Zwitterionic and neutral binuclear complexes formed from copper(II) hexafluoroacetylacetonate and an amino alcohol

Reaction of anhydrous Cu(hfac)₂ (hfacH = 1,1,1,5,5,5-hexafluoro-2,4-pentanedione) with 2-(diisopropylamino)ethanol yields two different binuclear copper(II) complexes. Compound 1, [Cu(hfac)₂(-OCH₂CH₂NH(i-Pr)₂)]₂, Cu₂C₃₆H₄₂O₁₀N₂F₂₄, consists of centrosymmetric dimers containing two cis-Cu(hfac)₂ moieties that are bridged by two zwitterionic 2-(diisopropylammonio)ethoxide ions. Cell parameters are a = 11.6516(13); b = 14.0117(17); c = 15.3258(17) Å = 105.75(9)° in space group P2₁/n. The copper ions exhibit tetragonally distorted octahedral coordination, with two of the Cu—O(hfac) distances showing characteristic elongation (2.2858(16) and 2.3192(17) Å). Compound 2, [Cu(hfac)((i-Pr)₂NCH₂CH₂O)]₂, Cu₂C₂₆H₃₈O₆N₂F₁₂, also contains centrosymmetric dimers; these are formed by two square-pyramidal moieties joined at their bases. Cell parameters are a = 7.7353(5); b = 13.6166(17); c = 15.683(2) Å = 98.23(1)° in space group P2₁/n. In this structure the apical Cu—O(hfac) distance is elongated (2.254(4) Å), and the O atoms of the 2-(diisopropylamino)ethoxide ions are bridging.