Citations Only: Recent submissions
Now showing items 761-780 of 990
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Reliability of standard rate constants for rapid electrochemical reactions
(The American Chemical Society: Analytical Chemistry, 1984-07)A method is outlined for testing the reliability of standard rate constants, k^s, for rapid electrode reactions evaluated by using electrochemical perturbation techniques. This entails monitoring the response of the apparent ... -
Reaction of atomic oxygen with hydrogen bromide
(The American Chemical Society: Journal of Physical Chemistry, 1973-04-26)The reaction of atomic oxygen with HBr was studied in a fast discharge flow system by monitoring epr spectra of O(3P2), Br(2P3/2), OH(2pi3/2), and H(2S1/2) at various reaction times. The experimental results were found to ... -
Photoetching and modification of organic polymer surfaces with vacuum UV radiation
(Elsevier: Polymer Degradation and Stability, 1993)Commercially available organic polymer films were treated with radiation from 6·7 × 104 Pa He and Ar plasmas that were made to rotate inside a graphite tube by the application of an auxiliary magnetic field. To investigate ... -
Intra- and inter-molecular photoexcitations in a cyano-substituted poly(p-phenylenevinylene)
(Elsevier: Chemical Physics, 1998-02-01)We report a study of time-resolved photoluminescence (PL) in a cyano-substituted poly(p-phenylenevinylene). We have investigated the effect of excitation and emission wavelength as well as solvent on the PL. We observe ... -
Temperature dependence of the reaction hydroperoxo (HO2) + hydroperoxo at low pressures
(The American Chemical Society: Journal of Physical Chemistry, 1986-02-13)The temperature dependence of the self-reaction of HO2, HO2 + HO2 -> H2O2 + O2 (k1) (1), was investigated by detecting HO2 with laser magnetic resonance in a low-pressure flow tube coated with halocarbon wax. Two independent ... -
Room-temperature rate constant for the hydroperoxo + hydroperoxo reaction at low pressures
(The American Chemical Society: The Journal of Physical Chemistry, 1984-05-10)The rate constant, k1, for the self-reaction of HO2, HO2 + HO2 --> H2O2 + O2, was investigated in a discharge-flow system at room temperature and low pressures (1-7 torr) of He carrier gas by laser magnetic resonance ... -
Aggregation quenching of luminescence in electroluminescent conjugated polymers
(The American Chemical Society: Macromolecules, 1999-04-08)We report measurements of photoluminescence from films of a soluble phenylenevinylene polymer that has prospective importance as the emissive material in light-emitting diodes. We show unambiguously that there is long-lived ... -
Surface composition and distribution of fluorine in plasma-fluorinated polyimide
(The American Vacuum Society: Journal of Vacuum Science and Technology A: Vacuum, Surfaces, and Films, 1988-05)Surface composition, fluorine distribution, and morphology were determined for polyimide films modified downstream from microwave plasmas containing CF4/O2. Complementary analytical techniques including x-ray photoelectron ... -
Acylhydrazones as M1/M3 selective muscarinic agonists
(Elsevier: Bioorganic and Medicinal Chemistry Letters, 1996-11-05)To improve receptor binding affinity and to investigate functional selectivity of 2,8-dimethyl-1-oxa-8- azaspiro[4.5]decan-3-one acetylhydrazone 2 at muscarinic receptor subtypes, a series of acylhydrazones A was synthesized. ... -
Electrochemical oxidation and reduction of methylene-bridged complexes of manganese, cobalt, and rhodium
(The American Chemical Society: Organometallics, 1987-08)The oxidation and reduction of a series of alkylidene-bridged dimetallic compounds containing Mn, Co, or Rh have been studied by electrochemical and spectroscopic techniques. Oxidation results in production of a cation ... -
Heterogeneous electron-transfer kinetics for some multiply bonded dirhenium complexes
(Elsevier: Journal of Electroanalytical Chemistry, 1985-12-10)Standard electrochemical rate constants kexob have been measured for the two sequential one-electron oxidations of triply-bonded dirhenium(II) complexes Re2X4(PR3)4, where X = Cl or Br, and PR3 = a monodentate tertiary ... -
Unusual oxidative behavior of (.eta.5-C5R5)M(CO)2 (R = H, CH3; M = Rh, Co) complexes at mercury and platinum electrodes
(The American Chemical Society: Inorganic Chemistry, 1987-06-17)The electrochemical oxidative behavior of a series of cyclopentadienyl and pentamethylcyclopentadienyl carbonyl complexes of rhodium and cobalt is described. The voltammetric, polarographic, and coulometric data from the ... -
Use of poly(ester-sulfonic acid) film-coated electrodes as amperometric detectors in flow injection analysis
(Elsevier: Talanta, 1995-12)Within the past several years significant advances have been made towards the development and incorporation of chemically modified electrodes as selective detectors for high performance liquid chromatography and flow ... -
Adsorption of hydrogen on carbon single-walled nanotubes as measured by the volumetric technique
(Materials Research Society Proceedings: Symposium A: Nanotubes and Related Materials, 2000)We report on hydrogen adsorption onto carbon single-walled nanotube (SWNT) material as measured by the volumetric technique. This method determines the amount adsorbed by monitoring the pressure in a known volume at a known ... -
Solvent effects on the kinetics of simple electrochemical reactions. Further examination of metal ethylenediamine and ammine redox couples.
(Elsevier: Journal of Electroanalytical Chemistry, 1985-09-10)The dependence of the kinetics of Co(en)33+/2+ exchange (en=ethylenediamine) at mercury electrodes upon the nature of the solvent is discussed further by examining the preexponential factors, Acorr, as well as double-layer ... -
Growth and characterization of multi-walled carbon nanotubes at NASA Glenn Research Center
(American Institute of Aeronautics and Astronautics, 2003-08-17)Aligned multi-walled carbon nanotubes were prepared by the injection chemical vapor deposition (CVD) method using an iron-based organometallic compound as the catalyst source and toluene as the solvent. The concentration ... -
Laser synthesis of single-wall carbon nanotubes utilizing high temperature induction heating.
(Materials Research Society Proceedings: Nanotubes and Related Materials, 2001)An inductive heating system was used to control the temperature of the target during laser synthesis of SWNTs. The position of the target relative to the heating coil, the type of catalyst metals and the synthesis temperatures ... -
Influence of solvent reorientation dynamics upon the kinetics of some electron-exchange reactions
(Elsevier: Chemical Physics Letters, 1985-01-11)The role of solvent reorientation dynamics is explored for outer-sphere electron transfer by examining the solvent-dependent rates for electrochemical exchange of selected organometallic redox couples. The observations are ... -
Formation of single-wall carbon nanotube superbundles
(The American Chemical Society: Chemistry of Materials, 2000-03)Since their discovery in 1993, carbon single-wall nanotubes (SWNTs) have been of great interest because of their expected novel electronic, mechanical, and gas adsorption properties. Difficulties arise in measuring these ... -
Effects of alkyl amide solvents on the dispersion of single-wall carbon nanotubes
(The American Chemical Society: Journal of Physical Chemistry B, 2004-11-04)Stable dispersions of both as-produced (raw soot) and purified laser-generated single-wall carbon nanotubes (SWNTs) have been demonstrated with several alkyl amide solvents. Optical absorption analysis over a range of ...