The crystal structure of 5-(tri­fluoro­meth­yl)picolinic acid monohydrate reveals a water-bridged hydrogen-bonding network

The title compound [systematic name: 5-(tri­fluoro­meth­yl)pyridine-2-carb­oxy­lic acid monohydrate], C(7)H(4)F(3)NO(2)·H(2)O, is the acid hydrate of a pyridine with a carb­oxy­lic acid group and a tri­fluoro­methyl substituent situated para to one another on the aromatic ring. The mol­ecule forms a centrosymmetric water-bridged hydrogen-bonding dimer with graph-set notation R (4) (4) (12). Hydrogen-bonding distances of 2.5219 (11) and 2.8213 (11) Å are observed between the donor carb­oxy­lic acid and the bridging water acceptor, and the donor water and carbonyl oxygen acceptor, respectively. The dimers are further linked into a two-dimensional sheet via two longer inter­molecular hydrogen-bonding inter­actions between the second hydrogen atom on the bridging water mol­ecule and both a pyridine nitro­gen atom and carbonyl oxygen with distances of 3.1769 (11) and 2.8455 (11) Å, respectively. The tri­fluoro­methyl groups extend out the faces of the sheet providing for F⋯F and C—H⋯F contacts between the sheets, completing the three-dimensional packing.