Search results for "Thio-"
showing 10 items of 52 documents
NMR, potentiometric and ESI-MS combined studies on the zinc(II) magnesium(II) and calcium(II) complexation by (morpholin-1-yl)methane-1,1-diphosphoni…
2012
Abstract The crystal structures of the two derivatives of aminomethane-1,1-diphosphonic acid with morpholinyl- (1) and thiomorpholinyl- (2) side chains were determined by single crystal X-ray diffraction and discussed with respect to molecular geometry and solid state organization. The protonation equilibria, solution behavior and complex-formation equilibria in solutions of 1 and 2 with the Zn(II), Mg(II) and Ca(II) ions were studied by means of NMR, pH-potentiometry and ESI-MS methods. As the p K ( NH + ) protonation constants of 1 and 2 are high (11.65 and 11.91, respectively) two different approaches were used to evaluate the pH-potentiometric data. The first approach disregarded the pr…
Di- and Tetrairon(III) μ-Oxido Complexes of an N3S-Donor Ligand: Catalyst Precursors for Alkene Oxidations
2019
The new di- and tetranuclear Fe(III) μ-oxido complexes [Fe 4 (μ-O) 4 (PTEBIA) 4 ](CF 3 SO 3 ) 4 (CH 3 CN) 2 ] (1a), [Fe 2 (μ-O)Cl 2 (PTEBIA) 2 ](CF 3 SO 3 ) 2 (1b), and [Fe 2 (μ-O)(HCOO) 2 (PTEBIA) 2 ](ClO 4 ) 2 (MeOH) (2) were prepared from the sulfur-containing ligand (2-((2,4-dimethylphenyl)thio)-N,N-bis ((1-methyl-benzimidazol-2-yl)methyl)ethanamine (PTEBIA). The tetrairon complex 1a features four μ-oxido bridges, while in dinuclear 1b, the sulfur moiety of the ligand occupies one of the six coordination sites of each Fe(III) ion with a long Fe-S distance of 2.814(6) A. In 2, two Fe(III) centers are bridged by one oxido and two formate units, the latter likely formed by methanol oxidati…
First Cobalt(II) Spin Crossover Compound with N4S2-Donorset
2020
Herein we report the synthesis and characterization of a novel bis-tridentate 1,3,4-thiadiazole ligand (L = 2,5-bis[(2-pyridylmethyl)thio]methyl-1,3,4-thiadiazole). Two new mononuclear complexes of the type [MII(L)2](ClO4)2 (with M = FeII (C1) and CoII (C2)) have been synthesized, containing the new ligand (L). In both complexes the metal centers are coordinated by an N4S2-donorset and each of the two ligands is donating to the metal ion with just one of the tridentate pockets. The iron(II) complex (C1) is in the low spin [LS] state below room temperature and shows an increase in the magnetic moment only above 300 K. In contrast, the cobalt(II) complex (C2) shows a gradual spin crossover (S…
Pyridinium bis(pyridine-κN)tetrakis(thiocyanato-κN)ferrate(III) -pyrazine-2-carbonitrile-pyridine (1/4/1)
2013
In the title compound, (C5H6N)[Fe(NCS)4(C5H5N)2]·4C5H3N3·C5H5N, the Fe(III) ion is located on an inversion centre and is six-coordinated by four N atoms of the thio-cyanate ligands and two pyridine N atoms in a trans arrangement, forming a slightly distorted octa-hedral geometry. A half-occupied H atom attached to a pyridinium cation forms an N-H⋯N hydrogen bond with a centrosymmetrically-related pyridine unit. Four pyrazine-2-carbo-nitrile mol-ecules crystallize per complex anion. In the crystal, π-π stacking inter-actions are present [centroid-centroid distances = 3.6220 (9), 3.6930 (9), 3.5532 (9), 3.5803 (9) and 3.5458 (8) Å].
Pyridinium bis(pyridine-κN)tetrakis(thiocyanato-κN)ferrate(III)
2013
In the title compound, (C5H6N)[Fe(NCS)4(C5H5N)2], the Fe(III) ion is coordinated by four thio-cyanate N atoms and two pyridine N atoms in a trans arrangement, forming an FeN6 polyhedron with a slightly distorted octa-hedral geometry. Charge balance is achieved by one pyridinium cation bound to the complex anion via N-H⋯S hydrogen bonding. The asymmetric unit consists of one Fe(III) cation, four thio-cyanate anions, two coordinated pyridine mol-ecules and one pyridinium cation. The structure exhibits π-π inter-actions between pyridine rings [centroid-centroid distances = 3.7267 (2), 3.7811 (2) and 3.8924 (2) Å]. The N atom and a neighboring C atom of the pyridinium cation are statistically d…
A Versatile Synthesis of Fluorinated Uracils in Solution and on Solid-Phase.
2004
[reaction: see text] An efficient and convenient two-step synthesis of new fluorinated uracils is described. The first step involves the condensation of an ester enolate with a fluorinated nitrile to furnish fluorinated beta-enamino esters. In turn, these compounds react with organic isocyanates or isothiocyanates to give C-6 fluorinated uracils or thiouracils, respectively, in excellent yields. This synthesis has been successfully adapted to solid-phase conditions with high diversity, thereby facilitating the creation of small (thio)uracil libraries.
Sulfur’s role in the flame retardancy of thio-ether–linked hyperbranched polyphosphoesters in epoxy resins
2020
Abstract Hyperbranched polyphosphoesters are promising multifunctional flame retardants for epoxy resins. These polymers were prepared via thiol-ene polyaddition reactions. While key chemical transformations and modes of actions were elucidated, the role of sulfur in the chemical composition remains an open question. In this study, the FR-performance of a series of phosphorus-based flame retardant additives with and without sulfur (thio-ethers or sulfones) in their structure are compared. The successful synthesis of thio-ether or sulfone-containing variants is described and verified by 1H and 31P NMR, also FTIR and MALDI-TOF. A decomposition process is proposed from pyrolytic evolved gas an…
Zwitterionic codeine-derived methacrylate monoliths for enantioselective capillary electrochromatography of chiral acids and chiral bases
2018
Thiol-ene click reaction of N-acetyl-L-cysteine methyl ester to codeine, followed by reaction with allyl isocyanate and hydrolysis to the corresponding zwitterionic chiral selector and its subsequent bonding to the surface of a methacrylate monolith provided a new chiral capillary column for enantiomer separation of chiral acids and chiral bases. First, the epoxy groups of a poly(glycidyl methacrylate-co-ethylene dimethacrylate) monolith were converted into amine residues, followed by reaction with allylglycidyl ether. In this way, a spacer arm was bonded to the surface before coating and cross-linking poly(3-mercaptopropyl methylsiloxane) (PMPMS) via radical addition (thiol-ene click react…
CCDC 820753: Experimental Crystal Structure Determination
2011
Related Article: F.Riobe, F.Piron, C.Rethore, A.M.Madalan, C.J.Gomez-Garcia, J.Lacour, J.D.Wallis, N.Avarvari|2011|New J.Chem.|35|2279|doi:10.1039/c1nj20310j
CCDC 682377: Experimental Crystal Structure Determination
2009
Related Article: R.Kinghat, A.Khatyr, G.Schmitt, M.Knorr, M.M.Kubicki, E.Vigier, F.Villafane|2008|Inorg.Chem.Commun.|11|1060|doi:10.1016/j.inoche.2008.05.022