Checking for the possibility of an 'amidomethyl' N-substituent being involved in the iminodiacetat-copper(II) chelation:: synthesis, molecular and crystal structure and properties of (imidazole)(N-carbamoylmethyliminodiacetat)copper(II), [Cu(ADA)(ImH)]

The stoichiometric reaction of copper(II) hydroxycarbonate, N-carbamoylmethyl-iminodiacetic acid [H(2)ADA = H2NCOCH2N(CH2CO2H)(2))], and imidazole (ImH) in water) yields crystalline samples of (imidazole) (N-carbamoylmethyl-iminodiacetate)copper(II), [Cu(ADA)(TmH)] (compound I). The compound was characterized by TG analysis (with IR study of the evolved gasses) and by spectral (IR, electronic and ESR spectral and single crystal X-ray diffraction methods. In compound I, ADA acts as a tetradentate ligand and the Cu(II) atom exhibiting a square base pyramidal coordination (type 4 + 1). Coordination bond distances (Angstrom): Cu(1)-N = 2,040(2), Cu(1)-O(11) = 1.943(2), Cu(1)-O(21) = 1.964(2) and Cu(1)-O(31) = 2.322(2) with ADA and Cu(1)-N(1) = 1.960(2) with ImH. The tetradentate chelating role of ADA is discussed on the basis of the preference to the O(amido) donor atom (versus the N one) of ADA to occupy an axial/remote coordination position around the Cu(II) atom as well as by the expected mer-chelating configuration of the 'Cu-iminodiacetato' moiety (Cu-IDA) upon the imidazole-copper(II) coordination in the studied mixed-ligand complex I (having a 1:1:1 Cu/ADA/ImH molar ratio). (C) 1999 Elsevier Science Ltd. All rights reserved.