From Bidentate Gallium Lewis Acids to Supramolecular Complexes.

Authors :: Horstmann J
Hyseni M
Mix A
Neumann B
Stammler HG
Mitzel NW
Source :: Angewandte Chemie (International ed. in English) [Angew Chem Int Ed Engl] 2017 May 22; Vol. 56 (22), pp. 6107-6111. Date of Electronic Publication: 2017 Apr 18.
Publication Year :: 2017
Abstract: Bidentate gallium Lewis acids were prepared by the reaction of diethynyldiphenylsilane with neat trimethyl- or triethylgallium. Bis[(dimethylgallyl)ethynyl]diphenylsilane (1) and diethylgallyl derivative 2 were characterized as Et <subscript>2</subscript> O or pyridine adducts by NMR spectroscopy; 2⋅2Py was isolated. Lewis acids 1 and 2 form host-guest adducts with bidentate nitrogen bases, but defined cyclic 1:1 adducts are only formed between 1 and bases with matching N⋅⋅⋅N distances: 4,4'-dimethyl-3,3'-bipyridinylacetylene (3), bis[(pyridin-3-yl)ethynyl]diphenylsilane (4), and bis[(2-methylpyridin-5-yl)ethynyl]diphenylsilane (5). The structures of adducts 1⋅3, 1⋅4, and 1⋅5 were established by X-ray diffraction experiments. 2⋅2Py reacts with DABCO to afford polymeric (DABCO-2-) <subscript>n</subscript> .<br /> (© 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)