Lutetium spectra

Lanthanide bromides and iodides have found important applications in a completely different field. They are added as additives in high-pressure discharge lamps in the lighting industry to improve the arc stability and the colour quality. The latter is due to the contribution of the multiline spectrum of the doped rare earths which are added to the salt mixture. Lanthanide trihalides of dysprosium, holmium, thullium, gadolinium and lutetium are used frequently for this purpose (Hilpert and Niemann, 1997). 

Gadolinium texaphyrin (Gd-tex Figure 4.8) is reported to be an effective radiation sensitizer for tumour cells, whilst the corresponding lutetium compound, which absorbs light in the far-red end of the visible spectrum, is in Phase II trials for photodynamic therapy for brain tumours and breast cancer. 

A bis(Pentamethylcyclopentadienyl) lutetium allyl and (C5Mc5)2LuCH2-CMe=CH2 are found to be among the final products of the decomposition of (C5Me5)2LuCH2CHMe2 as shown by Watson and Roe (1982). The NMR spectrum of the allyl complex shows 5CH2 at 68 and 5CH at 163 ppm, proving a fluxional a-allyl structure. 

A highly reactive pentamethylcyclopentadienyl lutetium derivative was prepared by the reaction of bis(pentamethylcyclopentadienyl) methyl lutetium with hydrogen at 20°C in hexane (Watson, 1982 Watson and Roe, 1982). The H NMR spectrum at — 95°C (SLuH = 9.27 ppm) confirms an asymmetric structure of a dimer containing a bridging and a terminal hydrogen, which shows a rapid monomer-dimer equilibrium with AG° at 25°C for the dissociation to be less than 2 kcal/mol. 

Yb atoms, bidentate bridges are proposed (Marks and Grynkevich, 1976). The lutetium complex shows a 1 1 1 1 quartet in the H NMR spectrum at 6 = 1.07 ppm for BH4 with 7(BH) = 84 Hz (Schumann et al., 1982). The compound loses the coordinated THF reversibly upon heating in vacuo or toluene. 

Lutetium turned out to be the last natural REE and it ends the rare-earth series. Urbain was, however, of a different opinion. In 1911 he announced the discovery of a new element, celtium, placing it after lutetium in the periodic table. Later it became clear that the finding of celtium was in fact an experimental error. Urbain had interpreted its spectrum incorrectly the new lines in it were actually due to already known elements. 

Having split ytterbium and separated lutetium, the last of the REEs existing in nature, G. Urbain continued the difficult work of separating heavy rare earths. Finally, he succeeded in collecting the fraction whose optical spectrum contained new lines. This event took place in 1911 but at the time did not attract the attention of the scientific community. Perhaps Urbain himself, having suggested the name for it, was not quite sure that he had really discovered a new ele-... 

Band in the absorption spectrum of phthalocyanine lutetium form a thin layer is characterized by X, = 662 nm. This indicates that the sandwich complex is in neutral form. After treatment of the film an alcoholic solution happens recovery process. What does the reduction of the band intensity X = 662 nm, an increase in absorption X. = 618 nm and the appearance of the shoulder X = 708 nm. That the shape and position of the spectrum corresponds to phtlialocyanine blue forms. 

Vivas, M., Fernandes, R. Mendonca, R. (2012). Study of singlet excited state absorption spectrum of lutetium bisphthalocyanine using the femtosecond Z-scan technique Chemical Physics Letters 531, 173-176. 

Due to electron transitions within the 4f level, all of the lanthanide (Ln " ) ions, with the exception of lanthanum (III) and lutetium (III) which have closed-shell configurations, absorb radiation at ultraviolet or visible wavelengths of the electromagnetic spectrum. Absorptivities are not high, however, and because of shielding the absorption spectra do not, on the whole, show significant changes upon complexation of the Ln " ion. 

The tert-butylethynyl complex of lutetium, (t-BuC OjLu, obtained in the reaction of (o-Me2NCH2QH4>3Lu with t-BuOCH and identified by lutetium analysis and IR spectrum (2048s, 1363s, 1241s, 1203s), is described as a white insoluble solid [47]. 

The lutetium complex free of coordinative solvents is formed in the interaction of dimethylphosphinomethyllithium with CpjLuClCTHF) [242]. The NMR spectroscopy data, particularly the resolution of Cp groups signals in C NMR spectrum, in the author s opinion indicates the existence of intramolecular coordination P — Lu. Thus, the stabilization of the compound is achieved due to the formation of a three-membered metallocycle ... 

In contrast to the cited above data, it was reported [28] that in the synthesis of lutetium diphthalocyanine by Kirin s method the complex LuPc2 is formed. The product does not contain an amide proton N-H. The structure of complex is confirmed by the mass-spectrometry data besides the elemental analysis. In the spectrum of... 

Thus, the coefficients of the second-degree polynomial were determined based on 30 of the 40 available A,H (298)values, including the data obtained by processing the mass spectrum of lutetium trichloride after its sublimation from an EuCls-LuClsmixture (Hastie et al., 1968). This treatment shows that the enthalpy of reaction (18) for each of the lanthanide trichlorides (except europium trichloride) can be calculated by the following equation ... 

As already mentioned in the case of samarium and europium trihalides (Chervonnyi and Chervonnaya, 2007a,g), these compoimds have low enthalpies of sublimation and tend to decompose at high temperatures. Hastie et al. (1968) made an effort to stabilize the trivalent europium state. These authors prepared a mixture of europium and lutetium trichlorides, which melt at different temperatures (T = 894 K for EuCla and 1198 K for LuCla), and studied the composition of the vapor over this mixture by mass spectrometry. Data from the mass spectrum recorded at T = 960 K are presented in Table 49. At this temperature, the EuCla melt is... 

---