Crystallographic and theoretical studies of 1-(1-naphthyl)-2-thiourea with intermolecular N-H...S heteroatom interaction and N-H...π interaction

A single crystal X-ray diffraction study of 1-(1-naphthyl)-2-thiourea (1) C11H10N2S indicates crystallization in the monoclinic space group C2/c, Z = 8, with unit cell parameters a = 15.3864(14) , b = 7.6090(7) , c = 17.0836(16) , beta = 91.7420(30)A degrees. In the crystal structure, two components of 1 are connected via intermolecular NH...S hydrogen bonds (the N...S distance of 3.371 ). In 1 there is an NH...pi interaction (with the N...pi distance of 3.804 and a possible N-H...pi distance of 3.196 ). The calculations of 1 at the B3LYP/cc-pVTZ, RHF/cc-pVTZ, RIMP2/cc-pVDZ, and RIMP2/cc-pVTZ levels of theory can almost reproduce the X-ray geometry. In addition, the binding energies of a dimer of 1 calculated by RIMP2 using the cc-pVDZ and cc-pVTZ corrected BSSE basis sets are -36.1 kJ/mol and -41.7 kJ/mol. The results suggest that complex 1 is significantly important for the attractive intermolecular interaction in 1.