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

The coordination polymer {[Zn 2 (1,3-pda) 2 (bpp) 2 ]·5H 2 O} n ( 1 ) (1,3-H 2 pda = 1,3-phenylene-diacrylic acid, bpp = 1,3-bis(4-pyridyl)-propane) was obtained from the hydrothermal reaction of Zn(NO 3 ) 2 ·6H 2 O, 1,3-H 2 pda, 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 (H 2 O) 5 water cluster. Thermal and luminescent properties of 1 were also investigated.