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Homolysis of the Ln−N (Ln = Yb, Eu) Bond − Synthesis, Structure, and Catalytic Activity of Ytterbium( II ) and Europium( II ) Complexes Having (Dimethylamino)propyl‐ and (Dimethylamino)ethyl‐Functionalized Indenyl Ligands
Author(s) -
Sheng Enhong,
Zhou Shuangliu,
Wang Shaowu,
Yang Gaosheng,
Wu Yongyong,
Feng Yan,
Mao Lili,
Huang Zixiang
Publication year - 2004
Publication title -
european journal of inorganic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.667
H-Index - 136
eISSN - 1099-0682
pISSN - 1434-1948
DOI - 10.1002/ejic.200400077
Subject(s) - europium , chemistry , toluene , lanthanide , homolysis , medicinal chemistry , catalysis , ytterbium , yield (engineering) , stereochemistry , ion , organic chemistry , physics , materials science , optoelectronics , doping , metallurgy , radical
We have synthesized a new series of ytterbium( II ) and europium( II ) complexes by tandem silylamine elimination/homolysis of Ln−N (Ln = Yb, Eu) bonds. The interaction of 2 equiv. of C 9 H 7 CH 2 CH 2 CH 2 NMe 2 ( 1 ) with [(Me 3 Si) 2 N] 3 Ln(μ‐Cl)Li(THF) 3 (Ln = Yb, Eu) in toluene under reflux produced lanthanide( II ) complexes [(η 5 :η 1 ‐C 9 H 6 CH 2 CH 2 CH 2 NMe 2 ) 2 Ln] [Ln = Yb ( 2 ), Eu( 3 )] in 67 and 74% yields, respectively. Treatment of 2 equiv. of Me 2 Si(Me 2 NCH 2 CH 2 C 9 H 6 )(NH t Bu) with [(Me 3 Si) 2 N] 3 Eu(μ‐Cl)Li(THF) 3 in toluene at 80 °C afforded a europium( II ) complex [η 5 :η 1 ‐Me 2 Si(Me 2 NCH 2 CH 2 C 9 H 5 )(NH t Bu)] 2 Eu·(OC 4 H 8 ) 0.5 ( 4 ) in 46% yield. The interaction of 2 equiv. of Me 2 NCH 2 CH 2 C 9 H 6 SiMe 3 with [(Me 3 Si) 2 N] 3 Eu(μ‐Cl)Li(THF) 3 produced a europium( II ) compound [η 5 :η 1 ‐(Me 2 NCH 2 CH 2 C 9 H 5 SiMe 3 )] 2 Eu ( 5 ) in 49% yield. Treatment of 2 equiv. of Me 2 NCH 2 CH 2 C 9 H 7 with [(Me 3 Si) 2 N] 3 Eu(μ‐Cl)Li(THF) 3 in toluene gave a europium( II ) complex (η 5 :η 1 ‐Me 2 NCH 2 CH 2 C 9 H 6 ) 2 Eu ( 6 ) in 57% yield. All the compounds were fully characterized by spectroscopic methods and elemental analyses. The structures of the complexes 4 , 5 , and 6 were determined by single‐crystal X‐ray analyses. The catalytic activities of organometallic complexes were examined; we found that all of the complexes can function as single‐component MMA polymerization catalysts with good activity. We studied the effects of solvent and temperature on the catalytic activities and the stereochemistries of the polymers. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)