Synthesis, Structures and Properties of Two New Coordination Polymers with Unprecedented Water Cluster

Abstract

Two new complexes, [Eu2(NIPH)2(H2O)14](HNIPH)2(H2O)7 (1) [Co2(abtc)(phen)4(H2O)]·12(H2O) (2) (H2NIPH = 5-nitroisophthalic acid, H4abtc = 3,3′,5,5′-azobenzenetetracarboxylic acid, phen = 1,10-phenanthroline, DMF = N,N′-dimethylformamide) have been synthesized and characterized by infrared spectrum, thermal gravimetric analysis, X-ray single crystal diffraction and photoluminescence properties. Complex 1 upon slow evaporation at room temperature gave a 0-D structure, and seven independent water molecules and their equivalent held together by hydrogen bonds with an ordered proton arrangement form a 1-D hydrogen-bonded water tape. An unusual water tape notated T10(0)A0 is observed in 2. A 1-D water tape by connecting five-ten-five membered water rings through hydrogen bonds. Multiple hydrogen bonds and π–π stacking interactions play important roles in the formation of the 3-D networks. Fascinatingly, these lattice water molecules display unprecedented water cluster and play important roles in the stabilizing the whole network.