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Synthesis and Structures of the C 5 Me 4 SiMe 3 ‐Supported Polyhydride Complexes over the Full Size Range of the Rare Earth Series
Author(s) -
Nishiura Masayoshi,
Baldamus Jens,
Shima Takanori,
Mori Kyouichi,
Hou Zhaomin
Publication year - 2011
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.201002998
Subject(s) - hydrogenolysis , lanthanide , chemistry , toluene , rare earth , crystallography , yield (engineering) , metal , crystal structure , homoleptic , stereochemistry , medicinal chemistry , ion , materials science , catalysis , organic chemistry , mineralogy , metallurgy
Abstract The acid–base reaction of [Ln(CH 2 SiMe 3 ) 3 (thf) 2 ] with Cp′H gave the corresponding half‐sandwich rare earth dialkyl complexes [(Cp′)Ln(CH 2 SiMe 3 ) 2 (thf)] ( 1‐Ln : Ln=Sc, Y, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu; Cp′=C 5 Me 4 SiMe 3 ) in 62–90 % isolated yields. X‐ray crystallographic studies revealed that all of these complexes adopt a similar overall structure, in spite of large difference in metal‐ion size. In most cases, the hydrogenolysis of the dialkyl complexes in toluene gave the tetranuclear octahydride complexes [{(Cp′)Ln(μ‐H) 2 } 4 (thf) x ] ( 2‐Ln : Ln=Sc, x =0; Y, x =1; Er, x =1; Tm, x =1; Gd, x =1; Dy, x =1; Ho, x =1) as the only isolable product. However, in the case of Lu, a trinuclear pentahydride [(Cp′) 2 Lu 3 (μ‐H) 5 (μ‐CH 2 SiMe 2 C 5 Me 4 )(thf) 2 ] ( 3 ), in which the CH activation of a methyl group of the Me 3 Si unit on a Cp′ ligand took place, was obtained as a major product (66 % yield), in addition to the tetranuclear octahydride [{(Cp′)Lu(μ‐H) 2 } 4 (thf)] ( 2‐Lu , 34 %). The use of hexane instead of toluene as a solvent for the hydrogenolysis of 1‐Lu led to formation of 2‐Lu as a major product (85 %), while a similar reaction in THF yielded 3 predominantly (90 %). The tetranuclear octahydride complexes of early (larger) lanthanide metals [{Cp′Ln(μ‐H) 2 } 4 (thf) 2 ] ( 2 , Ln=La, Ce, Pr, Nd, Sm) were obtained in 38–57 % isolated yields by hydrogenolysis of the bis(aminobenzyl) species [Cp′Ln(CH 2 C 6 H 4 NMe 2 ‐ o ) 2 ], which were generated in‐situ by reaction of [Ln(CH 2 C 6 H 4 NMe 2 ‐ o ) 3 ] with one equivalent of Cp′H. X‐ray crystallographic studies showed that the fine structures of these hydride clusters are dependent on the size of the metal ions.