Ligand-Substrate Self-Sorting in Silica-Encased Rh-Nanopetals as Model Catalyst for Hydroformylation of Arylalkenes

Abstract

Self-regulated ligand-substrate interaction with the metal center is fundamental to enzymes and homogeneous complexes, yet similar phenomena in heterogeneous systems remain underexplored. Simultaneous control of reactivity and selectivity becomes challenging due to the competitive molecular-adsorption-mediated blocking of reaction-sites. Here, we address this dichotomy by introducing the concept of ligand-substrate self-sorting (LSS) in a silica-encased Rh-nanopetals (Rh-NPLs) model platform for hydroformylation of alkene. We synthesized different stages of Rh-NPLs (bud, bloomed flower and flower-in-book) inside a bilayer silica-encase. 2D-constrained Rh growth establishes controllable intimacy with the silica overlayer while availing molecular size interfacial spaces. Optimal design endows a well-orchestrated microenvironment to avoid conflicting ligand-substrate adsorption. Remarkably, LSS phenomena lead to high hydroformylation regioselectivity (>90%) without compromising the catalyst activity (>99% yield). The present work demonstrates the nanoscale material design capability, influencing the multimolecular dynamic events with implications toward sustainable chemical synthesis.