Search results for "Chloromethane"
showing 10 items of 692 documents
Transition metal binding properties of the redox-active 1,4,7,10,13,16-hexa(ferrocenylmethyl)-1,4,7,10,13,16-hexaazacyclooctadecane and its electroch…
1999
Abstract Solution studies to elucidate the coordination behaviour and the electrochemical response of the ferrocene-functionalized polyazamacrocycle 1,4,7,10,13,16-hexa(ferrocenylmethyl)-1,4,7,10,13,16-hexaazacyclooctadecane (L1) by potentiometric methods and electrochemical techniques have been carried out. Potentiometric methods in the presence of Cd2+, Hg2+, Pb2+ and Zn2+ were carried out in 1,4-dioxane/water (70:30 v/v, 25°C, 0.1 mol dm−3 KNO3). Electrochemical studies were carried out in acetonitrile/dichloromethane (50:50 v/v, 25°C, 0.1 mol dm−3 TBAClO4) in the presence of transition metal ions and anions.
OH–π and halogen–π interactions as driving forces in the crystal organisations of tri-bromo and tri-iodo trityl alcohols
2008
The trityl alcohols bearing three bromine or three iodine atoms at the para-positions of the aromatic units, have been known for more than a hundred years. In our case these compounds have been synthesized in one-pot sequence starting from the 1,4-dihalogenobenzenes via mono-lithiation and the successive reaction with diethylcarbonate. The compounds have been crystallized from different solvent mixtures leading to one structure of bromo- (A) and three structures of iodo trityl alcohols (B–D). The inclusion of dichloromethane (C) or benzene (D) in the crystalline lattices has been observed. In all cases the OH–π and halogen–π (and in one case the halogen-halogen and CH-O weak) contacts play …
Asymmetric Hydrogenation of Nonfunctionalized Olefins in Propylene Carbonate—Kinetic or Thermodynamic Control?
2011
Iridium-catalyzed hydrogenations of nonfunctionalized olefins in propylene carbonate as the solvent allow efficient catalysis with much higher enantioselectivities in comparison with dichloromethane which is usually employed for these reactions. Experimental and computational studies of the hydrogenation of 1-methylene-1,2,3,4-tetrahydronaphthalene have been performed to understand the limitation for this reaction.
Structural and spectroscopic study of the Br2...3-Br-pyridine complex by DFT calculations.
2007
Abstract The structure and the Raman vibrational spectrum of the complex Br 2 ⋯3-Br-pyridine are determined by DFT calculations using different parametrizations. The calculations are performed taking into account the effects of the dichloromethane as solvent by the CPCM method. A value of 39 kJ mol −1 for the formation enthalpy and of 1 kJ mol −1 for the formation free energy at room temperature in presence of the solvent is found. The predicted Raman spectrum is compared with the experimental one and the essential features of the spectrum are well reproduced by the B3LYP parametrization. The intensity changes of the bands when going from the free moieties to the complex are also generally …
Baeyer−Villiger Oxidation with Potassium Peroxomonosulfate Supported on Acidic Silica Gel
2005
[reaction: see text] Potassium peroxomonosulfate deposited onto silica SiO2 x KHSO5 efficiently reacts with ketones in dichloromethane at room temperature to give the corresponding esters or lactones in quantitative yields. This method avoids hydrolysis of the reaction products. The Baeyer-Villiger reaction is catalyzed by potassium hydrogensulfate present in the supported reagent.
cis-[Bis(diphenylphosphino)ethane-κ2P,P′]dichlororuthenium(II) dichloromethane disolvate
2006
The title compound, cis-[RuCl2(C26H24P2)2]·2CH2Cl2, was obtained as an unexpected product from our attempts to prepare new ruthenium molecular wires using organic bridging ligands. Three solvates and a solvent-free structure of the isomeric complex with the chloride anions in a trans geometry have already been reported, while the cis isomer has been described only in solution studies prior to this work.
cis-Diazido[bis(diphenylphosphino)methane-κ2P,P′]ruthenium(II) dichloromethane 0.42-solvate
2006
Submitted by António Freitas (amsf@uma.pt) on 2019-06-13T13:44:22Z No. of bitstreams: 1 cis-Diazidobis(diphenylphosphino)methane-j2PP000ruthenium(II) dichloromethane 0.42-solvateJoãoRodrigues.pdf: 167616 bytes, checksum: 2ba0b7a76027be3eda26ce11d43fec66 (MD5) Made available in DSpace on 2019-06-13T13:44:22Z (GMT). No. of bitstreams: 1 cis-Diazidobis(diphenylphosphino)methane-j2PP000ruthenium(II) dichloromethane 0.42-solvateJoãoRodrigues.pdf: 167616 bytes, checksum: 2ba0b7a76027be3eda26ce11d43fec66 (MD5) Previous issue date: 2006 info:eu-repo/semantics/publishedVersion
Cd(II) and Cu(II) coordination polymers constructed from the expanded 1,4-bis(4-pyridyl)-2,3-diaza-1,3-butadiene ligand: conventional and ultrasound-…
2018
Shaabani, Behrouz/0000-0001-5576-4604; Kubicki, Maciej/0000-0001-7202-9169; Grzeskiewicz, Anita M./0000-0003-0377-2260 WOS: 000447971700041 A 3D open inorganic/organic framework, {[Cd(mu-L)(mu(3)-SO4)(H2O)]center dot H2O}(n) (1) [L = 1,4-bis(4-pyridyl)-2,3-diaza-1,3-butadiene] was synthesized by the reaction of CdSO4 center dot 8H(2)O with L. The treatment of Cu(NO3)(2)center dot 3H(2)O with the same N,N'-donor ligand in two different solvent mixtures, methanol/ dichloromethane (2) and methanol/ chloroform (3), afforded two new ladder-like coordination polymers of formula {[Cu(mu-L)(mu-NO3)(NO3)]center dot solv}(n) [solv = CH2Cl2 (2) and CHCl3 (3)]. The non-interpenetrated ladder motifs 2 a…
Simultaneous isolation of xanthomegnin, viomellein, rubrosulphin, viopurpurin, and brevianamide A by preparative HPLC.
1984
A method for the isolation of xanthomegnin, viomellein, rubrosulphin, viopurpurin, and brevianamide A from Penicillium viridicatum (DSM 2447) is described. After extraction, HPLC was performed with a preparative silicagel column, eluted with toluene / ethyl acetate / formic acid (27/9/1, v/v/v) and dichloromethane / acetic acid (9/1, v/v). The toxins were detected with a UV-monitor. It was possible to isolate them in an absolutely pure state. The described method is operationally simple and very efficient.
BEHAVIOUR OF GRAPHITIZED CARBON BLACK IN THE EXTRACTION OF POLAR NON-IONIC NITROGEN-CONTAINING PESTICIDES. A CHECKING OF HYPOTHESES
2000
Graphitized Carbon Black (GCB) extractive cartridges are evaluated for on-line coupling with a C8 analytical column to determine eleven carbamates and one carboximide pesticide from spiked deionized water at the 1.2 μg/L level. Several experiments were carried out to ascertain whether GCB saturation, pesticide degradation on the surface, existence of by-pass channels, mobility among the bulk cartridge, or strong retention on the surface interfere with the determination of pesticides. Problems in on-line CGB elution are partially solved by modifying the acetonitrile/water gradient to contain a front of 100% acetonitrile for a few seconds. Eluting the same GCB cartridges off-line with dichlor…