photoabsorption oscillator strength data are very scarce in the literature for methane. In this study, we have characterized the three existing series of low-lying Rydberg states of CH4 by computing coupled cluster linear response (CCLR) vertical excitation energies together with oscillator strengths in the molecular-adapted quantum defect orbital formalism from a distorted Cs geometry selected on the basis of outer valence green function calculations. The present work provides a wide range of data of excitation energies and absolute oscillator strengths which correspond to the Rydberg series converging to the three lower ionization p…
Oxidative Coupling Reactions of 1,3-Diarylpropene Derivatives to Dibenzo[a,c]cycloheptenes by PIFA
2011
The oxidative cyclization reactions of a variety of α-benzyl-cinnamates can be selectively performed with hypervalent iodine as an oxidant. The dibenzo[a,c]cycloheptenes were isolated in up to 55 % yield. When an oxo substrate is applied, the yield was significantly increased. With this synthetic approach, a central intermediate for the synthesis of metasequirin-B was obtained in three steps from very simple starting materials. For this transformation, both aryl moieties have to be activated.