Magnetic susceptibility data

The polarizability, ionization potential, and magnetic susceptibility data from the last edition of the Landolt-Bornstein tables are given in Table I for the inert gases and for H2, Na, Ci2, and CH4. The coefficients of the dipole-dipole or R 6 potential term are... 

There will exist an equilibrium between the two states. If the ener between the two states, E, is of the order of kT, then the relative populations of the two states will vary with the temperature of the sample. In the Fe(III) dithiocarbamate series of complexes, [FeCRiRgdtcla], AE can be varied by suitable choice of substituents Ri and Rj. Although these are well removed from the FeSg molecular core, they can appreciably affect the electronic parameters of the central iron atom and of the surrounding crystal field of the sulfur atom by way of the conjugated system of the ligand (237). The results of the spin crossover are reflected in magnetic susceptibility data. 

In all cases, the high-temperature magnetic susceptibility data are consistent with Eu being all Eu. ... 

Magnetic susceptibility data are inferred to have been reflected by hydrothermal activity. The magnetic susceptibility data on the sedimentary rocks are shown in... 

Fig. 21. Ethylene oxidation to ethylene oxide (O) and CO2 (O) over Pd-Ag alloy films. Magnetic susceptibility data ( ) (14%) and heats of oxygen chemisorption ( ) (.131) are also included (1S6).

Rotating single-crystal measurements also permitted the extraction of the orientation of the magnetic tensor in the molecular reference frame and the experimental easy axis was found to coincide with the idealized tetragonal axis of the coordination dodecahedron of Dy. Crystal field calculations assuming idealized tetragonal symmetry permitted the reproduction of magnetic susceptibility data for gz = 19.9 and gxy 0 [121]. More elaborated calculations such as ab initio post Hartree-Fock CASSCF confirmed this simple analysis [119]. 

Magnetic susceptibility data for LiZn2Mo308 showed Curie-Weiss... 

In contrast, (BDTA)[Ni(dmit)2]2 has been fully characterized [89] (X-ray structure, magnetic susceptibility data, band structure and conductivity). It exhibits an SC behavior with a room-temperature conductivity of 0.1 S cm-1. Its magnetic behavior is dominated by AFM interactions, probably due to the coupling between the Ni(dmit)2 moieties. Although its properties are not spectacular, this complex is the first well-characterized example of a salt containing partially-oxidized Ni(dmit)2 moieties with a radical cation. 

Wilson et al. [27] showed that the introduction of steric hindrance in the 6-position of one or two of the pyridine groups was sufficient to fine-tune the ligand field and obtain crossover compounds. These systems have been investigated using a number of different techniques, both in the solid and solution phases. Thermodynamic parameters have been derived from variable temperature magnetic susceptibility data for the single methyl-substituted (23 ) (AH°=19.7 kj mol"1, A5°=39.8 J mol"1 K"1), the double methylsubstitut-... 

As indicated in the previous discussion, Mossbauer spectroscopy provides information that when coupled with results using other structural techniques assists in determining the structure of the complex under analysis. The relationships between the various techniques are summarized in Table II. The Mossbauer chemical shift provides information about the 4 electron contribution to the bond between the metal and the ligands in a complex. Similar estimates can be obtained from the results of measurements on the fine structure in the x-ray absorption edge and nuclear magnetic resonance data. The number of unpaired electrons can be evaluated from magnetic susceptibility data, electron spin resonance, and the temperature coeflScient of the Mossbauer quadrupole splitting (Pr). 

Penney and Schlapp, Van Vleck and others applied these results to interpret magnetic susceptibility data of paramagnetic transition group ions in crystals. More recently, the theory has been applied with considerable success to electron magnetic resonance data 126,140,14I) and to the optical spectra 142) of paramagnetic ions in solids. 

The EPR data are of course intimately related to magnetic susceptibility data. The Weiss constant of the 5-phase is proportional to D which will amount to only a few degrees Kelvin at most, while the Weiss constant of the /8-phase is large due to the large exchange effects in this phase. The Weiss constant obtained from a magnetic susceptibility measurement is thus due predominantly to the /8-phase. 

Determined fiom fits of variable temperature solid state magnetic susceptibility data, unless otherwise noted. 

The anhydrous form is rarely if ever used for catalysis, as is the case with anhydrous RuOj. It exists in two modifications. The black a-form is made by heating P-RuClj to 600°C in vacuo, and has the laminar a-TiClj structure also found in CrClj and FeClj with a distorted octahedral structure (Ru-Cl distance 2.40 A). The brown P-form has the P-TiClj structure with linear polymers of RuClj units, the metal atoms having distorted octahedral coordination (Ru-Ru 2.68 A, Ru-Cl 2.30(7) and 2.39(7) A). Infrared spectra and magnetic susceptibility data were recorded for both forms [712]. The toxicological properties of RuClj have been listed it may give off toxic RuO when heated, and is mildly toxic by intraperito-neal routes [238]. 

Rhenium metal exhibits a very low paramagnetism which is field-independent and almost temperature-independent. In the range 79—471 K, magnetic susceptibility data for two independent samples were shown to correspond, when Tis in Kelvin, to the following equations (5) ... 

Figure 6.27 Single-crystal magnetic susceptibility data of CsNiFj. (After Tressaud Dance, 1982.) The solid line is the theoretical curve for Jjk = 10.2 K.

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