Mixed-ligand copper(II) complexes with N-methyl derivatives of iminodiacetato or imidazole: Crystal structures of (N-methyl-iminodiacetato)(imidazole) copper(II), [Cu(MIDA)(ImH)] and diaqua(iminodiacetato)(N-methyl-imidazole)copper(II) monohydrate, [Cu(IDA)(1MeImH)(H2O)(2)]center dot H2O

Equimolar (1:1:1) mixed-ligand Cu(II) complexes with iminodiacetato (IDA) or N-methyl-IDA (MIDA) and N-methyl-imidazole (1MeImH) or ImH, respectively, have been prepared and characterized by thermal, spectral, magnetic and X-ray diffraction methods. [Cu(MIDA) (ImH)] (I) crystallizes in the monoclinic system P2(1)/n (a = 12.465(3), b = 5.999(1), c = 14.733(3) Angstrom, beta = 111.91(1)degrees, Z=4, R = 0.043, R(w)= 0.047). The Cu(II) atom exhibits a flattened square base pyramidal coordination (type 4 + 1). The N and two O atoms of the tridentate MIDA and one N of ImH form the square base; one longer Cu-O bond with the next MIDA ligand in the chain complex completes the Cu(II) five-coordination. [Cu(IDA)(1MeImH)(H2O)(2)]. H2O (II) crystallizes in the orthorhombic system Pna2(1) (a = 14.733(2), b = 7.721(1), c = 11.288(1) Angstrom, Z=4, R = 0.041, R(w) = 0.043). The N and two O atoms from IDA and one N from 1MeImH define a square coordination; two longer Cu-OH, bonds complete the unsymmetrical elongated octahedral coordination of Cu(II) (type 4 + 1 + 1). The polar N-H bonds of ImH in I and of IDA in II as well as the O-H bonds of the water molecules of the latter compound are involved in hydrogen bonds. The stepwise water loss in II is explained on the basis of its structural role in the Cu(II) coordination and/or in the crystal packing.