Showing papers on "Ferrocene published in 1989"
TL;DR: Both ferrocene-mediated and hydrogen peroxide-detecting amperometric glucose sensors with a high density of covalently-linked enzyme have an operating stability in vitro which may render them suitable for clinical use as, for example, an overnight hypoglycaemia alarm.
143 citations
TL;DR: In this paper, 1,1′-Bis(diphenylphosphino)ferrocene (dppf) metal dichlorides (metal = Co, Ni, Pd, Pt, Zn, Cd, and Hg) are examined as a class of related complexes.
130 citations
76 citations
TL;DR: In this article, the voltammetric oxidation of ferrocene has been examined with microdisk electrodes in supercritical CO{sub 2} containing small-amounts of added water.
Abstract: The voltammetric oxidation of ferrocene has been examined with microdisk electrodes in supercritical CO{sub 2} containing small-amounts of added water. Voltammograms obtained under these conditions indicate a high rate of diffusion for ferrocene but exhibit considerable ohmic drop. The ohmic distortion of the voltammograms is reduced by the addition of tetrahexylammonium hexafluorophosphate ((THA)PF{sub 6}) to the cell. However, when large amounts of (THA)PF{sub 6} are added to the cell, visual inspection indicates a two-phase system under the conditions used. Near-infrared spectra show that the upper phase is supercritical CO{sub 2} and the lower phase is liquid (THA)PF{sub 6}. This result is obtained at a temperature that is 64{degree}C below the melting point of pure (THA)PF{sub 6} at atmospheric pressure. Ferrocene is found to have a much lower diffusion coefficient in the molten salt. However, the limiting current recorded in the molten salt is not attenuated relative to that in the upper phase, because ferrocene preferentially dissolves in the molten salt. It is shown that the molten salt, when added in small amounts to the cell, acts as an electrode-surface modifier that promotes ionic conductivity and allows the oxidation of ferrocene extracted from the supercritical CO{sub 2}. This occurs even whenmore » the electrode is placed in the upper CO{sub 2} phase.« less
62 citations
TL;DR: In this article, a new ferrocene derivative was synthesized by reacting hydroxymethylferrocene with anthracene-9-carboxylic acid.
Abstract: A new ferrocene derivative was synthesized by reacting hydroxymethylferrocene with anthracene-9-carboxylic acid. This new compound strongly adsorbs on the surface of a graphite electrode to form a stable chemically modified electrode. The formal potential of the adsorbed ferrocene derivative was +340 mV versus SCE in solutions containing 0.1 M perchlorate. When adsorbed, the ferrocene derivative mediates the charge transfer between the electrode and glucose oxidase.
60 citations
52 citations
47 citations
TL;DR: A chiral ferrocenylphosphine ligand with C2-symmetric structure and a functional group on the side chain was prepared by ortho-lithiation and phosphination of 1,1′-bis[1-(N,N-dimethylamino)ethyl]ferrocene followed by optical resolution of the ditartrate salts and was found to be effective for palladium-catalysed asymmetric cross-coupling of 1-phenylethylzinc chloride with vinyl bromide giving 3-phenylbut
Abstract: A new chiral ferrocenylphosphine ligand, which has C2-symmetric structure and a functional group on the side chain, was prepared by ortho-lithiation and phosphination of 1,1′-bis[1-(N,N-dimethylamino)ethyl]ferrocene followed by optical resolution of the ditartrate salts and was found to be effective for palladium-catalysed asymmetric cross-coupling of 1-phenylethylzinc chloride with vinyl bromide giving 3-phenylbut-1-ene of over 90% e.e.
45 citations
TL;DR: A chiral ferrocenylphosphine ligand, 2,2′-bis[1-N, N-dimethylamino)ethyl]-1,1-bis(diphenylphophosphino)ferrocene (2), which has C2 symmetry and a functional group on the side chain, was prepared by ortho-lithiation and phosphination of 1,1′-bi[1,N,N-dimethyl]ethyl] as discussed by the authors followed by optical resolution; recrystallization of the diammonium
44 citations
41 citations
TL;DR: In this paper, the cyclic voltammetry of methyl viologen (MV 2+ ), decamethylferrocene (DMFc), Os(bpy) 3 2+ (bpy = 2,2'-bipyridine) and ferrocene(Fc) was studied at high temperatures and pressures in a small cell (7.5 ml).
TL;DR: In this paper, 13C NMR and cyclic voltammetry (CV) data are reported for some ferrocene derivatives in which the ferrocenyl group is bonded to N And P.
TL;DR: A single-crystal X-ray diffraction study of 1,1′,3,3′-tetrakis(trimethylsilyl)ferrocene Fe[(1,3-SiMe 3 ) 2 -η 5 -C 5 H 3 ] 2 has revealed a conformation of C 2 symmetry in which the trimethyl silyl groups are arranged in a staggered fashion, with the five-membered rings nearly eclipsed as discussed by the authors.
TL;DR: The crystal and molecular structure of 1,l ′-bis(4′-pentyloxybiphenyl)ferrocene dicarboxylate ester (1) has been determined by X-ray diffraction at 295 and 160K as mentioned in this paper.
Abstract: The crystal and molecular structure of 1,l ′-bis(4′-pentyloxybiphenyl)ferrocene dicarboxylate ester (1) has been determined by X-ray diffraction at 295 and 160K. The molecule is found to exist at both temperatures in an extended S geometry. The carboxyl groups are essentially coplanar with the cyclopentadienyl rings but almost perpendicular to the attached phenyl ring. Low angle X-ray diffraction of three diesters in the smectic phases were also studied. The results were not very definitive because of the lack of thermal stability for the monotropic phase behaviour. Nevertheless, the layer spacing of about 47 A for one of the compounds at 409K is consistent with the extended S shape conformation.
TL;DR: In this paper, iron-containing aromatic copolyesters were synthesized from 1,1′-bis-(chlorocarbonyl)ferrocene, terephthaloyl chloride, isophthaloyls chloride and methylhydroquinone.
Abstract: Iron-containing aromatic copolyesters were synthesized from 1,1′-bis-(chlorocarbonyl)ferrocene, terephthaloyl chloride, isophthaloyl chloride and methylhydroquinone. The copolymers obtained were characterized for their liquid crystalline properties by a variety of methods, and all of the copolyesters synthesized were nematic.
TL;DR: Siloxane polymers containing ferrocene and 1,1′-dimethylferrocene as pendants have been synthesized and characterised; cyclic voltammetry studies using electrodes modified with these polymers showed that the electrochemical properties of ferrocenes and 1 1/dimethyelferrocenes were maintained.
Abstract: Siloxane polymers containing ferrocene and 1,1′-dimethylferrocene as pendants have been synthesised and characterised; cyclic voltammetry studies using electrodes modified with these polymers showed that the electrochemical properties of ferrocene and 1,1′-dimethylferrocene were maintained.
TL;DR: In this paper, a series of Pd II complexes containing various Group V-donors were reduced with diisobutylaluminum hydride and the products screened as potential catalysts for the coupling of representative vinyl- and aryl-trifluoromethanesulfonate substrates to the reformatsky reagent BrZnCH(CH 3 )(COO t C 4 H 9 ).
TL;DR: In this article, the use of bis(diphenylphosphino)ferrocene as a ligand of palladium brought about the stereoselective coupling of β-bromo esters and 1-alkenylboronates.
Abstract: (2E,4E)-, (2Z,4E)-, and (2E,4Z)-2,4-Alkadienoates can be synthesized in high yields by the cross-coupling of ethyl (E)-3-bromoacrylate, methyl (E)-3-bromo-2-methylpropenoate, ethyl (Z)-3-bromocrotonate,1-bromo-2-(ethoxycarbonyl)cyclohexene, and 4-bromocoumarin with 2-[(E)-1-alkenyl]-1,3,2-benzodioxaboroles or diisopropyl (Z)-1-hexenylboronate in the presence of 3 mol% of Pd(OAc)2, 6 mol% of PPh3, and 2 equivalents of Na2CO3 or K2CO3 in alcoholic solvents while retaining the original configuration of the double bonds in β-bromo esters and 1-alkenylboronates. Although the coupling reaction with 1-hexenylboronate with (Z)-3-bromoacrylate gave a mixture of ethyl (2Z,4E)- and (2E,4E)-nonadienoates in a ratio of 63 : 37, it was found that the use of bis(diphenylphosphino)ferrocene as a ligand of palladium brought about the stereoselective coupling under mild conditions.
TL;DR: In this paper, the gas phase ionization energies of 11 ferrocene derivatives have been measured by He(I) photoelectron spectroscopy and compared with the electrode oxidation potentials in aprotic solvents.
Abstract: The gas-phase ionization energies of 11 ferrocene derivatives have been measured by He(I) photoelectron spectroscopy and compared with the electrode oxidation potentials in aprotic solvents. The first four ionization energies and the oxidation potentials of these compounds change linearly with the Hammett substitution constants. Linear correlations with slopes ca. 0.7 have been obtained between the first adiabatic ionization energies and the oxidation potentials in several aprotic solvents. This result indicates that the solvent effect on Fc/Fc+ couples changes proportionally with the gas-phase ionization energies.
TL;DR: In this article, the coordination of alkaline-earth and lanthanide metal cations by a cryptand containing the ferrocene unit has been examined by cyclic voltammetry; the data were used to deduce values of K2 for the association of oxidised cryptand (1+) with this range of metalcations and a linear correlation between ln K2 and the ratio of ionic radius/ionic charge is reported.
Abstract: The co-ordination of alkaline-earth and lanthanide metal cations by a cryptand containing the ferrocene unit has been examined by cyclic voltammetry; the data are used to deduce values of K2 for the association of oxidised cryptand (1+) with this range of metal cations and a linear correlation between ln K2 and the ratio of ionic radius/ionic charge is reported.
TL;DR: In this article, the outer-sphere electron transfer from ferrocene derivatives to metalloporphyrins (MTPP+), followed by acid-catalyzed reduction of dioxygen by MTPP in the presence of perchloric acid in acetonitrile.
Abstract: Metalloporphyrin-catalyzed reduction of dioxygen by ferrocene derivatives occurs efficiently via outer-sphere electron transfer from ferrocene derivatives to metalloporphyrins (MTPP+), followed by acid-catalyzed reduction of dioxygen by MTPP in the presence of perchloric acid in acetonitrile.
TL;DR: In this article, the authors studied the intracavity chemistry of (CpFe(CO){sub 2} ) and ferrocene in different acid forms of zeolite Y has been studied with EXAFS, in situ FTIR, and TPD-MS spectroscopies.
Abstract: The intracavity chemistry of (CpFe(CO){sub 2}){sub 2} (1) and ferrocene in different acid forms of zeolite Y has been studied with EXAFS, in situ FTIR, and TPD-MS spectroscopies. Depending on the stoichiometry of zeolite protons vs the amount of starting complex 1, the complex is either oxidatively cleaved into CpFe(CO){sub 3}{sup +} (2) and CpFe{sup +} coordinated to the zeolite, or protonated to form dimeric (CpFe(CO){sub 2}){sub 2}H{sub +} (3). It is shown that the stability of all complexes is influenced by the intracavity concentration of the zeolite-bridged hydroxyl groups. The cationic monomer 2 is stable up to 500 K in the highly acidic zeolite host, whereas the protonated dimer decomposes above 400 K. At higher temperatures, all carbonyl ligands are split off from the iron complexes, and the remaining dominant fragments are identified as CpFe(OZ){sub n} (n = 2-3), bonded to the zeolite host structure via oxygen coordination. Similar fragments are formed upon thermal decomposition of ferrocene in the zeolite.
10 Nov 1989-Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment
TL;DR: In this article, the authors investigated the possibility of using organometallic photocathodes (ferrocene, diethyl ferrocene (DF), cyclopentadienyl-iron-hexamethyl-benzene) in gaseous detectors and found that condensed layers of these substances could increase the sensitivity of metallic cathodes to VUV radiation by several orders of magnitude.
Abstract: We have investigated the possibility of using organometallic photocathodes (ferrocene, diethyl ferrocene, ethyl ferrocene, and cyclopentadienyl-iron-hexamethyl-benzene) in gaseous detectors. We found that condensed layers of these substances could increase the sensitivity of metallic cathodes to VUV radiation by several orders of magnitude. The best choice seems to be ethyl ferrocene, which can be used as the photosensitive element in the vapour phase as well as in condensed and absorbed layers. A parallel-plate chamber with this photocathode, operated at atmospheric pressure, combines a rather good time resolution (∼ 10 ns or better) with a sensitivity better than 1% for wavelengths shorter than 230 nm.
TL;DR: In this article, photoinduced electron transfer kinetics in Langmuir-Blodgett (LB) films were studied in connection with photoelectric conversion devices, where four kinds of amphiphilic ferrocene derivatives as electron donors with different standard redox potentials and with the same alkyl chain spacer were newly synthesized.
TL;DR: In this paper, it was suggested that the chemiluminescent emission of a few of the prominent atomic iron lines in the ultraviolet (the less sensitive response from the stoichiometric hydrogen-air flame is spectrally more complex).
TL;DR: In this article, 1H NMR complexation studies (CD3CN) showed that none of the metallocene calix[4]arene receptors form solution host-guest complexes with t-butylamine and benzylamine.
TL;DR: In this article, 1,1,1′-Bis(methoxymethyl)ferrocene undergoes stereoselective directed dilithiation in the presence of t -butyllithium evidence is presented to establish the stereochemistry of the products.
CERN1
01 May 1989-Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment
TL;DR: In this article, the properties of an organometallic compound, ethyl ferrocene (EF), which was proposed to use as the photosensitive element in gaseous detectors, both in the gas (vapour) phase and, in condensed or adsorbed layers, as photocathodes.
Abstract: We have investigated the properties of an organometallic compound, ethyl ferrocene (EF), which we propose to use as the photosensitive element in gaseous detectors, both in the gas (vapour) phase and, in condensed or adsorbed layers, as photocathodes. The big advantage of EF is that it is easy to handle, as it is not reactive to oxygen. The sensitivity for the detection of BaF2 fast emission was measured with EF vapour and was found to be lower by a factor of close to 1.5 compared with TMAE vapour measured under the condition of full light absorption. Adsorbed or condensed layers of EF used as photocathodes in a gaseous detector achieved an efficiency that was lower by a factor of 4 to 10, depending on the experimental conditions.