Ethylendiamin-kupfer(II)-komplexe mit polyolat-ionen aus rac-trans-cyclohexan-1,2-diol, erythritol und methyl-α- d-mannopyranosid. Herstellung und kristallstrukturen von [(ethylendiamin)Cu(C 6H 10O 2)] · H 2O, [(μ-ethylendiamin){Cu 2(ethylendiamin) 2(μ′- meso-butantetraolat(4 −))}] · 8H 2O und [(ethylendiamin)Cu(α- d-man pOMeH [2,3]2−2)] · 2H 2O

Abstract

The ethylenediamine-copper-polyolate complexes [(ethylenediamine)Cu(C 6H 10O 2)]·H 2O ( 1), [(μ-ethylenediamine){Cu 2(ethylenediamine) 2(μ′- meso-butanetetraolate(4 − ))}]·8H 2O ( 2), and [(ethylenediamine)Cu-(methyl α- d-mannopyranosid-2,3-ate(2 −))]·2H 2O ( 3), were formed as violet to blue crystals by the reaction of aqueous ethylenediamine, cupric hydroxide, and the polyol rac-trans-cyclohexane-1,2-diol, erythritol, or methyl α- d-mannopyranoside, respectively. The structures of the coordination compounds have been determined by X-ray crystallography. The number of deprotonated OH groups of the polyols is equal to the stoichiometric amount of OH − ions present in the solution. The respective deprotonated polyols bind as chelate ligands to copper(II) ions. In all three structures, the deprotonated hydroxyl groups are acceptors of asymmetric hydrogen bonds. In 1 and 3, the coordination geometry of copper is square planar (CuO ≈ 193, CuN ≈ 200 pm) with additional aqua ligands at a longer distance (> 280 pm). The square pyramidal complex 2 (193, 204, and 240 pm for CuO, CuN e, and CuN a, respectively) crystallizes from solutions with excess ethylenediamine; the compound is a polymer due to bridging ethylenediamine and erythritol ligands. The structures of the new compounds are discussed in context to cellulose copper complexes in the cellulose solvents Cuoxam and Cuen.