One-pot synthesis of two new metal–organic networks: hydrogen bonded mononuclear Cu(II) complex and mixed-valence Cu(I,II) coordination polymer with encapsulated 14-membered unique water cluster

•A unique 14-membered water cluster motif•A new mixed-valence Cu(I,II) coordination polymer•Two new copper complexes were formed in the same reaction medium.

{[Cu4(μ-bpe)4Cu2(μ-pydc)2(μ3-pydc)2]·14H2O}n (1) and [Cu(pydcH)2(bpe)2] (2) have been solvothermally synthesized by 1,2-bis(4-pyridyl)ethylene (bpe) along with dianionic pyridine-2,3-dicarboxylate (pydc) ligands and characterized by elemental, FT-IR and thermal analyses techniques. In the solvothermal synthesis of complexes, 1 was isolated when the reactor was opened whereas 2 was crystallized after 3 weeks. The X-ray crystallographic studies show that complex 1 exhibits ladder-like structure involving mixed-valence Cu(I,II) which has generated a simultaneous in situ redox reaction and a unique 14-membered water cluster consisting of an eight-membered open-cube hexamer and two cyclic water trimers has been observed in hydrophilic cavities of 1. Supramolecular network of 2, which has proton transfer product of pydcH cations, is formed by O–H···N and aromatic interactions.

Graphical abstractTwo new copper organic networks are solvothermally synthesized in one pot. In 1, 1D ladder-like structure consists of mixed valence Cu(I, II), which is obtained by an in situ redox reaction and it has a unique 14-membered water cluster. Complex 2 has proton transfer product and it is formed by O–H···N and aromatic interactions.Figure optionsDownload full-size imageDownload as PowerPoint slide