Supramolecular and heterometallic architectures based on [Fe(CN)6]3-metallotectons and diverse organic cations: Crystal structure, Hirshfeld surface analysis, spectroscopic and thermal properties

An assembly involving [Fe(CN)(6)](3-) metallotectons as building units and organic cations of different geometry has been envisioned in order to elaborate three hybrid supramolecules based on ionic H-bonds with the formula {(H-pip)(H-2-pip)[Fe(CN)(6)]}center dot 5H(2)O (1)SPS:refid:: e1 , {(H-amtaz)(3) [Fe(CN)(6)]1]}center dot 2H(2)O (2), {(H-mel)(4) [Fe(CN)(6)]F}center dot H2O (3) ([H-pip](+) = H-piperazine; [H-2-pip](2+) = H-2 -piperazine; [H-amtazr = H-4-amino-1.2.4-triazole;[H- mel](+): H-melamine and [H-gua](+) = H-guanidine) and one three-dimensional heterometallic network {(H-gua)(2)K[Fe(CN)(6)]} (4). The compounds have been prepared by the slow evaporation method and characterized by single-crystal X-ray diffraction, Energy Dispersive X-ray Spectroscopy analysis (EDX), and Raman IR spectroscopy with assignment from ab initio calculations. Single crystal X-ray diffraction reveals that 1-3 present supramolecular networks, while 4 belongs to the 3D heterometallic polymers group characterized by continuous tunnels containing [H-gua](+) cations. Based on different intermolecular hydrogen bonding (simple and chargesupported) and pi-stacking interactions, compounds 1-3 further assembled into 2D and 3D supramolecular frameworks. Water molecules in compounds 1 and 2 are encapsulated in nearly closed cavities while compound 3 is practically non-porous. The thermogravimetric analyses (TGA) show that these complexes possess appreciable thermal stability.