Samarium , crystal structure

Samarium, tris(triphenylphosphine oxide)bis-(diethyldithiophosphato)-structure, 1,78 Samarium complexes dipositive oxidation state hydrated ions, 3, 1109 Samarium(III) complexes salicylic acid crystal structure, 2, 481 Sampsonite, 3, 265... 

These new silyl complexes are monomeric in benzene solution, but are dimeric in the solid state. The crystal structure of the samarium analogue (Figure 1) shows that dimers form via intermolecular Sm-CH3-Si interactions. The Sm-Si distance, 3.052 (8) A, is to our knowledge the longest metal-silicon distance known. As with other complexes that display Ln-CH3-Si interactions in the solid state, evidence for these interactions in solution is not observed in NMR spectra. The [H NMR chemical shifts for the neodymium... 

The crystal structure of the 1 2 adduct 145 obtained by the reaction of [Cp SmH]2 with MMA was determined by X-ray analysis. One of the two monomer units is in the O-enolate form and the other unit coordinates to the samarium atom by the carbonyl group. A comparison between 145 and the... 

SAMARIUM. [CAS 7440-19-9]. Chemical element symbol Sm, at. no. 62, at. wt. 150.35, fifth in the Lanthanide Series in the periodic table, mp 1,073°C, bp l,79l°C, density 7.520 g/cm3 (20 C). Elemental samarium has a rhombohedral crystal structure at 25DC. The pure metallic samarium is silver-gray in color, retaining a luster in dry air, but only moderately stable in moist air, with formation of an adherent oxide. When pure, the metal is soft and malleable, but must be worked and fabricated under an inert gas atmosphere. Finely divided samarium as well as chips from working are... 

Compound SmCos belongs to the hexagonal system, space group P6/mmm, with a = 498.9 pm and c = 398.1 pm. Its crystal structure, as shown in Fig. 10.5.1, consists of two different layers of atoms. One layer is composed of two kinds of atoms in the ratio of 1 2 for samarium to cobalt, with the Sm atoms arranged in a closed packed layer and the Co atoms at the center of each triangular interstice. This layer alternates with another layer consisting of only cobalt atoms. 

The complex SmCpj was synthesized by metal vapour reaction of samarium with Cs(CH3)5H as a green product or by desolvation of the red SmCpj 2THF by sublimation. The crystal structure of the complex SmCpj shows it to be decamethyl samarocene with bent metallocene disposition [138], The Cg-Sm-Cg angle of 140.1° is greater than 136.7 in the desolvated analogue. The Sm-C bond distance is reduced, 2.79(1) A compared to 2.86 (3) A and the structure of SmCpj is shown in Fig. 6.12. 

Figure 6.13 Crystal structure of Yb6( X3-OH)4( x,r -OC6H4OMe)i0(r -OC6H4OMe)2(OC6H4OMe)2 [33]. (Redrawn from J. Carretas et al., Synthesis and characterization of samarium, europium and ytterbium aryloxides. Crystal structure of [Yb6(0H)4(0C6H40Me)i4]-4THF, Journal of Alloys and Compounds, 376, 289-292, 2006.)...

Figure 9.15 ORTEP plot (upper) and unit-cell packing diagram of the complex [SmFe] [99]. (Reprinted with permission from B. Yan, and Z. Chen, Cyano-bridged aqua(A, A -dimethylacetamide)(cyanoiron)lanthanides from samarium, gadolinium, or holmium nitrate and potassium hexacyanoferrate crystal structures and magnetochemistry, Helvetica Chimica Acta, 2001, 84, 817-829 (Figures 1 and 2). Wiley-VCH Verlag GmbH Co. KGaA.)...

Yan, B. and Chen, Z. (2001) Cyano-bridged aqua(Ai,Ai-dimethylacetamide)(cyanoiron)lanthanides from samarium, gadolinium, or holmium nitrate and potassium hexacyanoferrate crystal structures and magnetochemistry. Helvetica ChimicaActa, 84, 817—829. 

The materials derived from YBa2Cu307 by replacing yttrium with other rare earth elements (lutetium, ytterbium, thulium, erbium, hohnium, dysprosium, gadolinium, europium, samarium, neodymium, lanthanum) are also superconductors, with r, s of 88 to 96 K. The crystal structures of RBa2Cu307 are almost the same as those of YBa2Cu307. The lattice constant is slightly different for the different ionic radii of the rare earth elements, and yet their chemical and physical properties are almost the same as those of YBa2Cu307. 

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