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

Abstract 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 ]}∙5H 2 O (1) SPS:refid::e1, {(H-amtaz) 3 [Fe(CN) 6 ]}∙2H 2 O (2) , {(H-mel) 4 [Fe(CN) 6 ]F}∙H 2 O (3) ([H-pip] +  = H-piperazine; [H 2 -pip] 2+  = H 2 -piperazine; [H-amtaz] +  = 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 charge-supported) and π-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.