Three microporous Zn coordination polymers constructed by 3,4,5-tris(carboxymethoxy)benzoic acid and 4,4′-bipyrdine: Structures, topologies, and luminescence

Abstract Three microporous Zn coordination polymers, [Zn 3 (OH) 2 (TCBA)(4,4′-bpy)]·5.5H 2 O ( 1 ), [Zn 3 (OH) 2 (TCBA)(4,4′-bpy) 1.5 ]·5H 2 O ( 2 ), and [Zn 4 (TCBA) 2 (4,4′-bpy) 2 (H 2 O) 8 ]·11H 2 O ( 3 ) (H 4 TCBA = 3,4,5-tris(carboxymethoxy)benzoic acid, 4,4′-bpy = 4,4′-bipyrdine), have been hydrothermally synthesized and structurally characterized. 1 presents an uncommon 2-nodal (4,10)-connected network with {3·4 5 } 2 {3 4 ·4 12 ·5 10 ·6 14 ·7 3 ·8 2 } topology; 2 can be described as a 2-nodal (3,8)-connected tfz-d net with the symbol of {4 3 } 2 {4 6 ·6 18 ·8 4 }, both networks are constructed from hexameric [Zn 6 (µ 3 -OH) 4 ] 8+ clusters. While 3 shows an interesting 4-nodal (3,3,3,4)-connected network with {8·10·12} 2 {8·10 2 } 2 {8 4 ·10·12} topology. Complexes 1–3 all own 3-D frameworks with 1-D channels, and in 1–3 lattice and/or coordinated water molecules occupy the channels, especially in 3 Zn-bipy chains reside in the channels together with water molecules. Double helical chains can be observed in complex 2 ; and single helix chains exist in complexes 1 and 3 . Furthermore, the thermal stabilities and photophysical properties of complexes 1–3 were also investigated.