1030834-22-0Relevant academic research and scientific papers
Rare-earth-metal mixed hydride/aryloxide complexes bearing mono(cyclopentadienyl) ligands. synthesis, CO2 fixation, and catalysis on copolymerization of CO2 with cyclohexene oxide
Cui, Dongmei,Nishiura, Masayoshi,Tardif, Olivier,Hou, Zhaomin
, p. 2428 - 2435 (2008)
Hydrogenolysis of mono(cyclopentadienyl)-ligated rare-earth-metal bis(alkyl) complexes Cp′Ln(CH2SiMe3) 2(THF) (Ln = Y (1a), Dy (1b), Lu (1c); Cp′ = C 5Me4SiMe3) with PhSiH3 afforded the mixed hydride/alkyl complexes [Cp′Ln(μ-H)(CH2SiMe 3)(THF)]2 (Ln = Y (2a), Dy (2b), Lu (2c)). The overall structure of complexes 2a-c is a C2-symmetric dimer containing a planar symmetric Ln2H2 core at the center of the molecule. Deprotonation of ArOH (Ar = C6H2-tBu 2-2,6-Me-4) by the metal alkyl group of 2a-c led to formation of the mixed hydride/aryloxide derivatives [Cp′Ln(μ-H)(OAr)]2 (Ln = Y (3a), Dy (3b), Lu (3c)), which adopt the dimeric structure through hydride bridges with transaccommodated terminal aryloxide groups. Complexes 3a-c swiftly reacted with CO2 to generate the mixed formate/carbonate complexes [Cp′Ln(μ-η1:η1-O2CH)(μ- η1:η1-O2COAr)]2 (Ln = Y (4a), Dy (4b), Lu (4c)). The two Cp'Ln fragments in these complexes are bridged by the formate and carbonate species, respectively, to form two square-pyramidal geometries around the metal centers. Furthermore, complexes 3a-c initiated the copolymerization of CO2 and cyclohexene oxide (CHO) under mild conditions to afford polymers with modest molecular weights and high carbonate linkages (92-99%).
