Yttrium complexes applications

Purex process, 941 Yttrium complexes applications, 1024 Ytirium-90 serum labelling, 996... 

Lanthanide-based catalysts, despite finding a lot of application in homogeneous catalysis, can be rather problematic due to the lability of some ligand types and the versatility of their coordination chemistry in the -1-3 oxidation state this makes the controlled synthesis of single-site Ln complexes a quite ambitious goal [92]. McLain and coworkers first demonstrated the high potential of a homoleptic yttrium complex Y(OCH2CH2NMe2)3 as ROP catalyst for the preparation of PLA from rac-lactide and that it promotes a rapid and controlled polymerization... 

The first reports of LA ROP using yttrium complexes focused on homoleptic alkoxide complexes, such as cluster complexes of the form Ln5(p-0)(0R)i3 [27]. A patent, and preprint, published by DuPont described the application of a homoleptic yttrium alkoxide, Y(OCH2CH2NMe2)3, formed in situ by reaction of yttrium fm-Ao-propoxide with ALV-dimethy I am i noethanol. The complex showed a very high rate (kob = 0.5 s 1, [Y]0 = 3 mM) and reasonable polymerization control [28]. 

In addition to this wide range of uses for yttrium, new applications of yttrium complexes are under continual development. Examples include hydrate with halide and other simple ligands, with oxygen donor ligands with lanthanides, or mixed (e.g., metal diyttrium-barium and yttrium-copper), with nitrogen donor ligands, with... 

Although the conunercially available copper and yttrium precursors Cu(tmhd)2 and Y(tmhd)3(H20) readily sublime imder ambient pressures between 125 and 160°C, much higher temperatures (>250 °C) are required for the equivalent barium source, Ba(tmhd)2 . Thus, although progress has been made, currently the future development of CVD for SMO applications is hampered by the lack of suitable group 2 precursors, particularly those of Ba. Precmsor development for CVD of group 2 containing materials has focused primarily on substituted acac complexes. ... 

The yttrium concentration in seawater is 17ngkg (Zhang etal. 1994). The solution complexation of Y in seawater is similar to that of Tb, as opposed to the different reactivity with ligands on the particle surfaces (Liu and Byrne 1995). Hence, solution chemistry may help in explaining the distribution of these elements in the oceans, and this field of study might be applicable with regard to the biological effects of yttrium. 

Complex FCC oxides of the fluorite type represent oxygen-conduction solid electrolytes (SOE s). They comprise a typical class of materials for the manufacture of sensors of oxygen activity in complex gas mixtures, oxygen pumps, electrolyzers and high-temperature fuel elements. These materials are based on doped oxides of cerium and thorium, zirconium and hafnium, and bismuth oxide. Materials based on zirconium oxide, for example, yttrium stabilized zirconia (YSZ) are the most known and studied among them. This fact is explained both by their processibility and a wide spectrum of practical applications and by the possibility to conduct studies on single crystals, which have the commercial name "fianites" and are used in jewelry. 

The scandium complex 30 disclosed by Shapiro and co-workers (97), which represents the first application of the bridging amido-Cp ligand in metallocene chemistry, is imusual in its moderate ability to polymerize larger olefins such as 1-pentene. A yttrium analogue initiates polymerization of -butyl acrylate and acrylonitrile at room temperature and below (98). In the bis-Cp systems, a bridging group seems to improve reactivity toward a-olefins (99). The yttrocene dimer 31 produces highly isotactic polypropylene (Pmmmm = 97%) (100). 

Zirconium. The long half life (78.4 h) of Zr, a positron emitter, is of particular interest to immuno-PET since it can enable the longer reaction times required for radioimmunodiagnostic applications and has been explored for its potential to act as a theranostic pair with and Lu. In 2005 van Dongen et al. chelated Zr to cetuximab via succinylated desferrioxamine B (A-sucDf) with p-benzyl isothiocyanate-l,4,7,10-tetra-azacyclododecane-l,4,7,10-tetraacetic acid (p-SCN-Bz-DOTA) and p-iso-thiocyanatobenzyl diethylenetriaminepentaacetic acid (p-SCN-Bz-DTPA) for comparisons with Lu and (was used in the place of Y). The data showed that the zirconium complexes could accurately predict the lutetium and yttrium biodistribution. Subsequently, van Dongen et al. 

It was discovered that a 1 1 complex of (R,R)-BMPD [l,3-bis(2-methylferrocenyl) propane-1,3-dione] and yttrium isopropoxide, prepared in situ, was a remarkable catalyst for asymmetric silylcyanation (Scheme 12.83) [181, 182]. In the presence of 0.2 mol% of the catalyst, the reaction of benzaldehyde with TMSCN proceeded smoothly to give the desired adduct in 95% yield with 87% ee. The turnover number of this catalyst was 500. The remarkably high catalytic activity of the BMPD-yttrium isopropoxide complex showed a possibility of a practical application of this chiral Lewis acid catalyst. 

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