The hydrogen bonding network in the dimer of syn-N-phenyl-N′-sulfinylhydrazine, PhNHNSO

N-phenyl-N′-sulfinylhydrazine (PhNHNSO) has been analyzed with infrared spectroscopic and computational methods. Experimental infrared spectra show a red shift of the frequency of the NH stretching vibration from monomer to dimer, confirming the presence of intermolecular NH⋯O hydrogen bonding interactions suggested from diffraction studies in the solid state. Computational investigations of the monomer confirm the preference of the syn configuration, as found in the dimer, over sickle and anti isomers. An analysis of the electron density within the framework of the quantum theory of Atoms in Molecules reveals the presence of intermolecular NH⋯O and CH⋯O interactions in the dimer, thus suggesting an alternate hydrogen bonding network from the one proposed from diffraction studies. The NH⋯O and CH⋯O interactions are identified as hydrogen bond and blue-shifting hydrogen bond, respectively.