Stable "Inverse" Sandwich Complex with Unprecedented Organocalcium(I): Crystal Structures of [(thf)(2)Mg(Br)-C6H2-2,4,6-Ph-3] and [(thf)(3)Ca{mu-C6H3-1,3,5-Ph-3}Ca(thf)(3)]

作者：Krieck Sven; Goerls Helmar; Yu Lian; Reiher Markus^*; Westerhausen Matthias

来源：Journal of the American Chemical Society, 2009, 131(8): 2977-2985.

DOI：10.1021/ja808524y

The reaction of bromo-2,4,6-triphenylbenzene with activated magnesium in THF yielded the Grignard reagent [(thf)(2)Mg(Br)-C6H2-2,4,6-Ph-3] (1) with a Mg-C bond length of 214.8(3) pm. A similar reaction of bromo-2,4,6-triphenylbenzene with activated calcium led to an "inverse" sandwich complex [(thf)(3)Ca{mu-C6H3-1,3,5-Ph-3}Ca(thf)(3)] (2) with the calcium atoms on opposite sides of the central arene ring showing small Ca-Ca' and Ca-C distances of 427.9(3) and 259.2(3) pm. This extremely air- and moisture-sensitive complex exhibits thermochomic and solvatochromic behavior. It is paramagnetic with spin of S = 1 (triplet) with an ESR resonance at g = 2.0023. Quantum chemical calculations shed light on the bonding situation in this very unusual dinuclear Ca(I) compound.

• 出版日期2009-3-4