Metal scavenging and catalysis by periodic mesoporous organosilicas with 2,2′‐bipyridine metal chelating ligands

• Published in: Applied organometallic chemistry Vol. 35; no. 10
• Main Authors: Waki, Minoru, Inagaki, Shinji
• Format: Journal Article
• Language: English
• Published: Chichester Wiley Subscription Services, Inc 01.10.2021
• Subjects: Catalysis; Catalysts; Chelation; Chemical synthesis; Chemistry; Copper; Coupling; Covalent bonds; heterogeneous catalyst; Inductively coupled plasma; metal scavenger; Metals; Palladium; periodic mesoporous organosilica; Reagents; Scavenging; Sonogashira–Hagihara coupling
• ISSN: 0268-2605; 1099-0739
• DOI: 10.1002/aoc.6341

A periodic mesoporous organosilica containing 2,2′‐bipyridine (BPy‐PMO) was assessed as a metal scavenger and heterogeneous catalyst. The functionalized PMO was synthesized based on a modified version of a previously reported procedure and showed a large surface area with crystal‐like pore walls and uniformly small particles. The small BPy‐PMOs (s‐BPy‐PMOs) exhibited efficient adsorption and removal of palladium (Pd2+) and copper (Cu2+) ions from THF solutions, as confirmed by inductively coupled plasma and UV/vis spectroscopy analyses. The removal efficiencies for Pd and Cu were determined to be 99.9% and 97.5%, respectively. This material was also used to scavenge residual Pd and Cu from reagent solutions following Sonogashira–Hagihara coupling, during which C–C bonds are generated based on catalysis by these metals. Moreover, Pd2+ supporting s‐BPy‐PMO was found to act as an efficient heterogeneous catalyst for the Sonogashira–Hagihara coupling reaction and could be easily separated from the reaction solution by simple filtration and reused. The periodic mesoporous organosilica containing 2,2′‐bipyridine (s‐BPy‐PMO) with small uniform particle was assessed as a metal scavenger and heterogeneous catalyst. The material exhibited efficient adsorption of Pd and Cu from THF solution. Moreover, Pd2+‐supporting BPy‐PMO (Pd@PMO) acted as an efficient heterogeneous catalyst for the Sonogashira–Hagihara coupling reaction and could be easily separated from the reaction solution by simple filtration and reused.