| AUTHOR |
TITLE |
Xie, B.,
Elder, T.,
Wilson, L. J.,
Stanbury, D. M. |
Internal Reorganization Energies for Copper Redox Couples: The Slow Electron-Transfer Reactions of the [CuII/I(bib)2]2+/+ Couple
Inorganic Chemistry; 1999; 38(1); 12-19. |
Experimental Section
Stock solutions of Cu(II) were prepared by weight. The decay of the absorbance of Co(II) was monitored at 472 nm for about 10 half-lives. The data were transferred to an OLIS 4300S system for data analysis; values of the pseudo-first-order rate constants, kobs, were obtained by fitting the absorbance data with an exponential decay function. Values of kobs were reproducible ±5% or better. |
Sun, J.,
Stanbury, D. M. |
Kinetics and Mechanism of the One-Electron Reduction of Iodine by [RuII(NH3)5isn]2+ in Aqueous Solution
Inorganic Chemistry; 1998; 37(6); 1257-1263. (Article) |
Methods
An OLIS 4300 S system was used for data acquisition and analysis. Reactions were monitored at 480 nm, and the rate constants were obtained by fitting the data with OLIS-supplied first-order functions. A nonlinear-least-squares computer program was used to fit the overall rate law to the values of kobs.
An OLIS RSM-1000 rapid-scan UV-vis/USA stopped-flow instrument was used to examine the reaction spectra. This experiment was run at room temperature, the other conditions being [Ru(II)]0 = 53 µM, [I2]0 = 0.47 mM, [H+] = 0.01 M, and µ= 0.1 M (NaClO4). |
Doona, C. J.,
Stanbury, D. M. |
Equilibrium and Redox Kinetics of Copper(II)-Thiourea Complexes
Inorganic Chemistry; 1996; 35(11); 3210-3216. (Article) |
Experimental Section
All measurements of the Cu(II)-tu reaction were carried out at 25 °C using an Olis RSM-1000 optical/data-acquisition/analysis system interfaced to an Olis USA-SF stopped-flow unit with a 1.7 cm path length. A Hi-Tech SF-51 stopped-flow instrument (1.0 cm path length) operating at 410 nm and interfaced to an Olis 4300 data acquisition and analysis system was used to measure the [IrCl6]2--tu reaction at 25 °C with and without added copper(II). Absorbance spectra of the Cu(II)-tu reaction products qualitatively confirm the formation42 of (tu)22+, which parallels the disulfides produced by many copper(II) oxidations of thiols.43 The water used throughout this entire work was purified by distilling doubly-deionized water with a Barnstead/Fi-streem glass still. |
Chang, C. J.,
Connick, W. B.,
Low, D. W.,
Day, M. W.,
Gray, H. B. |
Electronic Structures of Nitridomanganese(V) Complexes
Inorganic Chemistry; 1998; 37(12); 3107-3110. (Article) |
Experimental Section
Physical Measurements. Solution absorption spectra were obtained using either a Cary 14 spectrophotometer upgraded by On-Line Instrument Systems (OLIS) to include computer control or a Hewlett-Packard 8452A diode array spectrophotometer. |
Klein Gebbink, R. J. M.,
Martens, C. F.,
Kenis, P. J. A.,
Jansen, R. J.,
Nolting, H.-F.,
Sole, V. A.,
Feiters, M. C.,
Karlin, K. D.,
Nolte, R. J. M. |
Synthesis, Structure, and Reactivity of Copper Dioxygen Complexes Derived from Molecular Receptor Ligands
Inorganic Chemistry; 1999; 38(25); 5755-5768. |
Experimental Section
Low-Temperature UV-vis Spectroscopy. The low-temperature UV-vis spectra were obtained on a Hewlett-Packard 8452A diode array spectrophotometer driven by a Compaq Deskpro 386S computer using a software system writen by On-Line Instrument Systems Inc. The spectrophotometer was equipped with a Kontes KM-611772 variable-temperature UV-vis Dewar cell with quartz windows. The low temperature inside the Dewar assembly was achieved by putting a copper tubing coil inside the methanol-filled Dewar cell. Through the coil cold methanol was circulated by an external cooling unit (Neslab CC-100II cryocool immersion cooler, in Agitainer A with circulation pump). The cuvette assembly consisted of a quartz cuvette fused to one end of a glass tube. The other end was attached to a high-vacuum-stopcock and a 14/20 ground glass joint. The temperature inside the Dewar assembly was monitored by an Omega model 651 resistance thermometer probe. |
Kopf, M.-A.,
Neuhold, Y.-M.,
Zuberbuhler, A. D.,
Karlin, K. D. |
Oxo- and Hydroxo-Bridged Heme-Copper Assemblies Formed from Acid-Base or Metal-Dioxygen Chemistry
Inorganic Chemistry; 1999; 38(13); 3093-3102. |
Experimental Section
UV-visible spectra were recorded on a Shimadzu 160 spectrophotometer or a Hewlett-Packard 8452A diode-array spectrophotometer driven by a Gateway 2000 P75 computer using software written by On-Line Instruments Systems, Inc. |
Al-Ajlouni, A. M.,
Gould, E. S. |
Electron Transfer. 139. Reductions with Trioxodinitrate, [N2O3]2-
Inorganic Chemistry; 1999; 38(7); 1592-1595. |
Experimental Section
Kinetic Studies. Rates were evaluated from measurements of absorbance changes using a Shimadzu 1601 recording spectrophotometer or a Durrum-Gibson stopped-flow spectrophotometer interfaced with an OLIS computer system. Most usually, decreases at 250 nm due to loss of trioxodinitrate were followed, but in some cases, the change in a colored coreagent was monitored. Temperatures were kept at 22.0 ± 0.5 °C. Ionic strength was maintained at 0.20 M by addition of NaClO4. Acidities were regulated by measured quantities of buffering acids and NaOH. For kinetic runs, solutions of the oxidant and the buffering acid were added to solutions of N2O32- in base, thus minimizing the loss of the reductant by acid-catalyzed self-decomposition9 prior to mixing; pH values of the redox mixtures were checked at the conclusion of each reaction. |
Chandra, S. K.,
Paul, P. C.,
Gould, E. S. |
Electron Transfer. 135. Pendant Carbonyl Groups in the Mediation of the Reactions of Indium(I) with Bound Ruthenium(III)1
Inorganic Chemistry; 1997; 36(21); 4684-4687. (Article) |
Experimental Section
Kinetic Experiments. Reactions, under argon, were examined at or near the high-wavelength maximum of the Ru(II) product, using either a Cary 14 instrument or a Durrum-Gibson stopped-flow spectrophotometer interfaced with an OLIS computer system. Ionic strength was regulated by addition of NaClO4/HClO4. Reductions with Ti(III) were carried out with the reductant in excess, whereas those with In(I) were run with Ru(III) in excess to avoid formation and precipitation of elementary ruthenium. Concentrations of reagents were generally adjusted so that no more of 10% of the reactant in excess was consumed in the reaction. Reductions by Ti(III) yielded simple exponential curves, and rate constants were obtained by nonlinear least-squares fitting to the relationship describing pseudo-first-order decay. These reactions were first order in both redox partners. |
Chandra, S. K.,
Gould, E. S. |
Electron Transfer. 134. Reduction of Bound Ruthenium(III) by Indium(I)1
Inorganic Chemistry; 1997; 36(16); 3485-3487. (Article) |
Experimental Procedures
Kinetic Experiments. Reactions, under argon, were examined at the high-wavelength maximum of the Ru(II) product, using either a Cary 14 recording spectrophotometer, a Beckman Model 5260 instrument, or a Durrum-Gibson stopped-flow spectrophotometer interfaced with an OLIS computer system. Ionic strength, which was regulated by addition of NaClO4/HClO4, was generally maintained at 0.2 M. Concentrations of reagents were customarily adjusted so that no more than 10% of the reactant in excess was consumed in the reaction. In no case was kinetic variation with acidity perceived within the range [H+] = 0.030-0.10 M. All reactions in the present series yielded simple exponential curves, and rate constants were obtained by nonlinear least-squares fitting to the relationship describing first-order decay. |
Al-Ajlouni, A. M.,
Gould, E. S. |
Electron Transfer. 132. Oxidations with Peroxynitrite1
Inorganic Chemistry; 1996; 35(26); 7892-7896. (Article) |
Experimental Section
Kinetic Studies. Rates were evaluated from measurements of absorbance decreases at 300 nm using a Beckman Model 5260 recording spectrophotometer or a Durrum-Gibson stopped-flow spectrophotometer interfaced with an OLIS computer system. Temperatures were kept at 25.0 ± 0.5 °C. |
