Assembly of discrete linear (H2O)5 water cluster within an entangled two-dimensional coordination network

The coordination polymer {[Zn2(1,3-pda)2(bpp)2]·5H2O}n (1) (1,3-H2pda = 1,3-phenylene-diacrylic acid, bpp = 1,3-bis(4-pyridyl)-propane) was obtained from the hydrothermal reaction of Zn(NO3)2·6H2O, 1,3-H2pda, bpp in a 1:1:1 molar ratio in the presence of NaOH. Single-crystal X-ray diffraction analysis reveals that 1 is a two-fold interpenetrating two-dimensional network containing small cavities. Within each cavity of the entangled network, five water molecules are aggregated to form an unique discrete linear (H2O)5 water cluster. Thermal and luminescent properties of 1 were also investigated.