Influence of the Steric Demand of the 2,4,6‐Trialkylphenyl Substituents on the Structures and Reactivity of Diarylzinc

The Grignard reaction of 2,4,6‐tri( tert‐ butyl)phenylmagnesium bromide with zinc dichloride in THF yields monomeric bis[2,4,6‐tri( tert‐ butyl)phenyl]zinc ( 1 ). Due to the steric demand of the tert ‐butyl groups 1 has a bent CZnC moiety and the boat‐shaped aryl groups are in a staggered conformation. After the transmetallation of 1 with cesium in a solvent mixture of 1,2‐dimethoxyethane (DME) and toluene (1,2‐dimethoxyethane‐ O , O ′)cesium [2,4,6‐tri( tert‐ butyl)phenolate] ( 2 ) is isolated. A polymeric structure is formed in the crystalline state by linkage of these molecules via a Cs‐O bond of the phenolate oxygen atoms and a η 6 ‐coordination of the aryl moiety of another molecule to the cesium cations. Furthermore, in the solid state the cesium cation completes his coordination sphere by bonds to a bidentate ether molecule and by close contacts to a tert‐ butyl group of a neighboring molecule.