Search results for "organometallic"
showing 10 items of 370 documents
Inside a Shell—Organometallic Catalysis Inside Encapsulin Nanoreactors
2021
Abstract Compartmentalization of chemical reactions inside cells are a fundamental requirement for life. Encapsulins are self‐assembling protein‐based nanocompartments from the prokaryotic repertoire that present a highly attractive platform for intracellular compartmentalization of chemical reactions by design. Using single‐molecule Förster resonance energy transfer and 3D‐MINFLUX analysis, we analyze fluorescently labeled encapsulins on a single‐molecule basis. Furthermore, by equipping these capsules with a synthetic ruthenium catalyst via covalent attachment to a non‐native host protein, we are able to perform in vitro catalysis and go on to show that engineered encapsulins can be used …
Silicatein conjugation inside nanoconfined geometries through immobilized NTA–Ni(ii) chelates
2013
The chemical modification and bioconjugation processes inside confined geometries by His-tagged silicatein promote sensitive changes in the polarity and surface charge density that mainly contribute to the ionic current rectification properties of the single conical nanopores.
Polyoxometalate salts of cationic nitronyl nitroxide free radicals
2008
The cationic nitronyl nitroxide free radical of the N-methylpyridinium type p-MepyNN + has been combined with [Mo 8 0 26 ] 4- and Keggin [SiW 12 0 40 ] 4- polyanions to afford salts ( p-MepyNN) 4 [Mo 8 0 26 ] DMSO (DMSO = dimethylsulfoxide) (1) and (p-MepyNN)4[SiW 12 0 40 ] 6DMF (DMF = dimethylformamide) (2). Herein, their structural and magnetic properties are described.
Layered ferromagnets hosting tetraalkylammonium-substituted nitronyl nitroxide free radicals
2008
This paper describes the structural, magnetic and EPR properties of hybrid organic/inorganic magnets formed by anionic heterometallic oxalato-based layers and cationic nitronyl nitroxide (NN) free radicals of the tetraalkylammonium type. A series of compounds of formula nBu3NCH2NN[MCr(ox)3] (M = Mn (1), Ni (2), Zn (3)) has been prepared and studied by AC and DC magnetic susceptibility measurements and EPR spectroscopy. Magnetic order with critical temperatures ranging from 5 K to 15 K was confirmed. EPR measurements show that the organic spin carriers interact significantly with the inorganic network.
Half-sandwich molybdenum(III) compounds containing diazadiene ligands and their use in the controlled radical polymerization of styrene
2002
Abstract The reaction of CpMoCl2 with diazadiene ligands RNCHCHNR (R2dad) affords the corresponding paramagnetic complexes CpMoCl2(R2dad) (R=Ph, 1; p-Tol, 2; C6H3Pr2i-2,6, 3; and Pri, 4). All compounds have been characterized by EPR spectroscopy and have been investigated by cyclic voltammetry. They display one-electron oxidation and reduction processes, these being reversible or irreversible depending on the nature of R. The irreversibility of the reduction wave is due to a chemical follow-up process which consists of chloride loss from the reduced product. This phenomenon is suppressed in the presence of excess chloride in solution. An X-ray structure of 3 verifies the mononuclear na…
Stimulated-echo NMR spectroscopy of 9Be and 7Li in solids: method and application to ion conductors.
2002
The generation of pure quadrupolar stimulated-echo spectra is successfully demonstrated for the spin-3/2 probe 9Be in a single crystal of triglycine fluoberyllate. This solid exhibits a paraelectric-to-ferroelectric phase transition. From experiments carried out for various mixing times no indications for a slow soft mode could be detected in this crystal. Then ion conducting lithium metal phosphates were studied using 7Li, another spin-3/2 probe which allows for a non-selective excitation of the entire NMR spectrum. In the indium and the scandium phosphates ultra-slow Li hopping processes could be detected directly via the stimulated-echo technique in a time range of up to four orders of m…
Bridging vs. Chelating Coordination Modes of Vinylsilanes in CuIπ-Complexes: Structure and Stability
2013
Two new copper(I) olefin complexes, [Cu6Cl6(MTrVS)2] (1) and [Cu2Cl2(DMVSP)2] (2), of tridentate bridging methyltrivinylsilane (MTrVS) and bidentate chelating 2-[dimethyl(vinyl)silyl]pyridine (DMVSP) have been synthesized and characterized by single-crystal X-ray structure analysis, IR and 1H NMR spectroscopy. It has been shown that using the alkenylsilanes with required electronic properties, molecular symmetry and conformational flexibility, it is possible to control the formation of optimal copper(I) halide oligomers. The obtained results, together with relevant literature data, also illustrate how the coordination mode of vinylsilanes is related to Cu–(C=C) bond strengthening and, conse…
Efficient deep-red light-emitting electrochemical cells based on a perylenediimide-iridium-complex dyad
2009
A two-layer light-emitting electrochemical cell device based on a new perylenediimide-iridium-complex dyad is presented emitting in the deep-red region with high external quantum efficiencies (3.27%). Costa Riquelme, Ruben Dario, Ruben.Costa@uv.es ; Orti Guillen, Enrique, Enrique.Orti@uv.es ; Bolink, Henk, Henk.Bolink@uv.es ; Gierschner, Johannes, Johannes.Gierschner@uv.es
Carbon–Phosphorus Coupling from C^N Cyclometalated Au III Complexes
2020
Abstract With the aim of exploiting new organometallic species for cross‐coupling reactions, we report here on the AuIII‐mediated Caryl−P bond formation occurring upon reaction of C^N cyclometalated AuIII complexes with phosphines. The [Au(C^N)Cl2] complex 1 featuring the bidentate 2‐benzoylpyridine (CCON) scaffold was found to react with PTA (1,3,5‐triaza‐7‐phosphaadamantane) under mild conditions, including in water, to afford the corresponding phosphonium 5 through C−P reductive elimination. A mechanism is proposed for the title reaction based on in situ 31P{1H} NMR and HR‐ESI‐MS analyses combined with DFT calculations. The C−P coupling has been generalized to other C^N cyclometalated Au…
Toxic Effects of Organometallic Compounds towards Marine Biota
2002
Organometallic derivatives are compounds containing a direct σ or π carbon metal linkage. Furthermore, the concept of the metallic atom must be extended to all the elements that are less negative than the carbon atom. As a consequence, taking into account all elements that are less negative than carbon and the number of existing organic compounds, it is possible to synthesize millions of organometallic derivatives. Several of these are extensively used in organic syntheses; others may find application in agriculture and in many other fields as pesticides, fire retardants, wood preservatives, antifouling agents, etc. In general, the organic derivatives of the metals are more toxic than the p…