SOF2, SOFCl, and SOCl2 were each paired with a series of N bases. The potential energy surface of the binary complexes were characterized by MP2 calculations with double and triple-xi basis sets, extrapolated to complete sets. The most stable configurations contained a S center dot center dot center dot N chalcogen bond with interaction energies as high as 6.8 kcal/mol. These structures are stabilized by a N-lp -> sigma*(SZ) electron transfer (Z = O, F, Cl), complemented by Coulombic attraction of N to the s-hole opposite the Z atom. N center dot center dot center dot SF and N center dot center dot center dot SCl chalcogen bonds are stronger than N center dot center dot center dot S-O interactions. Formation of each chalcogen bond elongates all of the internal covalent bonds within SOXY, especially the SCl bond. Halogen-bonded (N center dot center dot center dot ClS) complexes were also observed, but these are more weakly bound, by less than 3 kcal/mol.