Two new self-assembled cadmium(II) metal-organic frameworks constructed of a flexible tripodal ligand: synthesis, structure, and thermal stability

Abstract

Two novel complexes, namely [Cd(L)(NO3)2]n (1) and {[Cd(L)(NO3)2](CH3CH2OH)}n (2) (L = 1,3,5-tris[1-(4-oxidroxypyridinium-methylene)]benzene) are synthesized solvothermally in different solvents. Single crystal and powder X-ray diffraction, infrared spectroscopy, thermogravimetry, 2D fingerprint plots, and Hirshfeld surface analyses are carried out for these complexes and their topology and thermal stability are also analyzed. Two complexes exhibit the same 2D interpenetrating structure formed by the ligand coordinated with Cd(II) ions. Due to the presence of ethanol molecules in complex 2, part of π⋯π stacking in complex 1 is blocked, resulting in new C—H⋯π and hydrogen bonding. This change makes the weak force stronger and forms a more stable framework. The result is that the thermal stability of 2 is higher than that of 1.