On the S_N2 reactions modified in vibrational strong coupling experiments: reaction mechanisms and vibrational mode assignments

Abstract

Recent experiments have reported modified chemical reactivity under vibrational strong coupling (VSC) in microfluidic Fabry-Pérot cavities. In particular, the reaction rate of nucleophilic substitution reactions at silicon centers (SN2@Si) has...

Comment on “On the SN2 Reactions Modified in Vibrational Strong Coupling Experiments: Reaction Mechanisms and Vibrational Mode Assignments"

“…It would be naïve to consider the small split at the tail of the 1290 cm -1 cavity mode as strong coupling. In Figure 1B, the broad O-H stretching mode of methanol is centered at ~3350 cm -1 (not at ~3000 cm -1 as claimed 1 ), and the C-H stretch at 2952 cm -1 are also shown. As can be also be seen in Figure 1B, the 7 th and 8 th mode of the cavity are off-resonant from both the C-H and the O-H bands.…”

“…In the same way, the thermodynamics, in particular the entropy, can be highly affected by solvation and solvent dynamics. Not surprisingly, as can be seen in Table S4, 1 the entropy calculations are off by ca. 40 % since the computation assumes, as stated on page S2 line 3: "Gibbs free energies were obtained via the standard statistical mechanics ideal gas, rigid-rotor and harmonic oscillator models as standard conditions."…”

Making ab initio QED functional(s): Nonperturbative and photon-free effective frameworks for strong light–matter coupling

“…Many of the experimentally observed effects, in particular those involving chemical reactions under strong coupling, are so far theoretically not well understood ( 6 , 11 , 30 – 32 ). Detailed theoretical explanations are largely missing as strong light–matter coupling calls in principle for investigations within the framework of quantum electrodynamics (QED) ( 33 ).…”

Reply to the Comment on “On the SN2 Reactions Modified in Vibrational Strong Coupling Experiments: Reaction Mechanisms and Vibrational Mode Assignments”

“…We did not overlook this, and we here take the opportunity to explicitly show that the data reported in the supplementary material of reference 5 are actually fully consistent with our results and interpretation. Based on electronic structure calculations, in our original work 2 we assigned the character of the IR bands of the reactants that were subject to vibrational strong coupling experiments in references 4 and 5. For the case of the reaction reported in reference 5, the reactant's IR band at ~1100 cm -1 was assigned to a Si-O stretching band in the experimental paper.…”

“…5 In contrast, our calculations indicate that this band is due to a pure C-O stretching mode while the Si-O stretching vibration contributed to several modes in the 500-900 cm -1 region. 2 In Figure 1 (top), we show the experimental IR spectra of the reactant and products 1 and 2 (P CH and P OH , respectively) that were reported in the supplementary material of reference 5. The IR region centered at 1100 ± 20 cm -1 is highlighted in grey.…”