Design, Synthesis and Characterization of Nickel‐Functionalized Covalent Organic Framework NiCl@RIO‐12 for Heterogeneous Suzuki–Miyaura Catalysis

Abstract

As eries of nickel-decorated covalento rganic frameworks, NiCl@RIO-12, were prepared using the post-synthetic modification strategy,t hat is, by reactingN iCl 2 with pristine RIO-12 under alkaline conditions. Interestingly,t hey retained their crystallinity andt he amount of nickel incorporated could be tuned from 3.6 to 25 wt %a ccording to the reaction conditions. The incorporation of ah igher amount of nickel in NiCl@RIO-12 consistently led to al ower Brunauer-Emmett-Teller surfacea rea. Additionally,n oa gglomeration of nickel particles was found and ar elativelyh omogeneous dispersion of nickel could be ascertained by SEM and TEM-EDS. The paramagnetic material exhibited promising catalytic activity in Suzuki-Miyaura cross-couplingu nder microwave heating. Thus,N iCl@RIO-12 notably demonstrated good thermal stability and its recyclability showed no substantial loss of activity after 3cycles.

A Carbocationic Triarylmethane‐Based Porous Covalent Organic Network

“…Another possibility is that the relatively weak diffraction signals from the framework are attenuated by the presence of species with higher scattering factor (chlorine) randomly oriented within the pore structure, which dominates the scattering. This was observed in similar cases, where the framework is indeed crystalline, but its corresponding diffraction signals are suppressed by the heavier species confined in their pores [23–25] …”

“…This was observed in similar cases, where the framework is indeed crystalline, but its corresponding diffraction signals are suppressed by the heavier species confined in their pores. [23][24][25] Pararosaniline hydrochloride can be in equilibrium between its ionized and neutral forms (Scheme 1), depending on the solvent. Its ionic form is favoredi np olar protic solvents.…”

Small-angle X-ray scattering as a multifaceted tool for structural characterization of covalent organic frameworks

“…Additionally, since this probable Guinier shoulder is only notable for RIO-12 in the SAXS range, it suggests that RIO-12's grain is smaller than the other microporous materials' grains. Additionally, while investigating a sample of RIO-12 containing 3.6 wt% of nickel in our group's recent study (Maia et al, 2020), high-resolution transmission electron microscopy (HRTEM) showed a compelling result. The micrograph of the modified material ( Fig.…”

Construction of the Copper‐Functionalized Covalent Organic Framework Used as a Heterogeneous Catalyst for Click Reaction

“…In addition, Zhang research group established a Cu@PI‐COF heterogeneous catalyst, which was highly stable and can be recycled 8 times in Chan‐Lam coupling reaction of aryl borate without loss of the high catalytic activity [26] . Renata et al [27] also developed a Ni‐doped RIO‐12 COF hybrid for organic coupling reactions and the hydroxyl groups of α‐imine‐phenol in the RIO‐12 COF can coordinate with Ni ion to form a catalytically active Ni‐COF complex.…”