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Yttrocene Chloride and Methyl Complexes with Variously Substituted Cyclopentadienyl Ligands: Synthesis, Characterization, and Reactivity toward Ethylene
Author(s) -
Fridrichová Adéla,
Varga Vojtech,
Pinkas Jiří,
Lamač Martin,
Růžička Aleš,
Horáček Michal
Publication year - 2016
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.201600390
Subject(s) - chemistry , cyclopentadienyl complex , reactivity (psychology) , ethylene , chloride , medicinal chemistry , nuclear magnetic resonance spectroscopy , lithium (medication) , crystal structure , potassium , ionic bonding , crystallography , catalysis , stereochemistry , ion , organic chemistry , medicine , alternative medicine , pathology , endocrinology
The reaction of YCl 3 · 3.5THF with 1 equiv. of Li(C 5 Me 4 SiMe 3 ) afforded in high yield the ionic complex [Li(thf) 4 ] + {[(η 5 ‐C 5 Me 4 SiMe 3 )YCl 2 ] 4 (µ 4 ‐Cl)} – ( 1 ). The molecule of 1 consists of the tetranuclear anion {[(η 5 ‐C 5 Me 4 SiMe 3 )YCl 2 ] 4 (µ 4 ‐Cl)} – compensated with [Li(thf) 4 ] + in the solid state. Reactions of compound 1 with selected lithium and potassium cyclopentadienides resulted in the formation of yttrocene chloride complexes [(η 5 ‐C 5 Me 4 SiMe 3 )Y(L)(µ‐Cl) 2 M(thf) 2 ] [M = Li, L = η 5 ‐C 5 H 5 ( 2 ); M = Li, L = η 5 ‐C 5 Me 5 ( 3 ); M = Li, L = η 5 ‐C 5 Me 4 SiMe 2 H ( 4 ); M = K, L = η 5 ‐C 5 Me 4 CH 2 Ph ( 5 )]. Yttrocene chloride complexes 2 – 5 underwent methylation reactions to give yttrocene methyl complexes [(η 5 ‐C 5 Me 4 SiMe 3 )Y(L)(µ‐Me) 2 Li(thf) 2 ] [L = η 5 ‐C 5 H 5 ( 6 ); L = η 5 ‐C 5 Me 5 ( 7 ); L = η 5 ‐C 5 Me 4 SiMe 2 H ( 8 ); L = η 5 ‐C 5 Me 4 CH 2 Ph ( 9 )]. The products of all these reactions were characterized by NMR and IR spectroscopy, and 2 – 5 were further studied by ESI mass spectrometry. The molecular structures of 1 and 4 were determined by single‐crystal XRD. The methyl‐bridged complexes 6 – 9 were tested as homogeneous catalysts for ethylene polymerization in the absence of cocatalysts.