Serendipitous discovery of (L)-valine mediated in situ formation of two-dimensional coordination polymer by tripodal ligand with transition metals

A new methodology for 2D coordination polymer formation has been reported by in situ amide bond cleavage of the ligand L at room temperature under a mild condition in the presence of aqueous pyridine. The ligand is formed by the coupling of (L)-valine with benzene-1,3,5-tricarboxylic acid (btcH(3)). The three amide bonds present on the tripodal ligand, easily break and forms 2D coordination polymer with btc(-3) as {[(btc)(py)(3)(H2O)(Co)(1.5)].(py)(H2O)(2)}(n) (1), {(btc)(0.66)(py)(3)(H2O)Ni}(n) (2), and {[(btc)(py)(3)Zn-1.5](H2O)(2)}(n) (3). The tripodal ligand L has been characterized by H-1 NMR, C-13 NMR, IR, and mass spectra and their corresponding coordination polymers 1, 2, and 3, respectively, have been characterized by single-crystal X-ray diffraction and thermogravimetric analysis.

Automated summary

A new methodology for the formation of 2D coordination polymers by in situ amide bond cleavage and ligand coupling has been reported. The coordination polymers were formed under mild conditions at room temperature and characterized by various techniques.