Synthesis, Characterization, and Magnetic Properties of a Series of Copper(II) Chloride Complexes of Pyridyliminebenzoic Acids. Issue 14 (17th April 2018)

• Record Type: Journal Article
• Authors: Buvaylo, Elena A.; Kokozay, Vladimir N.; Makhankova, Valeriya G.; Melnyk, Andrii K.; Korabik, Maria; Witwicki, Maciej; Skelton, Brian W.; Vassilyeva, Olga Yu.
• Is Part Of: European journal of inorganic chemistry. Issue 14(2018)
• Page Start: 1603
• Page End: 1619
• Publication Date: 2018-04-17
• Subjects: Copper -- N, O ligands -- Aminobenzoic acids -- Schiff bases -- X‐ray diffraction -- Structure elucidation -- Magnetic properties -- Density functional calculations; Chemistry, Inorganic -- Periodicals; Organometallic chemistry -- Periodicals; Bioinorganic chemistry -- Periodicals; Solid state chemistry -- Periodicals; 546
• DOI: 10.1002/ejic.201701391
• Languages: English
• ISSNs: 1434-1948

Abstract

Abstract : A series of Cu II halide complexes, Cu(HL1)Cl2 · CH3 OH (1 ), [Cu(L1)Cl]2 · H2 O (2 ), [Cu(HL2)Cl2 ]2 · 2DMF (3 ), [Cu(HL2)2 Cl] n Cl n · 2 n H2 O (4 ), and [Cu(L3)Cl] n (5 ), containing pyridyliminebenzoic acids HL1, HL2, and HL3 derived from o ‐, m ‐, and p ‐aminobenzoic acids, respectively, have been obtained as single crystals and characterized by elemental analysis, IR, EPR spectroscopy, magnetic measurements, and single‐crystal X‐ray diffraction techniques. The results obtained show the formation of molecular (1 ), dimeric (2, 3 ), and polymeric structures (4, 5 ) based on chloride (1 –4 ) and carboxylate bridges (5 ) with copper(II) ions in the square pyramidal geometry of varying degrees of distortion. In the case of2 and5 the ligand deprotonation was completely achieved even in the absence of a base. The closest Cu··· Cu separations are found in the crystal lattices of the polymer5 (3.33 Å) and dimers2 (3.35 Å) and3 (3.38 Å). The X‐band polycrystalline EPR spectra of1 –3 with typical axial patterns show no indication of exchange interactions between copper ions in the range 295–77 K. The observed rhombic features of the EPR spectra of4 arise from the coupling of g ‐tensors from differently oriented Cu II coordination polyhedra in the solid state. A characteristic spin‐triplet EPR spectrum of5 at 77 K was simulated by using the spin‐Hamiltonian parameters for S = 1, g x = 2.08, g y = 2.11, g z = 2.37 and the value of the zero‐field splitting parameter D of 0.137 cm –1 . Magnetic susceptibility measurements revealed antiferromagnetic (1 –3, 5 ) and ferromagnetic coupling (4 ) between the metal atoms at low temperatures. Theoretical methods were employed to provide additional insight into magnetic interactions in the studied compounds. Abstract : Five monomeric, dimeric, and polymeric Cu II complexes with α‐iminopyridine ligands have been used as platforms for detailed magnetostructural analysis of low‐dimensional Cu II molecular magnetic systems. Theoretical methods supported magnetic exchange pathways developed from the experimental data.