Triazoles synthesis using nanocatalyst triazine–pyrimidine-modified cobalt-based metal–organic frameworks

This research introduces a recyclable and environmentally friendly catalyst, Co(BDC-NH₂)-TA-PY, for the efficient synthesis of triazoles <i>via</i> the reaction of benzaldehydes, nitromethane, and sodium azide. The synthesis of Co(BDC-NH₂)-TA-PY was carried out through the post-synthetic modification of Co(BDC-NH₂), incorporating triazine-pyrimidine (TA-PY) functional groups. The key advantage of this catalyst lies in its dual functionality: the Lewis acidic sites of the Co(BDC-NH₂) metal-organic framework (MOF) are complemented by the Brønsted basic sites of the triazine and pyrimidine groups. This study represents the first example of a post-synthetic modification of the Co(BDC-NH₂) metal-organic framework (MOF) by integrating triazine and pyrimidine functional groups, which significantly enhanced its catalytic performance. The abundant TA-PY ligand increased the catalytic activity from 42% to 94%. Co(BDC-NH₂) nanocrystals were successfully synthesized and characterized, exhibiting a highly crystalline structure. Following the post-synthetic modification to synthesize Co(BDC-NH₂)-TA-PY, the catalyst retained its uniform morphology, ensuring consistent structural integrity. Furthermore, the structural integrity, morphology, and chemical composition of the reused Co(BDC-NH₂)-TA-PY were thoroughly examined, revealing no significant differences between the fresh and reused catalysts. These results highlight the potential of functionalized cobalt-based metal-organic frameworks as versatile and sustainable catalysts for broader organic reactions.