Nanowire iron(III) coordination polymer based on 1,2,4-triazolo[1,5-a]pyrimidine and chloride ligands

• Published in: Polyhedron 2019-04, Vol.162, p.45-51
• Main Authors: Sabatino, Piera, D'Agostino, Simone, Isopi, Jacopo, Rubino, Simona, Marcaccio, Massimo, Girasolo, Maria Assunta
• Format: Article
• Language: English
• Subjects: 1,24-Triazolo[1,5-a]pyrimidine; Cyclic voltammetry; Scanning probe microscopy; Self-assembly; Solid state structure
• ISSN: 0277-5387
• DOI: 10.1016/j.poly.2019.01.049

The coordination polymer resulting from the molecular assembly of metal and ligands forms a nanowire structure, as evidenced by X-ray crystallography, DLS measurements and AFM imaging. DLS measurements confirm the presence of nano-aggregates in suspension, attributable to the coordination polymer structure retained in solution. Their solvated hydrodynamic dimensions are in agreement with AFM results in dry conditions for the structures self-assembled on mica. [Display omitted] The neutral ligand 1,2,4-triazolo[1,5-a]pyrimidine (tp) has been employed to prepare a new coordination compound of Fe(III), [FeCl3(tp)2]n (1). Compound 1 was investigated by single crystal X-ray diffraction and found to be a coordination polymer forming a ladder structure based on metal–ligand interactions, while H-bonding and aromatic interactions contribute to the supramolecular self-assembly into a 3D nanostructured material. The polymeric assembly is retained also in solution, where a metallo-supramolecular polymer based on coordinative metal–ligand binding is present, as shown by dynamic light scattering (DLS) measurements. The redox properties of the Fe(III) coordination polymer have also been investigated in different solvents and its nanowire structure has been assessed by Atomic Force Microscopy (AFM) imaging of the species deposited onto a freshly cleaved mica surface.