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

The crystal and molecular structure of dinuclear complex [Cu2(DBM)2(μ-pz)(μ-OH)] (where: DBM – dibenzoylmethanate, pz – pyrazolate) was determined by X-ray diffraction method. Structure of [Cu2(DBM)2(μ-pz)(μ-OH)] consists of dinuclear unit in which the copper(II) ions are linked in the plane by N,N′-bridging pyrazolato and hydroxo anions. Terminal chelating dibenzoilomethanate anions are κ2 bound via oxygen atoms to each copper(II). The intradimer Cu(II)–Cu(II) distance and Cu(II)–O(OH)–Cu(II) angle are equal to 3.321(1) Å and 121.2(3)°, respectively. The dimers form stacks with short interdimer Cu(II)–Cu(II) contact of 3.535(1) Å. The variable-temperature magnetic susceptibility measurements (2–300 K) for a powdered sample of the complex were interpreted on the basis of the spin-hamiltonian yielding 2J=−217.8 cm−1, g=2.102, p=0.39%. The interdimer magnetic coupling was included to give antiferromagnetic coupling constant zJ′=−91.2 cm−1. The value of −2J observed in [Cu2(DBM)2(μ-pz)(μ-OH)] results from counterbalance between two different bridges in molecule.