Nitrate-Anion-Induced Formation of a 2D Metal-Organic Framework with an Unconventional Kagomé Lattice Exhibiting Methanol-Mediated Ketone Catalysis.

Metal-organic frameworks (MOFs) with kagomé lattice are attractive for their unique physical and chemical properties, but little attention has been paid to their catalytic properties. Herein, we report a 2D MOF based on a phosphonato-amino-carboxylate ligand (NaHL), i. e., [Na0.33Co(L)(CH3OH)2](NO3)0.33 (2), which exhibits an unconventional kagomé lattice. The formation of this kagomé lattice is caused by the selective recognition of the NO3 - anion by the phenolato group of L2- as evidenced by theoretical calculations. Compound 2 can be utilized for the α-methoxymethylation and aminomethylation of aromatic ketones using methanol as a C1 source. Interestingly, compound 2 can be exfoliated in-situ into nanosheets with one-layer thickness under catalytic reaction conditions, which improves the catalytic efficiency. Based on the results of experiments and theoretical calculations, we proposed possible pathways for the catalytic reaction.