225096-56-0Relevant academic research and scientific papers
POLYMERIZATION CATALYSTS
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Paragraph 0130; 0149, (2017/10/13)
The present invention relates to processes for polymerizing unsaturated hydrocarbon monomers. The present invention also relates to a precatalyst having the structure of Formula (I): [in-line-formulae]M{C(SiHAlk2)3}3??(I),[/in-line-formulae] and to a catalyst comprising the structure of Formula (II): [in-line-formulae]MC(SiHAlk2)3X2??(II),[/in-line-formulae] and methods for preparation thereof.
Intermolecular β-hydrogen abstraction in ytterbium, calcium, and potassium tris(dimethylsilyl)methyl compounds
Yan, Kaking,Schoendorff, George,Upton, Brianna M.,Ellern, Arkady,Windus, Theresa L.,Sadow, Aaron D.
, p. 1300 - 1316 (2013/05/21)
A series of organometallic compounds containing the tris(dimethylsilyl) methyl ligand are described. The potassium carbanions KC(SiHMe2) 3 and {KC(SiHMe2)3TMEDA}2 are synthesized by deprotonation of the hydrocarbon HC(SiHMe2) 3 with potassium benzyl. {KC(SiHMe2)3TMEDA} 2 crystallizes as a dimer with two types of three-center-two-electron K-H-Si interactions: side-on coordination of SiH (∠K-H-Si = 102(2)) and more obtuse K-H-Si structures (∠K-H-Si ≈ 150). The divalent calcium and ytterbium compounds M{C(SiHMe2)3}2L (M = Ca, Yb; L = 2THF, TMEDA) are prepared from MI2 and 2 equiv of KC(SiHMe2)3. Low 1JSiH coupling constants in the NMR spectra, low-energy νSiH bands in the IR spectra, and short M-Si distances and small M-C-Si angles in the crystal structures suggest β-agostic interactions on each C(SiHMe2) 3 ligand. The IR assignments of M{C(SiHMe2) 3}2L (L = 2THF, TMEDA) are supported by DFT calculations. The compounds M{C(SiHMe2)3}2L react with 1 or 2 equiv of B(C6F5)3 to give the 1,3-disilacyclobutane {Me2SiC(SiHMe2)2} 2 and MC(SiHMe2)3HB(C6F 5)3L or M{HB(C6F5)3} 2L, respectively. In addition, M{C(SiHMe2) 3}2L compounds react with BPh3 to give β-H abstracted products. The compounds M{C(SiHMe2)3} 2THF2 react with SiMe3I to yield Me 3SiH and disilacyclobutane as the products of β-H abstraction, while M{C(SiHMe2)3}2TMEDA and Me3SiI form a mixture of Me3SiH and the alkylation product Me 3SiC(SiHMe2)3 in a 1:3 ratio.
Lewis acid-mediated β-hydride abstraction reactions of divalent M(C(SiHMe2)3)2THF2 (M = Ca, Yb)
Yan, KaKing,Upton, Brianna M.,Ellern, Arkady,Sadow, Aaron D.
supporting information; experimental part, p. 15110 - 15111 (2010/01/16)
(Chemical Equation Presented) The divalent calcium and ytterbium compounds M(C(SiHMe2)3)2THF2 contain A-agostic SiH groups, as determined by spectroscopy and crystallography. Upon thermolysis, HC(SiHMe2/su
