118 research outputs found
CCDC 1504746: Experimental Crystal Structure Determination
No full textRelated Article: Marina S. Zavakhina, Irina V. Yushina, Denis G. Samsonenko, Danil N. Dybtsev, Vladimir P. Fedin, Stephen P. Argent, Alexander J. Blake, Martin Schröder|2017|Dalton Trans.|46|465|doi:10.1039/C6DT03969
CCDC 1504745: Experimental Crystal Structure Determination
No full textRelated Article: Marina S. Zavakhina, Irina V. Yushina, Denis G. Samsonenko, Danil N. Dybtsev, Vladimir P. Fedin, Stephen P. Argent, Alexander J. Blake, Martin Schröder|2017|Dalton Trans.|46|465|doi:10.1039/C6DT03969
Arene-ruthenium(II) complexes with tetracyclic oxime derivatives: synthesis, structure and antiproliferative activity against human breast cancer cells
No full textSix new arene-ruthenium(II) complexes containing two different η6-arene ligands – benzene and hexame- thylbenzene, with indenoquinoxalinone oxime analogues (11H-indeno[1,2-b]quinoxalin-11-one oxime, 6H- indeno[1,2-b]pyrido[3,2-e]pyrazin-6-one oxime and 6–(hydroxyimino)indolo[2,1-b]quinazolin-12(6H)-one oxime (tryptanthrin-6-oxime)) as N,N’- chelating ligands are reported. The complexes were characterized by elemental analysis, IR, UV–VIS, 1H and 13C NMR spectroscopy and by single-crystal X-ray structure analysis. Complexes adopt a half-sandwich «piano-stool» geometry with oxime ligands in anionic form, the ruthenium(II) center coordinates one arene, one N,N-bidentate oximate and one chloride ligand. The computational analysis of non-covalent intermolecular interactions revealed weak attraction between the oxime oxygen atoms and the nearest hydrogen atoms of the oxime and the arene ligands. The cytotoxic activity of the complexes was eval- uated against human breast cancer cell line MCF-7 and cisplatin-resistant human breast cancer cell line MCF-7CR as well as non-cancerous human breast epithelial cell line MCF10A. The cytotoxicity tests show micromolar IC50 values and tryptanthrin-6-oxime hexamethylbenzene-ruthenium(II) complex was found to exhibit the best antiproliferative activity among the studied compounds against the MCF-7 and MCF-7CR cell lines (IC50 9.0 ± 4.4 and 8.9 ± 1.5 μM, respectively)
Enhancement of CO2 Uptake and Selectivity in a Metal-Organic Framework by the Incorporation of Thiophene Functionality
No full textThe complex [Zn2(tdc)2dabco] (H2tdc = thiophene-2,5-dicarboxylic acid; dabco = 1,4-diazabicyclooctane) shows a remarkable increase in carbon dioxide (CO2) uptake and CO2/dinitrogen (N2) selectivity compared to the nonthiophene analogue [Zn2(bdc)2dabco] (H2bdc = benzene-1,4-dicarboxylic acid; terephthalic acid). CO2 adsorption at 1 bar for [Zn2(tdc)2dabco] is 67.4 cm3·g–1 (13.2 wt %) at 298 K and 153 cm3·g–1 (30.0 wt %) at 273 K. For [Zn2(bdc)2dabco], the equivalent values are 46 cm3·g–1 (9.0 wt %) and 122 cm3·g–1 (23.9 wt %), respectively. The isosteric heat of adsorption for CO2 in [Zn2(tdc)2dabco] at zero coverage is low (23.65 kJ·mol–1), ensuring facile regeneration of the porous material. Enhancement by the thiophene group on the separation of CO2/N2 gas mixtures has been confirmed by both ideal adsorbate solution theory calculations and dynamic breakthrough experiments. The preferred binding sites of adsorbed CO2 in [Zn2(tdc)2dabco] have been unambiguously determined by in situ single-crystal diffrac..
Organic-inorganic hybrid iodobismuthate, [Bi(L) 4 (H 2 O)]Bi 3 I 12 , based on tris(2-pyridyl)phosphine oxide (L): Synthesis, structure and air-oxidation into [Bi(L) 4 ] 2 [Bi 4 I 16 (I 3 ) 2 ]
No full text
Asymmetric Autoamplification in the Oxidative Kinetic Resolution of Secondary Benzylic Alcohols Catalyzed by Manganese Complexes
No full textChemInform Abstract: Titanium Salan Catalysts for the Asymmetric Epoxidation of Alkenes: Steric and Electronic Factors Governing the Activity and Enantioselectivity.
No full textSynthesis, Characterization and Structural Study of the Two Ionic Hydrogen-Bonded Organic Frameworks Based on Sterically Crowded Bifunctional Moieties
No full textSmall bifunctional molecules are attractive for use as models in different areas of knowledge. How can their functional groups interact in solids? This is important to know for the prediction of the physical and chemical properties of the materials based on them. In this study, two new hydrogen-bonded organic frameworks (HOFs) based on sterically demanding molecular compounds, bis(1-hydroxy-2-methylpropane-2-aminium) sulfate (1) and 2-methyl-4-oxopentan-2-aminium hydrogen ethanedioate hydrate (2), were synthesized and fully characterized by means of FTIR and NMR spectroscopies, as well as by X-ray powder diffraction and thermogravimetric analyses. Their molecular and crystal structures were established through single-crystal X-ray diffraction analysis. It was shown that both compounds have a layered structure due to the formation of a 2D hydrogen-bonding network, the layers being linked by systematically arranged Van der Waals contacts between the methyl groups of organic cations. To unveil some dependencies between the chemical nature of bifunctional molecules and their solid structure, Hirschfeld surface (HS) analysis was carried out for HOFs 1, 2, and their known congeners 1-hydroxy-2-methylpropan-2-aminium hemicarbonate (3) and 1-hydroxy-2-methylpropan-2-aminium (1-hydroxy-2-methylpropan-2-yl) carbamate (4). HS was performed to quantify and visualize the close intermolecular atomic contacts in the crystal structures. It is clearly seen that H–H contacts make the highest contributions to the amino alcohol based compounds 1, 3 and 4, with a maximal value of 65.2% for compound 3 having CO32− as a counterion. A slightly lower contribution of H–H contacts (64.4%) was found for compound 4, in which the anionic part is represented by 1-hydroxy-2-methylpropan-2-yl carbamate. The significant contribution of the H–H contacts in the bifunctional moieties is due to the presence of a quaternary carbon atom with a short three-carbon chain
EPR Spectroscopic Detection of the Elusive Fe<sup>V</sup>O Intermediates in Selective Catalytic Oxofunctionalizations of Hydrocarbons Mediated by Biomimetic Ferric Complexes
No full textHerein, we report the EPR spectroscopic
study of the bioinspired
catalyst systems for selective hydrocarbon oxofunctionalizations based
on dinuclear ferric complexes with TPA* and PDP* aminopyridine ligands,
hydrogen peroxide, and acetic acid (TPA* = tris(3,5-dimethyl-4-methoxypyridyl-2-methyl)amine,
PDP* = bis(3,5-dimethyl-4-methoxypyridyl-2-methyl)-(<i>S</i>,<i>S</i>)-2,2′-bipyrrolidine). Using very low temperatures,
−75 to −85 °C, the extremely unstable and reactive
iron–oxygen intermediates, directly reacting with olefins even
at −85 °C, have been detected for the first time. Their
EPR parameters (<i>g</i><sub>1</sub> = 2.070–2.071, <i>g</i><sub>2</sub> = 2.005–2.008, <i>g</i><sub>3</sub> = 1.956–1.960) were very similar to those of the known
oxoiron(V) complex [(TMC)Fe<sup>V</sup>O(NC(O)CH<sub>3</sub>)]<sup>+</sup> (<i>g</i><sub>1</sub> = 2.053, <i>g</i><sub>2</sub> = 2.010, <i>g</i><sub>3</sub> = 1.971, TMC
= 1,4,8,11-tetramethyl-1,4,8,11-tetraazacyclotetradecane). On the
basis of EPR and reactivity data, the detected intermediates were
assigned to the Fe<sup>V</sup>O active oxidizing species of
the catalyst systems studied
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