244236-10-0Relevant academic research and scientific papers
Coordination of allenyl/propargyl group to samarium(III): The first crystal structures of η3-allenyl and η1-propargyl lanthanide complexes
Ihara, Eiji,Tanaka, Motomi,Yasuda, Hajime,Kanehisa, Nobuko,Maruo, Tatsuya,Kai, Yasushi
, p. 26 - 32 (2007/10/03)
The synthesis and crystal structures of samarium complexes incorporating bridged Cp′-SiMe2-allenyl/propargyl ligands [Cp′ = (Me3Si)2(C5H2)] are described. The reaction of a dilithium salt of [(Me3Si)2(C5H3)]SiMe 2CH2C≡CSiMe3 (1a) with SmCl3 yielded an η3-allenyl complex {[(Me3Si)2(C5H2)]SiMe 2(η3-C=C=C[H]SiMe3)}SmCl3Li 2(TMEDA)2 (2a) (TMEDA = N,N,N′,N′-tetramethylethylenediamine). On the other hand, the reaction of a dilithium salt of a Ph3Si substituted ligand [(Me3Si)2(C5H3)]SiMe 2CH2C≡CSiPh3 (1b) with SmCl3 yielded an η1-propargyl complex {[(Me3Si)2(C5H2)]SiMe 2(η1-CHC≡CSiPh3)}-Sm(TMEDA)[Cl 2Li(TMEDA)] (2b). A conversion of bonding mode from η1-propargyl to η3-allenyl was observed when 2b was treated with (Me3Si)3CLi/LiI to give an η3-allenyl complex {[(Me3Si)2(C5H2)]SiMe 2(η3-CH=C=CSiPh3)}SmI2Li(TMEDA) (3b). The same structural conversion was also observed when 2b was treated with (Me3Si)2CHLi to give an anionic ate complex ({[(Me3Si)2(C5H2)]SiMe 2(η3-CH=C=CSiPh3)}SmCl[CH(SiMe 3)2])[Li(TMEDA)2] (4b), which had the η3-allenyl bonding structure. The structures of these four complexes (2a, 2b, 3b, and 4b) were revealed by X-ray crystallography. These are the first examples of the structural characterization of η3-allenyl and η1-propargyl lanthanide complexes.
