@article {860,
	title = {Muonium formation as a probe of radiation chemistry in sub- and supercritical carbon dioxide},
	journal = {Journal of Physical Chemistry A},
	volume = {108},
	number = {52},
	year = {2004},
	note = {ISI Document Delivery No.: 882FPTimes Cited: 5Cited Reference Count: 97},
	month = {Dec},
	pages = {11613-11625},
	type = {Article},
	abstract = {Muonium (Mu = mu(+)e(-)), which can be considered a light isotope of the H atom, has been observed for the first time in supercritical CO2 (ScCo2). It is Unreactive on a time scale of a few microseconds and over a wide density range from well below to well above the CO2 critical density rho(c) = 0.47 g/cm(3). The fraction of muon polarization in muonium, P-Mu, does not vary significantly at low densities but changes quickly at the highest densities, approaching zero. This density dependence is reflected in a concomitant increase observed in the lost fraction of polarization, P-L, demonstrating that the dynamics of Mu formation and depolarization in ScCO2 is a direct probe of radiolysis effects in the terminal muon radiation track. In marked contrast to previous studies in hydrogen-containing solvents, C2H6 and H2O, over comparable density ranges, the diamagnetic fraction, P-D, was found to be almost independent of density in CO2, attributed to the formation of the stable solvated MuCO(2)(+) molecular ion in this hydrogen-free solvent. The differing density dependences of both the Mu and the diamagnetic fraction in Co-2, in comparison with the rather similar trends seen for both in C2H6 and H2O, supports previous claims of a significant role played by proton (muon) transfer reactions in the competing processes involved in Mu formation in hydrogen-containing solvents. In addition to this being the first report of radiolysis effects accompanying energetic positive muons stopping in ScCO2, it is the only report of end of track effects in this solvent, which has many applications in nuclear waste management and green chemistry. With a mass intermediate between that of the electron, which has provided most radiation-chemistry studies in ScCO2 to date, and the proton (or alpha-particle), implanted muons provide a unique data set, characteristic of higher LET radiation, that may be relevant to radiolysis effects induced in ScCO2 by alpha decay from heavy nuclei, for which there are no comparable studies.},
	keywords = {AQUEOUS-SOLUTIONS, CROSS-SECTIONS, EXCESS ELECTRON-TRANSPORT, GAS-PHASE, LIQUID WATER, MAGNETIC-RESONANCE, ORGANIC FREE-RADICALS, PRESSURE-DEPENDENCE, relaxation, SOLVENT ANIONS, SPIN},
	isbn = {1089-5639},
	url = {<Go to ISI>://000225924800018},
	author = {Ghandi, K. and Bridges, M. D. and Arseneau, D. J. and Fleming, Donald G.}
}
@article {4418,
	title = {Structural, spectroscopic, thermodynamic and kinetic properties of copper(II) complexes with tripodal tetraamines},
	journal = {Inorganic Chemistry},
	volume = {37},
	number = {16},
	year = {1998},
	note = {ISI Document Delivery No.: 110GETimes Cited: 87Cited Reference Count: 38},
	month = {Aug},
	pages = {4022-4029},
	type = {Article},
	abstract = {Spectroscopic, thermodynamic, and kinetic measurements have been made on aqueous solutions of copper(II) complexes of hexamethylated tren and trimethylated tren (one methylation per primary amine group of tren) with the objective of correlating: the influence of geometry (trigonal bipyramidal, evident from UV/vis spectroscopy) and N-alkyl substitution in the ligand on these inherent properties. At 25.0 degrees C the protonation constants of Me(3)tren are not significantly different from those of tren and Me(6)tren, and the stability constant for the Cu(II) complex is of the same order of magnitude as that for the [Cu(tren)(H2O)](2+) complex ion; The pK(a) for deprotonation of the coordinated water molecule of [Cu(Me(3)tren)(H2O)](2+) is intermediate between the values for the complexes containing the unsubstituted and the fully substituted tren ligand. Substitution (pyridine for water) kinetics measurements employing stopped-flow and temperature-jump methods revealed different patterns of reactivity: pyridine replaces water in [Cu(Me(3)tren)(H2O)](2+) with a second-order rate constant of (4.4 +/- 0.8) x 10(2) M-1 s(-1) at 25.0 degrees C, whereas the corresponding process for [Cu(Me(6)tren)(H2O)](2+) is relatively complex and is discussed in more detail. Substitution in the former complex ion is characterized in the forward and reverse directions, by Delta H-double dagger = 60 +/- 8 and 51.9 +/- 0.9 kJ mol(-1), Delta S-double dagger = 5 +/- 27 and -23 +/- 3 J mol(-1) K-1, and Delta V-double dagger = -8.7 +/- 4.6 and -6.2 +/- 1.1 cm(3) mol(-1), respectively, It is concluded that this reaction follows an I-a mechanism, similar to that reported for the comparable reaction of [Cu(tren)(H2O)](2+). An X-ray structural determination on a crystal of [Cu-2(Me(3)tren)(2)(CN)] (ClO4)(3) . 2CH(3)CN demonstrated trigonal bipyramidal geometry about each copper(II) center. As has been found in comparable complexes of tren and Me(6)tren, the axial nitrogen to copper bond is shorter than the equatorial nitrogen-copper bonds, and the angle made by N(axial)-Cu-N(equatorial) is less than 90 degrees (84.6-85.4 degrees), signifying that each copper ion lies below the plane of the equatorial nitrogen atoms.},
	keywords = {AQUEOUS-SOLUTION, CRYSTAL-STRUCTURE, ELECTRONIC-PROPERTIES, IMIDAZOLE, ION, MECHANISM, PHENANTHROLINE, PRESSURE-DEPENDENCE, RESONANCE, SUBSTITUTION KINETICS},
	isbn = {0020-1669},
	url = {<Go to ISI>://000075371200019},
	author = {Thaler, F. and Hubbard, C. D. and Heinemann, F. W. and vanEldik, R. and Schindler, S. and Fabian, I. and Dittler-Klingemann, A. M. and Hahn, F. E. and Orvig, Chris}
}
@article {3837,
	title = {Theory of muon spin relaxation of gaseous C(2)H(4)Mu},
	journal = {Physical Review A},
	volume = {54},
	number = {6},
	year = {1996},
	note = {ISI Document Delivery No.: VX714Times Cited: 5Cited Reference Count: 32},
	month = {Dec},
	pages = {4815-4829},
	type = {Article},
	abstract = {A theoretical study of the muon spin relaxation of the gaseous muonated ethyl radical C(2)H(4)Mu is expanded in this paper to include both longitudinal and transverse signals. This study is based upon an operator expansion of the spin-density operator for the radical with its time dependence described by the linearized quantum Boltzmann equation. Relaxation is due to collisions which reorient the radical{\textquoteright}s rotational angular momentum while effects on the muon{\textquoteright}s spin are due to couplings between the muon{\textquoteright}s spin, the radical{\textquoteright}s free-electron spin, and the radical{\textquoteright}s rotational angular momentum. The coefficients of the radical{\textquoteright}s spin Hamiltonian and the collisional lifetimes (cross sections) are used as fitting parameters to describe the transverse signals. A fit to the transverse data by itself and a global fit to both the transverse and longitudinal data are obtained with good accuracy.},
	keywords = {CHARGE-EXCHANGE, CONSTANTS, FREE-RADICALS, GAS-PHASE, IRREDUCIBLE CARTESIAN TENSORS, KINETIC-EQUATIONS, PRESSURE-DEPENDENCE, RESONANCE},
	isbn = {1050-2947},
	url = {<Go to ISI>://A1996VX71400033},
	author = {Turner, R. E. and Snider, R. F.}
}
@article {3473,
	title = {MU+NO - KINETIC ISOTOPE EFFECTS IN UNIMOLECULAR DISSOCIATION},
	journal = {Journal of Physical Chemistry},
	volume = {99},
	number = {47},
	year = {1995},
	note = {ISI Document Delivery No.: TF811Times Cited: 10Cited Reference Count: 80},
	month = {Nov},
	pages = {17160-17168},
	type = {Article},
	abstract = {The thermal addition reaction Mu + NO + M reversible arrow MuNO* + M has been studied by a longitudinal magnetic field muon spin relaxation (mu SR) technique, at room temperature, in the presence of up to 60 atm of N-2 as inert moderator. The pressure dependence of the effective rate constant for Mu addition (k(eff)) demonstrates that the system remains well in the low-pressure regime in this pressure range. The termolecular rate constant, k(0)(Mu) = (8.76 +/- 0.46) x 10(-33) cm(6) molecule(-2) s(-1), is about 5 times smaller than that reported for the corresponding H-atom reaction (Tsang, W.; Herron, J. T. J. Phys. Chem. Ref. Data 1991, 20, 609), the largest isotope effect of its kind yet reported for reactions of this nature and most likely due to the increased rate of MuNO* dissociation resulting from the much lighter mass of the Mu atom (m(Mu)/m(H) similar to 1/9). This result should provide an important test of theoretical calculations for dissociating molecules involving few degrees of freedom. Quantum tunneling, normally facile for the much lighter Mu atom, is unlikely to play a major role in establishing the isotope effect seen in k(0). In the present instance, the mu SR technique relies on measuring the relaxation rate for the chemical process of addition (lambda(c)) in competition with that for spin exchange (lambda(se)), with the NO unpaired electron. The pressure-independent average value for the spin exchange rate constant found, k(se) = (3.00 +/- 0.12) x 10(-10) cm(3) molecule(-1) s(-1), is in good agreement with previous values obtained by transverse field mu SR (Fleming, D. G., et al. J. Chem. Phys. 1980, 73, 2751).},
	keywords = {CHANNEL MODEL-CALCULATIONS, CHARACTERIZATION, ELECTRON-SPIN EXCHANGE, H+CH3->CH4 RECOMBINATION, INTERPOLATED, MICROCANONICAL VARIATIONAL THEORY, PARTITION-FUNCTION, POTENTIAL-ENERGY, PRESSURE-DEPENDENCE, RADICAL RECOMBINATION, RATE CONSTANTS, SURFACES, THEORETICAL},
	isbn = {0022-3654},
	url = {<Go to ISI>://A1995TF81100019},
	author = {Pan, J. J. and Senba, M. and Arseneau, D. J. and Gonzalez, A. C. and Kempton, J. R. and Fleming, Donald G.}
}
@article {3183,
	title = {THEORY OF MUON SPIN RELAXATION OF SIMPLE GASEOUS FREE-RADICALS},
	journal = {Physical Review A},
	volume = {50},
	number = {6},
	year = {1994},
	note = {ISI Document Delivery No.: PX179Times Cited: 9Cited Reference Count: 30Part A},
	month = {Dec},
	pages = {4743-4754},
	type = {Article},
	keywords = {CHARGE-EXCHANGE, CONSTANTS, GAS-PHASE, IRREDUCIBLE CARTESIAN TENSORS, KINETIC-EQUATIONS, PRESSURE-DEPENDENCE},
	isbn = {1050-2947},
	url = {<Go to ISI>://A1994PX17900035},
	author = {Turner, R. E. and Snider, R. F.}
}
@article {7172,
	title = {KINETIC ISOTOPE EFFECTS IN GAS-PHASE MUONIUM REACTIONS},
	journal = {Acs Symposium Series},
	volume = {502},
	year = {1992},
	note = {ISI Document Delivery No.: JY550Times Cited: 16Cited Reference Count: 101},
	pages = {111-137},
	type = {Review},
	abstract = {The study of the reaction dynamics of muonium (Mu), an ultralight isotope of hydrogen ((m)Mu/(m)H almost-equal-to 1/9), provides a sensitive measure of mass effects in chemical reactions. The remarkable mass difference between Mu and the other hydrogen isotopes produces large kinetic isotope effects, providing a rigorous test of calculated potential energy surfaces (PES) and reaction rate theories. The low Mu mass also necessitates careful consideration of quantum effects, i.e. tunneling in the reaction coordinate. A review of recent results in gas phase Mu chemistry is presented, including comparison with relevant H chemistry and calculated PESs, where available. The magnitude and direction of the kinetic isotope effect is shown to be a sensitive function of the PES, particularly the height and position of the saddle point.},
	keywords = {+ HBR(DBR) ABSTRACTION, ACTION, ADDITION-REACTIONS, CALCULATIONS, CHARGE-EXCHANGE, COLLISIONS, LOW-TEMPERATURES, POTENTIAL-ENERGY SURFACES, PRESSURE-DEPENDENCE, RESONANCE, THERMAL RATE CONSTANTS, TRANSITION-STATE THEORY, TUNNELING PATHS},
	isbn = {0097-6156},
	url = {<Go to ISI>://A1992JY55000008},
	author = {Baer, S. and Fleming, Donald G. and Arseneau, D. and Senba, M. and Gonzalez, A.}
}
