Thulium electronic structure

The same arguments apply to the study of ionization thresholds. While some success has been possible for the elements with simpler electronic structure (ytterbium, europium, and thulium),(34>35) for the remainder of the lanthanides it is nearly an impossible task to unravel the spectra originating from the many populated metastable levels to accurately determine the ionization potential with confidence.(36)... 

Treatment of thulium diiodide with substituted phospholide and arsolide salts afforded stable bis(phospholyl)- and bis(arsolyl)thulium(ll) complexes (Scheme 201) as green solids, that were characterized by multinuclear NMR and X-ray crystal structures. The latter clearly revealed the beneficial effects of the steric and electronic properties of crowded phospholyl and arsolyl ligands for the stabilization of divalent thulium.727 Several other homoleptic samarium(ll) and thulium(n) phospholyl sandwich complexes containing the 2,5-di-/-butyl-3,4-dimethylphospholide (=dtp) or 2,5-bis(trimethylsilyl)-3,4-dimethylphospholide (=dsp) ligand have been synthesized and structurally characterized. X-ray studies revealed that [Sm(dtp)2]2 and [Sm(dsp)2]2 are both dimeric in the solid state due to... 

Thulium (Tm) is a unique heavy lanthanide element. It is the last heavy lanthanide with an incomplete 4f shell. In the lanthanide series, thuhum is followed by ytterbium, which has a divalent electronic character and does not show the typical structural changes observed in other trivalent lanthanide elements. And the last element in the lanthanide series lutetium also has a completely filled 4f shell, and therefore is not expected to exhibit low symmetry structures at ultra high pressures. 

The temperature dependence of the quadrupole splitting of Tm in TmES yielded an estimate of the values of the CEF parameters for the Tm ion in the ethylsulfate structure. Since optical absorption spectroscopy had previously furnished estimates of the four parameters needed to characterize the CEF in this structure [Wong and Richman (1961)], their determination in this case provided a valuable cross-check on the validity of the method which has been outlined in section 2.1.3. The experiments also revealed a substantial shielding of the 4f electrons from the crystal field, as has been described for the case of thulium metal in section 2.1.3. 

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