Hydrothermal synthesis of copper complexes of 4′-pyridyl terpyridine: From discrete monomer to zigzag chain polymer

Seven copper complexes Cu(L1)I₂] (1), Cu₂(L1)₂I₂]₂Cu₂(μ-I)₂I₂] (2), Cu(L2)I₂] (3), Cu₂(L2)(μ-I)I(PPh₃)] (4), Cu₄(L2)₂(μ-I)₂I₂] (5), {Cu(L2)I]₂Cu₂(μ-I)₂I₂]}_n (6) and Cu₂(L2)(μ-I)₂]_n (7) have been prepared by reactions of ligands: 4′-(2-pyridyl)-2,2′:6′,2″-terpyridine (L1) and 4′-(3-pyridyl)-2,2′:6′,2″-terpyridine (L2) with CuI in hydrothermal conditions, respectively. By alternating the oxidations states of the metal centers, increasing stoichiometric metal/ligand ratio and introducing a second ligand, the compounds, were successfully developed from mononuclear (1 and 3) to multinuclear (2, 4 and 5) and polymers (6 and 7). The synthesis of these compounds may provide an approach for the construction of coordination compounds of 4′-pyridyl terpyridine with different nuclearity.