Samarium compounds

In the presence of samarium(II) iodide, A-(2-iodobenzyl)dialkylamines 347 react with electrophiles at an a-carbon atom to yield deiodinated products by way of intermediate samarium compounds 348. Thus TV-(2-iodobenzyl)diethylamine and pentan-3-one afford the hydroxy amine 349 and 7V-(2-iodobenzyl)pyrrolidine and propyl isocyanate give the amide 350390. 

Some data on samarium compounds are available. For the 650-m/n emission peak Bhaumik et al (171) find for samarium benzoylacetonate microcrystals 15 /nsec at both 300° and 90°K. The compound samarium dibenzoylmethide has a lifetime of 45 /nsec at both 300° and 90°K, while Dieke and Hall (88) report a value of around 10 /nsec for the hydrated chloride at the same temperatures. 

Samarium Compounds t-Butoxydiiodosamarium, 272 Diiodomethane-Samarium, 113 Diiodomethane-Samarium iodide, 113 Samarium, 113... 

Another completely different approach consists in choosing a dye, that already possesses aminocarboxylate functions (Meshkova et al., 1992a), such as triphenylmethane dyes. The latter can be used for selective luminescent determination of Nd111 and Ybm in samarium oxide, for instance. As previously described in the section devoted to /3-diketonates (section 3.2.1), the triplet excited states of /i-dikctonatcs lie at energies >20 000-25 000 cm-1, above most of the accepting levels of Lnm ions. As a consequence, determination of Ndm and Yb111 in europium or samarium oxides is difficult using /3-dike to nates since these two ions exhibit luminescence in the NIR, especially Smm with emission lines at 908, 930, 950, and 1038 nm close to the analytical lines of Ndm and Ybm. Therefore, the detection limit of Ndm and Ybm in samarium compounds by luminescence of their ternary complexes with tta and phen is only 0.1-1 wt%. 

The catalysts are Tim hydrides which are generated in situ by reduction of enantio-merically pure L TiCl2 with butyllithium and PhSiH3 they are also highly effective in the asymmetric hydrogenation of imines and enamines.20 The lutetium ansa-metallocene complex (22-XVII) catalyzes the deuteration of 1-pentene (63% e.e.)21 Related samarium compounds hydrogenate imines.22... 

Recently, Wakatsuki and co-workers have shown that samarium compounds produce SPS with lower syndiotacticity than titanium compounds [9]. 

Another important metal for Barbier-type reaction is samarium. Allyl bromide reacts with a ketone and Sm to give the homoallylic alcohol. Samarium compounds, such as Sml2, can also be used with allylic halides. 

Samarium metal poses a threat to workers who may come into contact with it and its fumes. When inhaled, those fumes may damage the lungs and, over long periods of time, affect the liver. Very little information is available on the health hazards of samarium compounds, although they are suspected of being irritants to the skin, eyes, and respiratory system. 

Kagan, H. B. Divalent samarium compounds perspectives for organic chemistry. New J. Chem. 1990, 14, 453-460. 

Properties Pink crystals. Soluble in water. Technical grade contains 75% neodymium salt, principal impurities praseodymium and samarium compounds. 

Double chromates of lanthanum, promethium and neodymium of the type RbLn-(Cr04)2 have been found to be anhydrous. The samarium compound crystallized with 0.5 molecules of water whilst those from europium to lutetium had the composition RbLn(Cr04)2,H20. Y-Ray and i.r. studies showed the existence of three structural types as the rare earth element series was transversed. 

Samarium Compounds f Buiuxydiiodosamarium. 272 OjiDdomethaoe-Samanum, 113 IMiodomclhanc-Samatium iodide. 113 Samanum. 113... 

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