Heterometallic Ce-IV/ V-V Oxo Clusters with Adjustable Catalytic Reactivities

fleterometallic Celv/M oxo clusters are underexplored yet and can benefit from synergistic properties from combining cerium and other metal cations to produce efficient redox catalysts. Herein, we designed and synthesized a series of new Ce12V6 oxo clusters with different capping ligands: Ce12V6-S04 Ce12V6-0Ts (OTs: toluenesulfonic acid), and Ce12V6-NBSA (NBSA: nitrobenzenesulfonic acid). Single crystal X-ray diffraction (SCXRD) for all three ructures reveals a Ce12V6 cubane core formulated [Ce12(V0)6024]1.8+ with cerium on the edges of the cube, vanadyl capping the faces, and sulfate on the corners.While infrared spectroscopy (IR), ultraviolet visible spectroscopy (UV vis), electrospray ionization mass spectrometry (EST-MS), and proton nuclear magnetic resonance (1H NMR) proved the successful coordination of the organic musla,,,r,, 9:$simul., atGligands to the Cei2V6 core, liquid phase 51V NMR and small-angle X-ray scattering (SAXS) confirmed the integrity of the clusters in the organic solutions. Furthermore, functionalization of the Ce12V6 core with organic ligands both provides increased solubility in term of homogeneous application and introduces porosity to the assemblies of Ce12V6-0Ts and Ce12V6-NI3SA in term of heterogeneous application, thus allowing more catalytic sites to be accessible and improving reactivity as compared to the nonporous and less soluble Ce12V6-SO4. Meanwhile, the coordinated ligands also influenced the electronic environment of the catalytic sites, in turn affecting the reactivity of the cluster, which we probed by the elective oxidation of 2-chloroethyl ethyl sulfide (GEES). This work provides a strategy to make full use of the catalytic sites within a class of inorganic sulfate capped clusters via organic ligand introduction.

Automated summary

New Ce12V6 oxo clusters with different capping ligands were designed and synthesized, showing enhanced solubility and catalytic activity compared to the nonporous Ce12V6-SO4. The introduction of organic ligands improved the accessibility of catalytic sites and influenced the electronic environment, affecting the reactivity of the cluster. This study provides a strategy to fully utilize the catalytic sites within inorganic sulfate capped clusters through the introduction of organic ligands.