A highly stable metal–organic framework with cubane-like clusters for the selective oxidation of aryl alkenes to aldehydes or ketones

Abstract

Triazine derivatives, a class of electron-deficient π-conjugated molecules with high photochemical activity and excellent luminescent characteristics, have been utilized as a kind of electron-acceptor for the construction of molecular cages, luminescent and photochromic materials. In this paper, a novel and highly stable MOF with cubane-like clusters, [Co₄(SO₄)₃(F)₃(tpt)₂(tatb)] (1) (tpt = 2,4,6-tris-(4-pyridyl)-1,3,5-triazine, H₃tatb = 4,4′,4′′-(1,3,5-triazine-2,4,6-triyl)tribenzoic acid), has been successfully synthesized based on a triazine derivative, and possesses unprecedented sulfate- and fluoride-bridged cubane-type tetranuclear cobalt clusters and a 3D + 3D → 3D open framework. Compound 1 shows a rather high BET surface area and exhibits excellent thermal stability and high chemical stability in common solvents and even in acidic or basic solutions (in a pH range from 4 to 12). Moreover, catalytic measurements show that compound 1 is an excellent heterogeneous catalyst for the selective oxidation of aryl alkenes to aldehydes or ketones with conversions of 97%.