Search results for "Single"
showing 10 items of 4920 documents
Reversible solvatomagnetic switching in a single-ion magnet from an entatic state
2016
We have developed a new strategy for the design and synthesis of multifunctional molecular materials showing reversible magnetic and optical switching.
Synthesis, structure and properties of new heterometallic octanuclear Li2Na2Cu4 and decanuclear Li2Zn8 complexes
2019
Abstract A carboxylate containing polydentate ligand in combination with exogeneous succinate (suc) has been used to stabilize heterometallic octanuclear [Li2Na2Cu4(cpdp)2(suc)2(CH3OH)2(H2O)4]Cl2·6H2O (1) and decanuclear Na(H3O)2[Li2Zn8(cpdp)4(suc)2(H2O)4]Cl2Br3·6MeOH·19H2O (2) complexes. The reaction of ligand H3cpdp (H3cpdp = N,N'-bis[2-carboxybenzomethyl]-N,N'-bis[2-pyridylmethyl]-1,3-diaminopropan-2-ol) with stoichiometric amounts of CuCl2/sodium succinate, and ZnCl2/sodium succinate, allowed isolation of complexes 1 and 2, respectively. Analyses of single crystal X-ray structures indicate that complex 1 is capped by two [Cu2(cpdp)]+ molecular building units and two succinate linkers, w…
Microwave assisted synthesis and solid-state characterization of lithocholyl amides of isomeric aminopyridines
2011
Microwave (MW) assisted synthesis and solid state structural characterizations of novel lithocholyl amides of 2-, 3-, and 4-aminopyridine are reported. It is shown that the MW technique is a proper method in the preparation of N-lithocholyl amides of isomeric aminopyridines. It offers many advantages compared to conventional heating. The molecular and crystal structures as well as the polymorphic and hydrated forms of prepared conjugates with their thermodynamic stabilities have been characterized by means of high resolution liquid- and solid-state NMR spectroscopy, single crystal and powder X-ray diffraction, and thermogravimetric analysis. Owing to the many biological functions of bile ac…
Solvent Modulated Assembly of Two Ni(II) Complexes: Syntheses, Structures and Magnetic Properties
2016
A dinuclear [Ni2(L)2(DMSO)2(MeOH)2] (1) and a tetra-nuclear [Ni4(L)4(DMF)2(H2O)2].DMF (2) Ni(II) complexes have been prepared by treating nickel nitrate hexahydrate with the Schiff base ligand H2L (H2L=(E)-2-(2-hydroxybenzyliden)amino-4-nitrophenol) in a one-pot reaction. Complex 1 was obtained after recrystallization of the precipitate from the reaction with a 1:1:1 mixture of DMSO/CH2Cl2/MeOH. In contrast, the tetrameric complex 2 was obtained after slow evaporation of the filtrate. Both complexes were characterized by analytical, thermogravimetric, optical and magnetic techniques. The solid state molecular structures of 1 and 2 were determined by single crystal X-ray crystallography. Com…
Luminescence Dating of Fluvial Deposits in the Rock Shelter of Cueva Antón, Spain
2015
Abstract The fluvial sediments at Cueva Antón, a Middle Palaeolithic rock shelter located in the valley of the River Mula (Southeast Spain), produced abundant lithic assemblages of Mousterian affinities. Radiocarbon dates are available for the upper part of the archaeological succession, while for the middle to lower parts chronometric data have been missing. Here we present luminescence dating results for these parts of the succession. Quartz OSL on small aliquots and single grain measurements yield ages ranging from 69 ± 7 ka to 82 ± 8 ka with a weighted mean of 72 ± 4 ka for sub-complexes AS2 to AS5. Equivalent dose estimates from large aliquots were highest and inconsistent with those f…
Structural basis and effect of copper(II) complexes with 4-oxo-thiazolidine ligands on DNA binding and nuclease activity
2020
Abstract Seven novel Copper(II) complexes, namely [Cu(Am4DHotaz)(H2O)2](ClO4) (1), [Cu(Am4DHotaz)(NO3)(MeOH)]·H2O (2), [Cu(Am4Motaz)2(H2O)](ClO4)2·0.83H2O (3), [Cu(Am4Motaz)2(NO3)]NO3·MeOH (4), [Cu(Am4Eotaz)2(NO3)]3(NO3)3·2H2O (5), [Cu(Am4Eotaz)2(ClO4)](ClO4) (6) and [Cu(Am4Eotaz)(ClO4)(H2O)](ClO4) (6a) (HAm4DHotaz = N′-(4-oxothiazolidin-2-ylidene)pyridine-2-carbohydrazonamide, Am4Motaz = N′-(3-methyl-4-oxothiazolidin-2-ylidene)pyridine-2-carbohydrazonamide and Am4Eotaz = N′-(3-ethyl-4-oxothiazolidin-2-ylidene)pyridine-2-carbohydrazonamide), have been successfully synthesized and characterized by several physicochemical techniques and, for 1–6 complexes, single crystal X-ray diffraction. Ha…
Polycatenane systems from Co(II) and trans-1,2-bis(4-pyridyl)ethene (bpe). Synthesis and structure of Co(bpe)2(NCS)2·CH3OH, [Co(bpe)2(H2O)2](ClO4)2·2…
2001
Three new compounds of formulae Co(bpe)2(NCS)2·CH3OH, 1, [Co(bpe)2(H2O)2](ClO4)2·2CH3OH, 2 and [Co(bpe)2(H2O)2(CH3OH)2](ClO4)2·bpe·H2O, 3, [bpe = trans-1,2-bis(4-pyridyl)ethene] have been synthesised and characterised by single crystal X-ray diffraction. The metal environment in 1–3 is distorted octahedral. Compound 1 is a polycatenane. Its structure consists of parallel layers containing Co2+ ions linked by bpe ligands, the Co···Co distance through the bpe bridge being 13.65(3) A. Each metal ion, in a layer, defines the edges of a rhombus. Two thiocyanate groups trans-coordinated to the metal atoms are perpendicular to the sheets. Each sheet has an infinite number of perpendicular sheets …
Spectral and structural insights of copper reduction pathways in the system of CuX2-R2S (X=Cl, Br; R=allyl, n-propyl)
2021
Abstract We have explored the behaviour of Cu(II)/Cu(I) redox couple in the system CuX2-R2S, X = Cl, Br; R = allyl, n-propyl, under anhydrous and anaerobic conditions, thus simulating the reduction half cycle in the copper catalyzed oxidation of thioethers. In doing so, the Cl−Br substitution was critical for tuning the reduction potentials, while the replacement of propyl group by allyl group supported the trapping of oxidation by-product, halogen molecules. It was therefore possible to use the spectrophotometric titration, thereby providing information on the distribution of complex species in acetonitrile solution. The study showed that the trinuclear mixed−valence copper (I-II-II) aggre…
A simple method for preoperative assessment of the best fitting electrode length in single lead VDD pacing.
1996
For single lead VDD pacing, electrodes with various distances between the lead tip and the floating atrial dipole (AV distance) are available. Using different AV distances allows positioning of the atrial dipole in the mid- to high right atrium, regardless of the size of the right heart. In this position, reliable atrial sensing and rejection of ventricular far-field potentials can be expected. A simple test for the preoperative assessment of the best fitting AV distance in the individual patient was tested. We studied 24 consecutive patients prior to implantation of a VDD pacemaker. With the patient in supine position, a test electrode with an AV distance of 13 cm was taped onto the thorax…
A critical evaluation of caplacizumab for the treatment of acquired thrombotic thrombocytopenic purpura
2020
Introduction: Acquired thrombotic thrombocytopenic purpura (aTTP) is a thrombotic microangiopathy caused by inhibitory autoantibodies against ADAMTS13 protein. Until recently, the combination of plasma exchange (PEX) and immunosuppression has been the standard front-line treatment in this disorder. However, aTTP-related mortality, refractoriness, and relapse are still a matter of concern. Areas covered: The better understanding of the pathophysiological mechanisms of aTTP has allowed substantial improvements in the diagnosis and treatment of this disease. Recently, the novel anti-VWF nanobody caplacizumab has been approved for acute episodes of aTTP. Caplacizumab is capable to block the adh…