Samarium complexes 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 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 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.)...

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... 

In a similar manner, treatment of anhydrous rare earth chlorides with three equivalents of lithium 1,3-di-ferf-butylacetamidinate (prepared in situ from di-fert-butylcarbodiimide, Bu -N=C=N-Bu , and methyllithium) afforded Ln[MeC (NBu )2]3 (Ln = Y, La, Ce, Nd, Eu, Er, Lu) in 57-72% isolated yields [6,7,26]. X-ray crystal structures of these complexes demonstrated monomeric formulations with distorted octahedral geometry around the lanthanide(III) ions (Eig. 3, Ln = La). The new complexes are thermally stable at >300°C, and sublime without decomposition between 180-220°C/0.05Torr. Other series of homoleptic lanthanide tris(amidinates) include the -cyclohexyl-substituted derivatives [RC(NCy)2]3Ln(THF)n (R = Me, Ln = Nd, Gd, Yb, n = 0 R = Ph, Ln = Nd, Y, Yb, n = 2). A sterically hindered homoleptic samarium(III) tris(amidinate), Sm[HC(NC6H3Pr 2-2,6)2]3, was obtained by oxidation of the corresponding Sm(II) precursor (cf.. Scheme 8) [6,7]. 

FIGURE 78 Syntheses of hexanuclear and octanuclear samarium cluster complexes and their reaction with dinitrogen to afford tetranuclear cluster species containing a N2 ligand derived from dinitrogen reduction (top). The crystal structures of the hexanuclear (bottom left) and octanuclear (bottom right) clusters are shown (redrawn after Ganesan et al 2001). 

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