Antiferromagnetic Coupling In A (μ-Hydroxo)(μ-Pyrazolato)Dicopper(II) Complex. Synthesis, Crystal Structure, Magnetic Properties, And Theoretical Studies

Abstract

Binuclear Copper(II) Complex, Super-Exchange Interactions, Antiferromagnetic Coupling Preparation, crystal structure and magnetic properties of a 3,5-dimethylpyrazolate bridged binuclear copper(II) complex [Cu2(L')(3,5 prz)] (L1 = l,3-Bis(2-hydroxy-l-napthylideneamino)propan-2-ol) (1) are reported. Variable-temperature magnetic susceptibility measure ments for a powdered sample of the complex were carried out in the temperature range 5 -350 K and analysed to obtain values of the parameter J in the exchange Hamiltonian H = -2JS\ S2. In the dicopper(II) complex [Cu2(L2)(3,5 prz)], (L2 = l,3-Bis(2-hydroxy-5-chlorosalicylideneamino)propan-2-ol) (2) reported recently the antiferromagnetic interaction is much less than that of 1 (-27 = 440 cm-), as result which is difficult to explain in terms of structural factors on the basis of widely accepted criteria. The differences in the magnetic behaviour now have been rationalized using the "ligand orbital complementary" concept.

Structure, spectroscopic, and magnetic properties of copper(II) dinuclear complex with μ-hydroxo and μ-pyrazolato bridges

“…The geometry of the ligand implies the formation of polynuclear [M(pz) 2 ] n [1,2] and low-molecular weight di- [3][4][5][6][7][8][9], tri- [10,11], and tetranuclear [12][13][14] complexes with copper(II). Although there are many examples of binuclear copper(II) complexes with one bridging pyrazolate group and alcoholate or phenolate as another bridging group, [3][4][5][6][7][8][9] discrete binuclear copper(II) complexes with both pyrazolate and hydroxide bridges are unknown. It is worth to notice that cyclic trinuclear compounds with l 3 -OH [10,11] were described.…”

“…Strong antiferromagnetic coupling is usually observed for the dinuclear copper(II) complexes in which pyrazolate and oxygen (from alcoholate or phenolate group) are bridging ligands [3][4][5][6][7][8][9]29,30]. The Cu(II)-Cu(II) distance in those complexes exceed 3.35 A A, values of Cu-O-Cu angle are located in 121-127°and j2J j values fall into the region of 300-600 cm À1 , when ligands provide N 2 O 2 donor sets [3,4,8,9,29,30]. In those cases the observed magnetic properties were interpreted in the terms of countercomplementary interaction of pyrazole bridge toward the antiferromagnetism effected by the alkoxide/phenoxide bridge.…”

The synthesis, characterization and antibacterial activities of dinuclear Ni(II), Cu(II) and Fe(III) Schiff base complexes

“…Schiff base was prepared as recorded by H. Kara et al [9]. The metal complexes of Schiff base were syn thesized by the addition of hot solution (40°C) of the metal chlorides in 25 mL methanol to the hot solution (40°C) of ligand (50 mmol) in the same solvent (25 mL) in 1 : 1 molar ratio.…”

“…The metal complexes derived from dinucleating ligands also have applications in bioinorganic chemistry, providing use ful parallels with comparable metalloenzymes [6,7]. This work deals with the synthesis and character ization of Ni(II), Cu(II) and Fe(III) complexes of Schiff base which was prepared as recorded by H. Kara et al [9]. The coordination behavior of Schiff base towards transition metal ions is investigated via the FT IR, LC MS, magnetic moment and molar con ductance.…”

A New Tetranuclear Distorted Open-Cubane Copper(ii) Schiff Base Complex: Structural, Spectral and Magnetic Characterizations

“…Recently our research group and others have reported the structural and magnetic characterization of polynuclear copper(II) complexes with Schiff base ligands [15][16][17][18][19][20][21][22][23][24][25][26]. In view of the importance of copper(II) compounds and our interest in the magnetic properties of transition metal complexes, we report here the synthesis, crystal structure and magnetic properties of a new tetranuclear copper(II) complex containing three independent distorted open-cubane core.…”