(Acetato-kappaO)aqua(1H-imidazole-kappaN3)(picolinato-kappa2N,O)copper(II) 0.87-hydrate: a Z' > 1 structure.

The crystal structure of the title compound, [Cu(C6H4NO2)(C2H3O2)(C3H4N2)(H2O)].0.87H2O, has a square-pyramidal-coordinated Cu(II) centre (the imidazole is trans to the picolinate N atom, the acetate is trans to the picolinate -CO2 group and the aqua ligand is in a Jahn-Teller-elongated apical position) and has two symmetry-independent molecules in the unit cell (Z' = 2), which are connected through complementary imidazole-picolinate N-H...O hydrogen bonding. The two partially occupied solvent water molecules are each disordered over two positions. The disordered solvent water molecules, together with pseudosymmetry elements, support the notion that a crystal structure with multiple identical chemical formula units in the structural asymmetric unit (Z' > 1) can represent a crystal 'on the way', that is, a kinetic intermediate form which has not yet reached its thermodynamic minimum. Neighbouring molecules form pi-pi stacks between their imidazole and picolinate N-heterocycles, with centroid-centroid distances in the range 3.582 (2)-3.764 (2) A.