The hydrazo-bond in 4,4′-dimethyl-3,3′-dinitro-2,2′-hydrazobipyridine – Crystal structure, conformation and vibrational characteristics

Abstract

The crystal and molecular structure of 4,4′-dimethyl-3,3′-dinitro-2,2′-hydrazobipyridine have been determined by X-ray diffraction and quantum chemical DFT analysis. The title compound crystallizes in P1¯ space group, with one-half molecule in the asymmetric unit. The molecular structure is stabilized by intramolecular NH···O hydrogen bonds. The molecules are linked by a combination of weak intermolecular CH⋯O interactions and also aromatic π–π stacking. The molecular structure of the studied compound has been determined using the DFT B3LYP/6-311G(2d,2p) approach and compared to that derived from X-ray studies. The IR and Raman wavenumbers have been calculated for the optimized geometry of a possible monomer structural model. The structural and vibrational properties of the intramolecular NH···O interaction are described.