Synthesis, crystal structure, characterization, Hirshfeld surface, and DFT studies of a dimeric copper complex of 3-methylpyridine-2-carboxylic acid

A Cu(II) complex with 3-methylpyridine-2-carboxylic acid, formulated as (C14H12CuN2O4)n (Complex I), was synthesized and characterized using infrared spectroscopy (IR), thermogravimetric analysis (TGA) and single-crystal X-ray diffraction. The crystal structure of Complex I is monoclinic, space group P2₁/c, with unit-cell parameters a = 4.9892(6) Å, b = 15.002(2) Å, c = 8.5649(12) Å, and volume V = 638.49(15) Å3. The Cu(II) center adopts a quasioctahedral coordination geometry and is located at a crystallographic inversion center. Density functional theory (DFT) calculations and Hirshfeld surface analysis revealed that noncovalent interactions, including H···O, H···C, and π···π contacts, play a significant role in stabilizing the three-dimensional supramolecular architecture of the complex.