Structural effects and hydrogen bonds on N,N′-di(methoxycarbonylsulfenyl)urea, [CH3OC(O)SNH]2CO, studied by experimental and theoretical methods

Pure N,N′-di(methoxycarbonylsulfenyl)urea, [CH3OC(O)SNH]2CO, is quantitatively prepared by the hydrolysis reaction of CH3OC(O)SNCO and characterized by 1H NMR, GC–MS and FTIR spectroscopy techniques. Structural and conformational properties are analyzed using a combined approach with data obtained from X-ray diffraction, vibrational spectra and theoretical calculation methods. The IR and Raman spectra for normal and deuterated species are reported. The crystal structure of [CH3OC(O)SNH]2CO was determined by X-ray diffraction methods. The substance crystallizes in the orthorhombic P21212 space group with a = 9.524(2), b = 12.003(1), c = 4.481(1) Å, and Z = 2 moieties in the unit cell. The molecule is sited on a twofold crystallographic axis (C2) parallel to c and shows the anti–anti conformation (S–N single bonds antiperiplanar with respect to the opposite C–N single bonds in sulfenyl-ureasic group). Neighboring molecules are arranged in a chain motif that extends along the C2-axis and is held by bifurcated NH⋯O⋯HN intermolecular bonds. A local planar symmetry is observed in the crystal for the central –SN(H)C(O)N(H)S– skeleton. Experimental and calculated data allow to trace this structural feature to the occurrence of N–H⋯OC hydrogen bonding interactions. Calculated vibrational and structural properties are in good agreement with the experimentally determined features.