Dimeric copper(II) complexes with an aminoalcohol and halogenobenzoic acids. The crystal and molecular structures of bis[2-Br-benzoato-μ-(2-diethylaminoethanolato-N,μ-O)copper(II)] and bis[3-Br-benzoato-μ-(2-diethylaminoethanolato-N,μ-O)copper(II)]