Threading Salen-type Cu- and Ni-Complexes into One-Dimensional Coordination Polymers: Solution versus Solid State and the Size Effect of the Alkali Metal Ion

Compartmentalization of metal ions is crucial in biology as well as in materials science. For the synthesis of single source precursors, the preorganization of different metal ions is of particular interest for the low-temperature generation of mixed metal oxides. On the basis of a potentially Ω-shaped salen-type ligand providing an N₂O₂ as well as an O₂O₂ coordination site, mixed metal coordination compounds with Cu­(II) or Ni­(II) and alkali metal ions have been studied for their structural and optical properties. UV–vis and ¹H NMR titrations show that the obtained compounds adopt partially different structures in solution compared to the solid state. In the latter case, the coordination geometry is mainly governed by the size of the alkali metal ion as well as the transition metal ion used