Volume 18, Issue 1, January 1989
Index of content:
18(1989); http://dx.doi.org/10.1063/1.555839View Description Hide Description
A great deal of solution chemistry can be summarized in a table of standard electrode potentials of the elements in the solvent of interest. In this work, standard electrode potentials and temperature coefficients in water at 298.15 K, based primarily on the ‘‘NBS Tables of Chemical Thermodynamic Properties,’’ are given for nearly 1700 half‐reactions at pH=0.000 and pH=13.996. The data allow the calculation of the thermodynamic changes and equilibrium constants associated with ∼1.4 million complete cell reactions over the normal temperature range of liquid water. Estimated values are clearly distinguished from experimental values, and half‐reactions involving doubtful chemical species are duly noted. General and specific methods of estimation of thermodynamic quantities are summarized.
18(1989); http://dx.doi.org/10.1063/1.555841View Description Hide Description
Data have been compiled on the cross sections for collisions of electrons and photons with oxygen molecules (O2). For electroncollisions, the processes included are: total scattering, elastic scattering, momentum transfer, excitations of rotational, vibrational, and electronic states, dissociation,ionization, and attachment. Ionization and dissociation processes are considered for photon impact. Cross‐section data selected are presented graphically. Spectroscopic and other properties of the oxygen molecule are summarized for understanding of the collision processes. The literature was surveyed through August 1987, but some more recent data are included when available to the authors.
18(1989); http://dx.doi.org/10.1063/1.555842View Description Hide Description
Thermal conductivities of refrigerant 12 (dichlorodifluoromethane), refrigerant 113 (1,1,2‐trichloro‐1,2,2‐trifluoroethane), refrigerant 114 (1,2‐dichloro‐1,1,2,2‐tetrafluoroethane), and refrigerant C318 (perfluorocyclobutane) were critically evaluated and correlated on the basis of a comprehensive literature survey. Recommended values were established for a wide range of temperatures and pressures, extending up to three times the critical density and excluding the critical region. Using the residual concept, a dilute‐gas function and an excess function of simple form were developed for each refrigerant. The average accuracy obtained is ∼6%.
Standard Chemical Thermodynamic Properties of Polycyclic Aromatic Hydrocarbons and Their Isomer Groups. II. Pyrene Series, Naphthopyrene Series, and Coronene Series18(1989); http://dx.doi.org/10.1063/1.555826View Description Hide Description
The tables in our first paper on polycyclic aromatic hydrocarbons [J. Phys. Chem. Ref. Data 1 7, 241 (1988)] have been extended by calculating thermodynamic properties for the first four isomer groups in the pyrene series, the first three isomer groups in the naphthopyrene series, and the first three isomer groups in the coronene series. Successive isomer groups in each series differ by C4H2. Since chemical thermodynamic properties are known for only a limited number of polycyclic aromatic hydrocarbons, the properties of individual species have been estimated using Benson group values of Stein and Fahr for temperatures from 298.15 to 3000 K. Values of C ○ P , S°, Δ f H°, and Δ f G° have been calculated in joules for a standard state pressure of 1 bar. The chemical thermodynamic properties of the individual species have also been calculated. The isomer group values provide a basis for extrapolating to higher carbon numbers where it is not feasible to consider individual molecular species.
Cross Sections for K‐shell X‐ray Production by Hydrogen and Helium Ions in Elements from Beryllium to Uranium18(1989); http://dx.doi.org/10.1063/1.555838View Description Hide Description
Experimental cross sections for K‐shell x‐ray production by hydrogen and helium ions (Z 1=1,2) in target atoms from beryllium to uranium (Z 2=4–92 ) are tabulated as compiled (7418 cross sections) from the literature (161 references were found) with the search for the data terminated in January 1988. These cross sections are compared with predictions of the first Born approximation and ECPSSR theory for inner‐shell ionization. The ECPSSR accounts for the energy loss (E) and Coulomb deflection (C) of the projectile ion as well as for the perturbed stationary state (PSS) and relativistic (R) nature of the target’s inner‐shell electron. While the first Born approximation generally overestimates the data by orders of magnitude, the ECPSSR theory is confirmed to be, on the average, in agreement with the experiment to within 10%–20%. For light and heavy target atoms, however, systematic and opposite deviations are found in the low projectile‐velocity regime. These deviations are associated with the influence of multiple outer‐shell ionizations on the fluorescence yields of light elements, particularly in ionization by helium ions, and with the inaccuracy of the ECPSSR theory in the reproduction of relativistic calculations for ionization of heavy elements. The remaining discrepancies at moderate projectile velocities are p r i m a f a c i e attributed to inadequacies of a screened hydrogenic description for the K‐shell electron.
18(1989); http://dx.doi.org/10.1063/1.555840View Description Hide Description
The rate constants for the quenching of the excited states of metal ions and complexes in homogeneous fluidsolution are reported in this compilation. Values of k q for dynamic, collisional processes between excited species and quenchers have been critically evaluated, and are presented with the following information, among others, from the original publications, when available: description of the solution medium, temperature at which k q was determined, experimental method, range of quencher concentration used, lifetime of the excited state in the absence of quencher, activation parameters, quenching mechanism. Data collection is complete through the end of 1986, and covers the coordination compounds of 26 metals, including the ions and complexes of the inner‐ and outer‐transition metals, and porphyrin complexes of nontransition metals. Data for 261 excited states quenched by more than 400 inorganic quenchers and 600 organic quenchers have been extracted from almost 500 publications. The introduction to the work contains a discussion of the conceptual background to quenching, including a general treatment of the kinetics, an explanation of the tables, and a list of recent review articles. Uncommon kinetics mechanisms and equations, used to obtain the reported values of k q , are discussed in detail as part of the notes to the tables. Indexes of excited states, quenchers, and authors are appended.