Crystal structure, vibrational and NMR studies and chemical quantum calculations of 2-phenylazo-5-nitro-6-methyl-pyridine (C12H10N4O2)

Synthesis of 2-phenylazo-5-nitro-6-methyl-pyridine is described. Its X-ray structure is reported and discussed in terms of the molecular conformation of this compound. The crystal is triclinic, space group P-1, with the unit cell parameters a=6.372(1), b=7.522(2), c=12.495(2) Å, and α=6.372(1), β=89.62(3)° and γ=101.57(3)°. The pyridine and phenyl rings are planar deflected by torsional angle Ψ=4.8(3)°. The crystal structure is stabilised by non-classical hydrogen interaction of the C-H⋯O type with C⋯O distance 3.307(5) Å, H⋯O distance 2.481(3) Å and C-H⋯O angle equal to 147.8(3)°. These interactions in the crystal structure couple pairs of the molecules related by an inversion centre. FT-IR, Raman and NMR spectra of this compound have also been measured. The 6-31G(d,p) basis set with the B3LYP functional has been used to discuss the structure and dynamics of the compound studied.