New binuclear copper(II) complexes [Cu2(L)4(μ-CO3)][B12H12] (L = bipy, phen): Synthesis, structure, and magnetic properties

Abstract

The processes taking place in the Cu^I/L/solv system (L = bipy, phen) in the presence of the [B₁₂H₁₂]^2– anion, which exhibited the lowest reducing ability among the [B_nH_n]^2– cluster anions (n = 6, 10, 12), were studied. The binuclear complexes [Cu₂(L)₄(μ-CO₃)][B₁₂H₁₂] · n(solv) were found to be formed upon the redox reaction of (C₆H₅)₄P[Cu[B₁₂H₁₂]] with a twofold excess of L or the reaction of copper(II) complex [(Cu₂(phen)₄(CO₃)]Cl₂ with [(C₄H₉)₃NH]₂[B₁₂H₁₂]. The Cu(II) complexes were characterized by X-ray diffraction; their EPR-spectra were studied at 295 K and the magnetic measurements were performed in the 300–2 K range. In the [Cu₂(phen)₄(μ-CO₃)][B₁₂H₁₂] · DMF dimer with the anti-anti coordination of the (μ-CO₃)-group, strong antiferromagnetic interactions occur between the Cu(II) atoms (Cu⋯Cu = 5.107 Å).