Mono- and binuclear copper(II) complexes with different structural motifs and geometries: Synthesis, spectral characterization, DFT calculations and superoxide dismutase enzymatic activity. (1st August 2022)

• Record Type: Journal Article
• Authors: Patel, Satish K.; Patel, Ram N.; Patel, Neetu; Patel, Abhay K.; Herrero, S.; Choquesillo-Lazarte, D.; Butcher, R.J.
• Is Part Of: Polyhedron. Volume 222(2022)
• Publication Date: 2022-08-01
• Subjects: Single crystal X-ray analysis -- FTIR and UV–vis spectra -- Epr spectra -- Magnetic measurement -- Hirshfeld surface analysis -- DFT calculations -- Superoxide dismutase activity; Chemistry, Inorganic -- Periodicals; Chimie inorganique -- Périodiques; Organometaalverbindingen; Anorganische chemie; 546.05
• DOI: 10.1016/j.poly.2022.115913
• Languages: English
• ISSNs: 0277-5387

Abstract

Graphical abstract: Four new copper(II) mono- and binuclear complexes, [Cu(HL)(ClO4 )(H2 O)]CH3 OH (1), [Cu(HL)(DMF)](ClO4 )CH3 OH (2), [Cu2 (HL)2 (pyrazine)](ClO4 )2 (3) and [Cu2 (HL)2 (4, 4-bipy)(ClO4 )2 ]2H2 O (4) (HL = 4-bromo-2-(pyridine-2-ylhydrazonomethyl)-phenol, 4, 4-bipy = 4, 4-bipyridyl) have been synthesized and characterized by elemental analysis, FTIR, UV–vis and electron paramagnetic resonance (Epr) spectroscopy. Molecular structures of all complexes have been obtained using single crystal X-ray analysis. The geometry of copper(II) in 1 is distorted square pyramidal and distorted square planar in 2 . In binuclear complexes each copper(II) centre has distorted square planar and distorted square pyramidal geometry in 3 and 4, respectively. The complexes 1 –4 possess the self-assembled supramolecular structures via different molecular interactions (hydrogen bondings, CH ⋯ π and π ⋯ π stacking interactions). The possible intermolecular interactions were explored using 3D Hirshfeld surface and related 2D fingerprint plots, spectroscopic properties were studied using UV–visible and electron paramagnetic resonance techniques. Abstract: Several new copper(II) mono- and binuclear complexes, [Cu(HL)(ClO4 )(H2 O)]CH3 OH (1), [Cu(HL)(DMF)](ClO4 )CH3 OH (2), [Cu2 (HL)2 (pyrazine)](ClO4 )2 (3) and [Cu2 (HL)2 (4, 4-bipy)(ClO4 )2 ]2H2 O (4) (HL = 4-bromo-2-(pyridine-2-ylhydrazonomethyl)-phenol, 4, 4-bipy = 4, 4-bipyridyl) have been synthesized and characterized by elemental analysis, FTIR, UV–vis and electron paramagnetic resonance (Epr) spectroscopy. Molecular structures of all complexes have been obtained using single crystal X-ray analysis. The geometry of copper(II) in 1 is distorted square pyramidal and distorted square planar in 2 . In binuclear complexes each copper(II) centre has distorted square planar and distorted square pyramidal geometry in 3 and 4, respectively. The complexes 1 –4 possess the self-assembled supramolecular structures via different molecular interactions (hydrogen bondings, CH ⋯ π and π ⋯ π stacking interactions). The possible intermolecular interactions were explored using 3D Hirshfeld surface and related 2D fingerprint plots, spectroscopic properties were studied using UV–visible and electron paramagnetic resonance techniques. Optimized geometry, frontier molecular orbital (FMO) and natural bond order (NBO) analysis were performed using density functional theory (DFT) calculations. To predict the chemical reactivity of complexes some global reactivity descriptors (chemical potential μ, electronegativity χ, hardness η and electrophilicity index ω ) have been evaluated using DFT. The low temperature magnetic susceptibility measurements of binuclear complexes have been obtained predicts the magnetic exchange coupling value (J) by variable temperature measurements. The magnetic exchange coupling value (J) obtained are −8.1 and −2.4 cm −1 for 3 and 4, respectively. The superoxide dismutases (SOD) of all complexes were measured using NBT assay method. The complexes show moderate superoxide dismutase (SOD) mimetic activity.