In Situ Carboxylate-Functionalized {Mo₁₂O₃₈}^4--Based Three-Dimensional Supramolecular Framework as a Copper-Triggered...

It is of great research value to develop an efficient and stable catalyst that can achieve the oxidation of alkenes to obtain epoxides, which can serve as a multifunctional intermediate with important commercial value. Based on this, a three-dimensional (3D) supramolecular framework H[Cu^I(H₃bdcbpy)₂(Mo₁₂O₃₈)(H₂O)] (1, H₄bdcbpy·2Cl = N,N'-bis(3,5-dicarboxybenzyl-4,4'-bipyridine·dichloride) was obtained from carboxylate-functionalized 1D coordination polymers, which were derived from an unusual in situ [Mo₁₂O₃₈]^4- cluster and Cu-electron-deficient carboxylate complex units. The catalytic performance of 1 in the epoxidation of alkenes using TBHP was examined, revealing its remarkable efficiency in the conversion of cis-cyclooctene, with a high conversion rate of 99% and an outstanding selectivity of 100%. Complex 1 exhibited higher catalytic activity than the unmodified H₄bdcbpy·2Cl, CuCl₂·2H₂O, and Na₂MoO₄·2H₂O, as well as the most previously reported polyoxometalate (POM)-based metal-organic complexes (POMOCs). Moreover, the reaction kinetics and mechanism of the catalytic reaction were explored using free radical trapping experiments and control experiments. The stability of catalyst 1 was also investigated.