Structural characterization of C.I. Disperse Yellow 114

The X-ray single-crystal structure of the azo dye molecule, C.I. Disperse Yellow 114, with a 1-methyl-5-cyano-2-hydroxy-4-methyl-6-pyridone component, was studied. The dye crystallizes in the hydrazone form and hydrogen bonding and π–π stacking interactions play essential roles in the formation of a layer framework with a mean interlayer separation of 3.433(4) Å. Theoretical calculations compared the energy differences between single-crystal and energy-minimized structures as well as those between the pyridine-2,6-dione and the 2-hydroxy-6-pyridone isomer.