Magnetic moments of first row transition

A larger number of examples of 5f- 3d systems are known, and have been recently reviewed [43]. We reiterate here only the potentially enormously beneficial effect of sizable 5f-3d exchange couplings exploiting the large magnetic moments of first row transition metal ions and the anisotropy of actinides. Examples are the previously discussed U-Mn wheel and chain [36, 38]. 

Table 2 Typical experimental magnetic moments of first-row transition metal-ion complexes compared with theoretical predictions...

A number of calculated and experimental magnetic moments for first-row transition metal complexes are given in Table 11.26, showing that the spin-only formula gives results that are in reasonably good agreement. 

Table 2.23 Magnetic moment, reflectance spectral data, and proposed stereochemistry of first row transition metal methoxides and ethoxides...

From the Slater-Pauling curve for the saturation magnetic moment of the first-row transition metal alloys (Figure 1), it was found empirically that the number of metallic orbitals per atom has the value 0.72, corresponding to 28% M+, 44% M°, and 28% M-. Based on the statistical treatment discussed in the preceding section, it is now possible to deduce this value on purely theoretical grounds [36]. 

The magnetic moment is due to unpaired electron spins. Magnetic susceptibilities are positive as shown in Table 33.5, because the magnetic moments line up with H and this leads to an increase in B. However, adjacent magnetic dipoles essentially behave independently there is no interaction between them. It is this lack of an interaction that separates paramagnetic materials from ferromagnets. Most first row transition metals, e.g., Ti and Cr, are... 

The number of unpaired electrons, In turn, can be predicted on the basis of crystal field theory (see Chapter 16) and whether or not the molecule has a high-spin (HS) or low-spin (LS) electronic configuration. The experimental and calculated values of the effective magnetic moments for the first-row transition metals are listed in Table 15.5. 

TABLE 15.5 Calculated and experimental effective magnetic moments for the octahedral first-row transition metals in units of Bohr magnetons. 

If the effective magnetic moment of a first-row transition metal is 6.92 Bohr magnetons, what is its electron configuration ... 

Tab. 1 gives a survey of the ranges for observed effective magnetic moments of the first row transition metal ions. 

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