Synthesis and Structure of Mononuclear Copper(II) Complexes with Azaheterocyclic Ligands L (L = Bipy, BPA, and Phen) and Dodecahydro-closo-Dodecaborate Anion [B12H12]2–

Abstract

A systematic study of copper(I)/copper(II) complexation with azaheterocyclic ligands and the boron cluster anions [B_nH_n]^2– (n = 10, 12) shows the possibility of synthesizing mononuclear, binuclear, trinuclear, tetranuclear, and polymeric copper(II) complexes. Here, we have studied copper(I) complexation with the [B₁₂H₁₂]^2– anion and azaheterocyclic ligands L (L = Bipy, BPA). The reaction have been carried out in air in organic solvents (CH₃CN and DMF). Under these conditions, copper(I) is oxidized, and mononuclear copper(II) complexes with ligands L and the [B₁₂H₁₂]^2– anion of different composition and structure are formed as final products. In addition, copper(II) complexes have been synthesized in the copper(I)/silver(I) system. The effects of the reaction conditions (the nature of the starting closo-dodecaborate, the source of copper(I), the presence of silver(I) compounds in the reaction solution) on the composition and structure of the final products have been shown. Reaction products have been identified by elemental analysis, IR spectroscopy, and X-ray diffraction. The structures of complexes [Ag(Bipy)₂]NO₃, [Cu(BPA)₂Cl]Cl · DMF, [Cu(BPA)₂Cl]₂ · 2DMF, [Cu(BPA)₂(DMF)₂][B₁₂H₁₂] · DMF, [Cu(BPA)₂][B₁₂H₁₂]]_n, and [Cu(Bipy)(DMF)₄][B₁₂H₁₂] have been determined by X-ray diffraction (CCDС nos. 1899332–1899337, respectively).