Ab initio prediction of the structure and energetics of the complexes of 4-nitrophenyl[bis(methylsulfonyl)]methane and TBD base in vacuo and acetonitrile solvent

The structure and energetics of the complexes of 4-nitrophenyl[bis(methylsulfonyl)]methane (I) with 1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD) in vacuo and in acetonitrile solvent are predicted at the MP2/cc-pVDZ level of theory. In the gas phase, the energies of possible ion-pair complexes are calculated to be −92.0 (structure 1), −100.4 (structure 2), −100.7 (structure 3), and −75.3 kcal mol−1 (structure 4), relative to the energy of the separated ions. In acetonitrile solvent, the corresponding relative energies are −109.6, −116.0, −114.8, and −105.7 kcal mol−1. The NH-ON complex seems to be unfavorable energetically in the solid state, however, it becomes more possible in acetonitrile, as indicated by the reduced relative energy values.