dipicolinatecontaining

Dipicolinate-containing compounds are chemical species that incorporate the dipicolinate ligand, derived from dipicolinic acid (pyridine-2,6-dicarboxylic acid), as part of their coordination framework. In most cases the active binding unit is the dipicolinate dianion, which can bind metals through the pyridine nitrogen and two carboxylate groups.

Coordination modes are versatile. The dipicolinate ligand can act as a tridentate donor, coordinating to a single metal center, or as a bridging ligand linking multiple metal centers to form dinuclear complexes, coordination polymers, or extended metal-organic frameworks. Lanthanide dipicolinate complexes, such as Ln(DPA)3, exhibit well-defined photophysical properties; transition metal analogs also exist.

Synthesis typically involves deprotonation of dipicolinic acid to the dipicolinate dianion, followed by reaction with metal salts under solvothermal or hydrothermal conditions, often in polar solvents. Parameters such as pH, temperature, and auxiliary ligands influence nuclearity, topology, and framework formation.

Properties and applications include luminescence in lanthanide systems (antenna effect), magnetic materials, catalysis, sensing, and porosity in metal-organic frameworks for gas storage or separation. The class is of interest in solid-state chemistry and materials science, offering tunable structures and functions through choice of metal and auxiliary linkers.

Dipicolinic acid is also a biological marker in bacterial spores, where it contributes to spore stability, but dipicolinate-containing compounds are distinct chemical entities studied for coordination chemistry and materials science. See also dipicolinic acid, lanthanide coordination chemistry, and metal-organic frameworks.