Paramagnetic moment, rare earth elements

The presence of the phthalocyanine radical anion in R(Pc )(tmhd)2 (R=Y,Nd, Sm-Lu) is also supported by the magnetic, ESR and Raman spectroscopic studies (Sugimoto et al. 1983b). The magnetic moment of the diamagnetic Y and Lu is 1.65 BM which is close to the tree-spin value. Their ESR spectra, both in the solid state and in benzene solution, show a signal centered at the tree-spin value at g=2.001. The shape and g-value are characteristic of those of H(Pc ) and Li(Pc ). Complexes with paramagnetic rare-earth elements are ESR-silent, probably due to the spin-spin relaxation... 

Gadolinium, like other related rare earth metals, is silvery white, has a metallic luster, and is malleable and ductile. The element is relatively stable in dry air but in moist air tarnishes with the formation of a loosely adhering oxide film. The metal reacts slowly with water and is soluble in diluted acid. Gadolinium exhibits a trivalent oxidation state and because of the half-filled 4f level the Gd " " ion is especially stable and unique for its high paramagnetic moment. It has the highest thermal neutron capture cross-section of any known element. 

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