Pyridine2carboxylic

Pyridine-2-carboxylic acid, commonly known as picolinic acid, is an aromatic carboxylic acid derived from pyridine with the carboxyl group substituting at the 2-position. Its molecular formula is C6H5NO2 and the molar mass is 123.11 g/mol. It typically appears as a white solid and is soluble in many organic solvents and in basic aqueous solutions.

Picolinic acid is a weak organic acid. The carboxyl group can lose a proton, and the acidity is influenced by solvent and temperature, with pKa values generally reported in the low-to-mid range (roughly 3.5 to 4.5 under common conditions). The pyridine nitrogen also affects the electronic properties of the molecule and its deprotonated form.

Coordination chemistry is a major area of interest for picolinic acid. It acts as a bidentate ligand, coordinating through the pyridine nitrogen and the carboxylate oxygen to form five-membered chelate rings with a variety of metal ions (for example Zn2+, Cu2+, Ni2+). These metal complexes are studied for catalysis, metal ion transport, magnetic and luminescent properties, and as model systems for ligand–metal interactions.

Applications and availability: picolinic acid is widely used as a building block in coordination chemistry and organic synthesis. Its metal complexes serve in analytical chemistry, materials science, and catalysis, and the compound is available commercially for research use.

Safety: picolinic acid can cause skin and eye irritation and may be harmful if ingested. Appropriate handling, including protective equipment and ventilation, is advised.