A ferrocene-modified nickel MOF: design, characterization, and catalytic application for the synthesis of 1,2-disubstituted benzimidazole scaffolds

Abstract

Herein, we have designed an innovative bimetallic metal–organic framework (MOF) derived from ferrocene (Fc) linkers as a potential heterogeneous catalyst. Initially, a nickel-based MOF (Ni-AIPA MOF) was synthesized from Ni(NO₃)₂·6H₂O and 5-aminoisophthalic acid (AIPA), followed by ferrocene-2-carbaldehyde (Fc-CHO) functionalization via a Schiff base reaction to afford an Fc-modified bimetallic Ni-Fc-AIPA MOF. The tailored bimetallic MOF was comprehensively characterized using FE-SEM, EDAX, P-XRD, FT-IR, TGA, BET, and XPS techniques, confirming its high crystallinity, appreciable porosity, excellent stability and efficient active sites. It was efficiently utilized as a heterogeneous catalyst for the synthesis of 1,2-disubstituted benzimidazoles in good yields via oxidative cyclization of ortho-phenylenediamine with benzaldehydes. The developed bimetallic MOF offers a promising and economical alternative to noble-metal catalysts for cyclization reactions and provides a practical platform for advancing ferrocene-integrated MOF systems in heterogeneous catalysis.