Microhydration of neutral and anionic nitromethane molecules was investigated up to \(n =10\) water molecules using dispersion-corrected density functional B2PLYPD with aug-cc-pVDZ basis sets. The calculated interaction energies of both anion and neutral nitromethane–water clusters were extrapolated to the complete basis set (CBS) limit. It was observed that the water molecules interact with the methyl group of the nitromethane in the case of a neutral molecule, whereas in anionic nitromethane hydration, water molecules build a hydrogen bond network strongly around the nitro group of the nitromethane. The SAPT analysis and MED critical point calculations have revealed that the anionic nitromethane–water cluster is more stable as compared to the neutral one. Further, the SAPT analysis showed that an increase in stability in case of the interaction in an anionic nitromethane–water complex is because of a higher attractive contribution from the electrostatic and dispersion components. The vertical detachment energy (VDE) and electron affinity (EA) values of nitromethane were also calculated, and the VDE values were found to be in good agreement with the experimental values.
Graphical abstract
Anionic Nitromethane-(H2O)n clusters investigated using Dispersion Corrected Density Functional Theory and compared with neutral counterparts. The calculated VDE values show good agreement with Experimental values.