Fig. 3. Intermolecular interactions observed during AIMD simulations. (a) Benzene–SO₃ interactions in gas phase. Superposition of snapshots of the benzene···SO₃···SO₃ complex in top view (left) and side view (right). Dots represent the S atom positions of the primary SO₃ (red) and assisting SO₃ (blue). (b) Specific SO₃–CH₃NO₂ interactions. Probability isosurface (red) of CH₃NO₂ O atoms around the SO₃ S atom in a benzene···SO₃ complex (left) and in separated SO₃ (right). (c) Specific benzene–CH₃NO₂ interactions. Probability isosurface of solvent O (red) and C (grey) atoms around benzene C atoms, in a benzene···SO₃ complex (left) and in separated benzene (right). Deviations from symmetry in the isosurfaces are due to finite sampling.