Crystal structure and spectroscopic properties of N′-methoxycarbonylsulfenyl-substituted ureas, CH3OC(O)SN(H)C(O)NRR′ [R = H, R′ = C(CH3)3 and R = R′ = CH2CH3]

Structural and spectroscopic properties of N,N-diethyl- (I) and N-tert-butyl-N′-methoxycarbonylsulfenyl urea (II) are analyzed using a combined approach with data obtained from X-ray diffraction, vibrational spectra and quantum chemical calculations. The molecular structures of CH3OC(O)SN(H)C(O)N(CH2CH3)2 (I) and CH3OC(O)SN(H)C(O)N(H)C(CH3)3 (II), the later co-crystallized with ethyl acetate (II 1/2EtOAc), were determined by X-ray diffraction methods. Compound I crystallizes in the triclinic space group P-1 and II·0.5EtOAc in the orthorhombic space group Pnma. In I, there are two independent but closely related molecules in the asymmetric unit whose conformations differ only in the orientation of the terminal N(CH2CH3)2 groups. Neighboring molecules in I exhibit NH⋯O interaction giving rise to a polymeric chains. The conformation of the OCOSNCON skeleton of II is almost identical to the corresponding one of both molecules of I. Neighboring molecules in II are linked through bifurcated NH⋯O⋯HN interactions giving rise to a polymeric chain. The vibrational properties have been studied by FTIR and FT-Raman spectroscopy along with quantum chemical calculations at the B3LYP/6-311+G* level.