Catalytic properties of a cobalt metal–organic framework with a zwitterionic ligand synthesized in situ

Abstract

Herein we describe the high yield synthesis of a highly crystalline cobalt(II) MOF with a novel zwitterionic ligand made up of 3,3′,4,4′-BPTC and 1,4-cyclohexanediamine, obtained in situ during the hydrothermal synthesis. The compound with the molecular formula C₄₆H₃₈N₄O₁₄Co·2H₂O has a molecular mass of 965.7783 g mol⁻¹, a triclinic crystalline system (a = 5.86 Å, b = 9.28 Å, c = 19.92 Å, α = 83.93°, β = 88.01°, γ = 78.59), it is thermally stable up to 300 °C and presents structural stability before and after removing the solvent molecules from its pores. This novel material showed catalytic properties in an electrophilic substitution reaction of indoles and aldehydes allowing the syntheses of bis(indolyl)methanes in high yields under mild reaction conditions and can be reused at least once with the same catalytic activity.