Thermochemical measurement of the ligand field splitting energies for hexaammine complexes of Mn(II), Fe(II), and Zn(II)

1977 ◽  
Vol 55 (20) ◽  
pp. 3530-3535
Author(s):  
M. Badri ◽  
J. W. S. Jamieson

Various lower ammines and high-energy modifications of lower ammines of the sulphates of Mn(II), Fe(II), and Zn(II) have been prepared and their heats of solution have been measured. For each of these ammine systems, the maximum difference in heat of solution, expressed in kcal/mol of heptaammine, has been found to be of the right order of magnitude to be regarded as the ligand field splitting energy for the hexaammine complex of the metal ion.

1970 ◽  
Vol 48 (14) ◽  
pp. 2177-2181 ◽  
Author(s):  
Badri Muhammad ◽  
J. W. S. Jamieson

Various normal lower ammines and high-energy modifications of the lower ammines of cobalt(II) sulfate and nickel(II) sulfate have been prepared and the heats of solution in dilute ammonia have been measured for both types. For each of these ammine systems the maximum difference in heat of solution, expressed as kcal/mole of each heptaammine, between the high-energy and the normal salts has been found to be in close agreement with the ligand field splitting energy of the hexaamminemetal(II) ion.


1979 ◽  
Vol 57 (15) ◽  
pp. 1926-1931 ◽  
Author(s):  
Muhammad Badri ◽  
James W. S. Jamieson

The vacuum dehydration of copper(II) sulphate pentahydrate has been shown to pass through the transitory trihydrate state before proceeding to the monohydrate composition. Based on this, the heat of solution data for the high-energy modification hydrates have been reinterpreted and the low-energy crystalline hydrates of various compositions have been prepared and their heats of solution measured. From the heat of solution data the maximum energy difference expressed in kcal/mol heptahydrate appears to be of the right order of magnitude to be regarded as the ligand field splitting energy for the hexaaquocopper(II) ion. Similar measurement for the ammine complexes of copper(II) sulphate has also been done and the maximum energy difference was found to agree well with the value of LFSE obtained by spectroscopic method.


1965 ◽  
Vol 43 (12) ◽  
pp. 3129-3132 ◽  
Author(s):  
J. W. S. Jamieson ◽  
R. A. Lamontagne ◽  
Barbara A. Pattern ◽  
G. R. Brown

Much higher heats of solution than have previously been observed for hydrates of zinc sulfate have been measured for various new vacuum dehydration products. It is suggested that the maximum heat of transition to normal crystalline form of 82.8 cal/g, 23.8 kcal per mole of heptahydrate, or 8.3 × 103 cm−1 is a satisfactory measure of the ligand field splitting energy for the hexaaquozinc(II) ion.


1962 ◽  
Vol 17 (8) ◽  
pp. 640-649
Author(s):  
Franz Lanzl

Using a YUKAWA interaction between the nucleons the volume energy per particle and the specific surface energy are calculated. These expressions assume a very simple form for a zero range interaction. The space parts of the applied orthogonal single particle wave functions are products of plane waves and a momentum independent function which brings about the decrease in density within the surface layer. First the volume energy per particle as a function of the density in the interior of nuclear matter is minimized. The interaction parameters are so selected that the values of the volume energy per particle and the density at the minimum agree with the experimental data. Then the surface energy as a function of the surface thickness is minimized. The values of the surface energy and the surface thickness in the minimum are compared with the empirical data. They are found to be of the right order of magnitude


1974 ◽  
Vol 29 (7) ◽  
pp. 981-990
Author(s):  
K. Dammeier

A pole regularized nonlinear spinor theory may be a suitable test object to compare scattering calculations of Stumpf's functional quantum theory with LSZ-results. To apply the LSZ-technique in this theory, a dressing of the occurring massless Green's function is necessary. It is shown which special approximations allow for this dressing. The renormalized nucleon-nucleon coupling constant yields the right order of magnitude for the elastic nucleon cross section.


2001 ◽  
Vol 18 (4) ◽  
pp. 329-335 ◽  
Author(s):  
D. J. Galloway ◽  
Y. Uchida ◽  
N. O. Weiss

AbstractSolar flares are thought to be caused by reconnection of magnetic fields and their associated electric currents in the solar corona. The currents have to be there to provide available energy over and above the current-free minimum energy state, but what generates them has been little discussed. This paper investigates the idea that twisting motions in the turbulent convection zone below may provide a natural source for the currents and explain some of their properties. The twists generate upward-propagating Alfvén waves with a Poynting flux of the right order of magnitude to power a flare. Depending on the depth it takes place, the twisting event that initiates a particular flare may occur hours, days or even months before the flare itself.


1968 ◽  
Vol 46 (24) ◽  
pp. 2745-2748 ◽  
Author(s):  
Abhai Mansingh ◽  
David B. McLay

Dielectric data have been measured for the dilute solutions in benzene at 20.0 °C of the ortho- and meta-isomers of dichlorobenzene, dibromobenzene, and diiodobenzene. The "static" dielectric constants have been measured at 100 kHz, the dielectric constants and losses have been measured at both 9.06 and 21.00 GHz, and the refractive indices have been measured at optical wavelengths. Cole–Cole plots can be fitted to the data to yield mean relaxation times τ0 and distribution parameters α. The values of the relaxation times in the ortho-isomers are 11.8, 14.9, and 20.6 ps for dichlorobenzene, dibromobenzene, and diiodobenzene respectively. The corresponding values for the meta-isomers are 8.6, 10.7, and 13.5 ps respectively, values which increase in the same direction with halogen substituent but which are significantly smaller than the relaxation times for the other isomers. All of these times are of the right order of magnitude for molecular reorientation and there is no evidence for dipole–dipole interactions. Although the nonzero values of the distribution parameters will allow mathematical descriptions in terms of two relaxation times τ1 and τ2, the values derived from two such descriptions yield two unrealistic relaxation times for each molecule. It is concluded that the analysis based on the Cole–Cole plot gives the most meaningful results.


1943 ◽  
Vol 27 (1) ◽  
pp. 37-60 ◽  
Author(s):  
David E. Goldman

Impedance and potential measurements have been made on a number of artificial membranes. Impedance changes were determined as functions of current and of the composition of the environmental solutions. It was shown that rectification is present in asymmetrical systems and that it increases with the membrane potential. The behavior in pairs of solutions of the same salt at different concentrations has formed the basis for the studies although a few experiments with different salts at the same concentrations gave results consistent with the conclusions drawn. A theoretical picture has been presented based on the use of the general kinetic equations for ion motion under the influence of diffusion and electrical forces and on a consideration of possible membrane structures. The equations have been solved for two very simple cases; one based on the assumption of microscopic electroneutrality, and the other on the assumption of a constant electric field. The latter was found to give better results than the former in interpreting the data on potentials and rectification, showing agreement, however, of the right order of magnitude only. Although the indications are that a careful treatment of boundary conditions may result in better agreement with experiment, no attempt has been made to carry this through since the data now available are not sufficiently complete or reproducible. Applications of the second theoretical case to the squid giant axon have been made showing qualitative agreement with the rectification properties and very good agreement with the membrane potential data.


1947 ◽  
Vol 28 (8) ◽  
pp. 371-380
Author(s):  
Luna B. Leopold ◽  
Charles G. P. Beer

A diurnal variation of temperature at constant levels in the lower atmosphere was observed at all stations in the Los Angeles basin area. The amplitude of the variation increases with height. This variation has been studied as a diurnal oscillation in the height of isentropic surfaces. The rise and fall of isentropic surfaces may indicate an appreciable diurnal change of vertical motion, but in the higher levels, are at least partly explained by errors in measurement of temperatures by radiosondes. In levels below 4,000 feet msl vertical motion of the right order of magnitude could be caused by the diurnal accumulation and depletion of air as a result of the sea-breeze regime.


1. The rotation of the plane of polarisation of light by a magnetic field provides perhaps one of the easiest approaches to a study of the spectroscopic behaviour of ordinary substances. The present work is an analysis of the available measures of the dispersion of this magnetic gyration. Several formulæ have been proposed for it, and these will be reviewed below, but it has proved most convenient to take one of them and use that; afterwards testing, to the rather limited extent possible, how far others would fit the facts. The test is made with the formula given by Becquerel in 1897, V = e /2 mc 2 λ dn/d λ , (1.1) where n is the refractive index, λ the wave-length and V is Verdet’s constant, the rotation of the plane of polarisation per centimetre per gauss. If this formula fits, and we shall find that it does, it should give the value of e/m . A few values were worked out by Becquerel himself on the rather meagre data available at that time, and later Siertsema obtained more accurate values for some other substances. All these gave e/m roughly of the right order of magnitude, and this fact was duly noted in the text-books and has been copied from one to another ever since, but usually without giving any numerical values at all. Since Larmor’s theorem fails to hold for molecules we should hardly expect to find the ordinary value, but nevertheless it seemed useful to analyse all the experimental measures available, so as to discover if any regularity would emerge. In the physical journals there are several results of this type for particular substances, but they are very much scattered, and it should prove convenient to collect together an analysis of all the substances for which the gyration has been measured. We are not attempting any deep theory of the matter, but merely a convenient summary which may prove useful when the time comes for a proper theory of the spectroscopic behaviour of ordinary substances of the type that has been so successful for monatomic gases and vapours. It is outside the scope of the present work to discuss the behaviour of the gyration of light of frequency very close to opaque bands ; this has been the subject of many experiments, but they are not by any means concordant, and take us deeper into the unknown theory than it is possible at present to go. To avoid this trouble we have limited ourselves to transparent substances, that is, to regions of the spectrum far from the bands which cause the optical effects. The data have been extracted from Landolt and Bornstein’s tables (edition 1921), in some cases supplemented from the original sources, and it has not, of course, been possible to assess the merit of each of the individual measures recorded. In a few cases there are measures of the gyration but not of the refraction; and we are greatly indebted to Dr. I. C. Somerville of the Chemical Department of the University of Edinburgh for measuring some of these refractive indices for us.


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