Crystallographic Analyses of High-Z Value Structure of a Pyridinium–Carboxylate Complex

Abstract

Equimolar amounts of the proton acceptor 2-aminopyridine 1 and proton donor picolinic acid 2 were solvent-free grinded to give complex 5. X-ray diffraction was used to determine the crystal structure of the new complex 5 that found to be ionic, with proton transfer occurring to the aromatic nitrogen of the 2-aminopyridine moiety. Nonclassical hydrogen bonding exist in the solid state structure of 5, such as, 2-aminopyridine-carboxylic acid supramolecular heterosynthon was carefully investigated and compared to those exist in cocrystals in terms of supramolecular chemistry and crystal engineering. Complex 5 crystallizes in the monoclinic P2(1)/n space group with unit cell parameters of: a = 8.7714(12) A, b = 12.1579(17) A, c = 10.8546(15) A, with α = 90°, β = 110.100(4)°, γ = 90°, and Z = 4. Equimolar amounts of the proton acceptor 2-aminopyridine 1 and proton donor picolinic acid 2 were solvent-free grinded to give complex 5. X-ray diffraction was used to determine the crystal structure of the new complex 5 that found to be ionic, with proton transfer occurring to the aromatic nitrogen of the 2-aminopyridine moiety. Nonclassical hydrogen bonding exist in the solid state structure of 5, such as, 2-aminopyridine-carboxylic acid supramolecular heterosynthon was carefully investigated and compared to those exist in cocrystals in terms of supramolecular chemistry and crystal engineering.