Abstract
During large-scale preparations of 2,6-dimesitylbenzoic acid, Mes2ArCO2H (Mes = 2,4,6-trimethylphenyl), a highly insoluble by-product precipitated and was isolated. The material formed in modest yield but significantly impacted the preparation of Mes2ArCO2H. The isolated product could be dissolved, with difficulty, in acetone, THF or pyridine. Crystallization under the evaporating solvents resulted in the isolation of three new compounds in relatively low yield. From pyridine the compound [Mes2ArCO2Li(H2O)(py)]2 was recovered. Recrystallization from THF gave (Mes2ArCO2H)(Mes2ArCO2)Li(THF)2, which has been shown to contain both neutral (benzoic acid) and anionic (benzoate) ligands. Finally, crystals of [Mes2ArCO2(H2O)Li(μ-OH2)(μ-O2CMes2Ar)Li(H2O)]2·2H2O were isolated from the acetone solution. These new solids were characterized using single crystal X-ray structural determinations.