5-n-butylpyridine-2-carboxylate-copper(II) and -iron(III) complexes

In trans-bis(5-n-butylpyridine-2-carboxylato-kappa(2) N,O)bis(methanol-kappaO)copper(II), [Cu(C10H12NO2)(2) (CH4O)(2)], the Cu atom lies on a centre of symmetry and has a distorted octahedral coordination. The Cu-O(methanol) bond length in the axial direction is 2.596 (3) Angstrom, which is much longer than the Cu-O(carboxylate) and Cu-N distances in the equatorial plane [1.952 (2) and 1.977 (2) Angstrom, respectively]. In mer-tris(5-n-butylpyridine-2-carboxylato-kappa(2) N,O)iron(III), [Fe(C10H12NO2)(3)], the Fe atom also has a distorted octahedral geometry, with Fe-O and Fe-N bond-length ranges of 1.949 (4)- 1.970 (4) and 2.116 (5)-2.161 (5) Angstrom, respectively. Both crystals are stabilized by stacking interactions of the 5-n-butylpyridine-2-carboxylate ligand, although hydrogen bonds also contribute to the stabilization of the copper(II) complex.