Different water clusters dependent on long-chain dicarboxylates in two Ag(I) coordination polymers: Synthesis, structure and thermal stability

Two mixed-ligand Ag(I) coordination polymers (CPs), [Ag2(bipy)2(sub)·5H2O]n (1), [Ag2(bipy)2(aze)·3H2O]n (2), (bipy = 4,4′-bipyridine, H2sub = suberic acid, H2aze = azelaic acid) have been synthesized and structurally characterized by elemental analysis, infrared (IR) spectroscopy, powder X-ray diffraction (PXRD), thermogravimetric (TG) analysis, and single crystal X-ray diffraction. Both 1 and 2 are two-dimensional (2D) sheets based on infinite [Ag(bipy)]n double chain incorporating Ag⋯Ag interactions. Interestingly, two different water clusters are encapsulated in the voids between the sheets of 1 and 2. For 1, one water decamer (H2O)10 based on a cyclic water tetramer was hydrogen-bonded with the host 2D sheet. While, one water hexamer (H2O)6 also based on a cyclic water tetramer was observed in 2. Comparing the experimental results, it is comprehensible that the dicarboxylates play a crucial role in the formation of the different water clusters. Moreover, the thermal stabilities of them were also discussed.

► Two new mixed-ligand coordination polymers were synthesized and characterized.
► Two different water clusters were characterized by X-ray crystallography.
► Dicarboxylates play a crucial role in the formation of the different water clusters.