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The interactions of water or methanol with nitromethane and dimethyl sulfone vs. comparison molecules, e.g. dimethylsulfoxide (DMSO), are reported. For nitromethane with water, the classical (edgewise) hydrogen bonded configuration is modestly stabilizing. However, the approach of water over the face of the nitro group is preferred in AM1 calculations. Generally, molecules such as sulfones and nitro compounds have lower energy bonding orbitals than sulfoxides. The energy of the n δ σ* interaction (e.g. nitro lone pair to O-H of water) thus is larger for the nitro and sulfone cases, and this interaction is less prevalent than other cases. Since the interaction of the nitro group with water is somewhat favorable, the reason for the insolubility of nitromethane is water was investigated. It was found that the energy of segregated sets of nitromethane and of water molecules was lower than the mixed nitromethane - water state. In contrast, the energy of the mixed DMSO-water hydrogen bonded mixed state is lower than segregated molecules.