The first coordination compound of 6-fluoro-nicotinate: the crystal structure of a one-dimensional nickel(II) coordination polymer containing the mixed ligands 6-fluoro-nicotinate and 4,4'-bi-pyridine.

A one-dimensional nickel(II) coordination polymer with the mixed ligands 6-fluoro-nicotinate (6-Fnic) and 4,4'-bi-pyridine (4,4'-bpy), namely, catena-poly[[di-aqua-bis-(6-fluoro-pyridine-3-carboxyl-ato-κO)nickel(II)]-µ-4,4'-bi-pyri-dine-κ2 N:N'] trihydrate], {[Ni(6-Fnic)2(4,4'-bpy)(H2O)2]·3H2O} n , (1), was prepared by the reaction of nickel(II) sulfate hepta-hydrate, 6-fluoro-nicotinic acid (C6H4FNO2) and 4,4'-bi-pyridine (C10H8N2) in a mixture of water and ethanol. The nickel(II) ion in 1 is octa-hedrally coordinated by the O atoms of two water mol-ecules, two O atoms from O-monodentate 6-fluoro-nicotinate ligands and two N atoms from bridging 4,4'-bi-pyridine ligands, forming a trans isomer. The bridging 4,4'-bi-pyridine ligands connect symmetry-related nickel(II) ions into infinite one-dimensional polymeric chains running in the [10] direction. In the extended structure of 1, the polymeric chains and lattice water mol-ecules are connected into a three-dimensional hydrogen-bonded network via strong O-H⋯O and O-H⋯N hydrogen bonds, leading to the formation of distinct hydrogen-bond ring motifs: octa-meric R 8 8(24) and hexa-meric R 8 6(16) loops.