First copper(II)-cyclophosphato complex with macrocyclic N-donor ligand: Single crystal structure elucidation with Hirshfeld surface analysis, optical, electrochemical and antioxidant properties

• Published in: Journal of solid state chemistry 2018-07, Vol.263, p.1-10
• Main Authors: Hemissi, Hanène, Fezai, Ramzi, Mezni, Ali, Besbes-Hentati, Salma, Rzaigui, Mohamed
• Format: Article
• Language: English
• Subjects: 1D-polymeric complex; Antioxidant activities; Cyclam; Cyclotetraphosphate; Optical properties
• ISSN: 0022-4596; 1095-726X
• DOI: 10.1016/j.jssc.2018.04.004

From the system metal-cyclam-condensed phosphate is isolated the first complex of {(H3O+)2[Cu(II)(μ-P4O12)(cyclam)]}n(1). This complex was characterized by X-ray diffraction (XRD), spectroscopy (diffuse reflectance, UV–Vis and FT-IR) and thermal analysis (DTA/TGA). The solved molecular structure of 1 revealed one rare 1D-anionic polymeric copper(II)-complex, {[Cu(II)(μ-P4O12)(cyclam)]2-}n, involving two distinct ring ligands (cyclam / cyclotetraphosphate), in which a new coordination mode of the P4O124− was observed. The counterions (H3O+) ensure the connection between 1D-polymers by acting as donor in a strong "charge-assisted" hydrogen bonds with P4O12 rings leading to 2D-supramolecular frameworks arranged in -A-B-A- fashion. The 2D-supramolecular network is stabilized by O/N-H…O interactions whereas the van der Waals contacts play a key role in the consolidation of the 3D packing as verified by Hirshfeld surface analysis in combination with 2D fingerprint plots. The biochemical properties of 1 was also evaluated via DDPH, ABTS, hydroxyl radical scavengers and ferric reducing power (FRP) showing promising antioxidant activities which has been clarified by means of the cyclic voltammetric study. This paper presents the first example of a copper(II) complex incorporating simultaneously cylophosphate and chelating N-donor ligand bridges. The complex formulated as {(H3O+)2[Cu(II)(μ-P4O12)(cyclam)]}n exhibits one rare example of 1D-anionic polymer containing a new coordination mode of the P4O124−. Furthermore, the oxonium cations show a structure-directing effect by a strong "charge-assisted" hydrogen bonding and play a crucial role in building 2D-supramolecular layers in crystal structure. [Display omitted] •Crystal structure of the first copper(II)-cyclophosphato complex with macrocyclic ligand.•Complex features one rare example of 1D-anionic polymer coordination involving two mixed 8-/14- membered ring ligands.•Role of charge-assisted hydrogen bonds in stabilizing crystal lattice.•Intermolecular interactions in complex were quantified and analyzed by 3D Hirshfeld surfaces and 2D fingerprint plots.•Optical, electrochemical and antioxidant properties were also investigated.