Synthesis and Structural Studies on [Mg3(O2CC⋮CSiMe3)6(HMPA)4]: Mechanistic Implications for the Formation of the μ4-η4 Bonding Type in Carbamato-Bridged Mg6 Cage Compounds
journal contributionposted on 16.02.2002, 00:00 by Kuo-Ching Yang, Chung-Cheng Chang, Charng-Sheng Yeh, Gene-Hsiang Lee, Yu Wang
The insertion reaction of CO2 with Mg(C⋮CSiMe3)2 was characterized by NMR spectroscopic studies to give a cage compound [Mgn(O2CC⋮CSiMe3)2n·(THF)m], 1a, and the addition of HMPA/THF (HMPA = hexamethylphosphoramide) to solutions of 1a produces a trimeric compound, [Mg3(O2CC⋮CSiMe3)6(HMPA)4], 1b. X-ray diffraction studies of this showed 1b to contain a completely centrosymmetric linear array of magnesium atoms linked with μ2-η2- and μ2-η3-O2CC⋮CSiMe3. It was found to be a key compound in the mechanism leading to the formation of μ4-η4 bonding in carbamato-bridged Mg6 cage compounds.