Ytterbium, cyclopentadienyl complexes

CjHjS, Thiophene, tetrahydro-gold complexes, 26 85-87 C4H,NO, 2-Propenamide, 2-methyl-nickel complex, 26 205 C4H1()02, Ethane, 1,2-dimethoxy-solvates of chromium, molybdenum, and tungsten carbonyl cyclopentadienyl complexes, 6 343 tungsten complex, 26 50 ytterbium complex, 26 22 C4H i02.NaC5H5, Ethane, 1,2-dimethoxy-compd. with cyclopentadienylsodium, 26 341... 

C4H 0., Ethane, 1,2-dimethoxy-, ytterbium complex, 26 22 solvates of chromium, molybdenum, and tungsten carbonyl cyclopentadienyl complexes, 26 343 tungsten complex, 26 50... 

Recrystallization of the linked cyclopentadienyl-anilido ytterbium(ll) complex [Me2Si(CsMe4)(NPh)]Yb(THF)3 from toluene/hexane yielded the less solvated complex [ Me2Si(CsMe4)(NPh) Ln(THF)]2 as brown crystals in 91% yield (Scheme 219). The compound forms a dimeric structure through an intermolecular Yb-Ph 7r-interaction. 

Organolanthanoide hydrides (1 11,1 8,215,221), cyclopentadienyl-ytterbium(ll) complexes (190) as well as the cocondensation products of lanthanoides with acetylenic derivatives (137,216,222) catalyze the hydrogenation of olefins and acetylenes. 

Cyclopentadienyl complexes of lanthanoids(II) are known for samarium, europium and ytterbium [1-24] (Table III.L) One compound of Nd(II) is claimed as well [25], but its exact structure and the valent state of the neodymium atom apparently needs additional proves. Samarium derivatives are isolated as tetrahydrofuranates Cp2Sm(THF). In the case of europium and ytterbium solvent-free complexes are obtained. 

A similar reaction between diphenyl ditellurium and bisfpentamethylcyclopentadienyl] diamineytterbium in toluene produced the ytterbium complex with one benzenetellurolate, one amine ligand, and two cyclopentadienyl groups in a pscudotetrahedral arrangement1. 

Roesky introduced bis(iminophosphorano)methanides to rare earth chemistry with a comprehensive study of trivalent rare earth bis(imino-phosphorano)methanide dichlorides by the synthesis of samarium (51), dysprosium (52), erbium (53), ytterbium (54), lutetium (55), and yttrium (56) derivatives.37 Complexes 51-56 were prepared from the corresponding anhydrous rare earth trichlorides and 7 in THF and 51 and 56 were further derivatised with two equivalents of potassium diphenylamide to produce 57 and 58, respectively.37 Additionally, treatment of 51, 53, and 56 with two equivalents of sodium cyclopentadienyl resulted in the formation of the bis(cyclopentadienly) derivatives 59-61.38 In 51-61 a metal-methanide bond was observed in the solid state, and for 56 this was shown to persist in solution by 13C NMR spectroscopy (8Ch 17.6 ppm, JYc = 3.6 2/py = 89.1 Hz). However, for 61 the NMR data suggested the yttrium-carbon bond was lost in solution. DFT calculations supported the presence of an yttrium-methanide contact in 56 with a calculated shared electron number (SEN) of 0.40 for the yttrium-carbon bond in a monomeric gas phase model of 56 for comparison, the yttrium-nitrogen bond SEN was calculated to be 0.41. 

Cationic lanthanide complexes of samarium and ytterbium, [Cp"Sm([18]-crown-6)][SmCp"3] 0.5C6H6 and [Gp"Yb([18]-crown-6)][Cp"]-3C6H6 [Cp" = 7]S-CsH3(SiMe3)2-l,3], have been prepared by the reaction between bis (cyclopentadienyl) lanthanide and [18]-crown-6 in benzene (Scheme 32).190... 

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