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

Abstract

We welcome the large number of theoretical studies to analyze our experiments on chemistry under VSC. As Climent and Feist state in their recent article, many details are not understood. 1 However, there should be no need to misrepresent our results. In their paper, the authors re-analyze, not the chemistry under VSC, but the reactions that we used that have been studied for over half a century and for which there is no consensus about the details of the mechanism. 2 Secondly, they try to assign the vibrational bands of the reactants. Indeed, as they find, they are often mixed (coupled vibrational modes). For simplicity, it is commonplace in chemistry to describe vibrations according to their main contribution, a convention that we follow in our papers. Since there are differences between our results and their calculations, they assume that our assignments are wrong. Finally, they conclude that we must have coupled the solvent, apparently by a higher cavity mode, despite the experimental proof to the contrary in the original paper.3 The proof that the solvent was not coupled is reproduced below for those who are interested, together with one example of an unequivocal assignment that was in the supplementary material, 4 which Climent and Feist presumably overlooked.

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

“…In conclusion, visualization of the normal modes of the three species and comparison with the experimental spectrum strongly suggests that the bands at ~1100 cm -1 in the reactant and product 1 and at ~1040 cm -1 in product 2 are due to the C-O stretching and not the Si-O stretching. In contrast to the claim raised in the comment that "Since there are differences between our results and their calculations, they assume that our assignments are wrong", 1 we again stress that our electronic structure calculations are consistent with the experimental results, and our paper does not imply or claim that any of these results are wrong. We simply used the combined information from experiment and calculations to obtain further insight and improve the assignments made initially.…”

“…In the comment on our work, the authors state that: "Since the Si-O cleavage reaction results in a product that no longer contains a Si-O bond, the absence of the 1110 cm -1 band in the IR spectrum of [product] 2 clearly shows that the 1110 cm -1 band is mainly associated with the Si-O stretch of product 1". 1 Although it is true that product 2 has no peak at 1100 cm -1 , the results reported in our original manuscript and its supplementary material indicate that this is because the C-O stretching band in this product is slightly red-shifted to the 1020-1060 cm -1 region (highlighted in yellow). 2 Such a shift is expected in product 2 since the functional group, which is an alcohol (C-O-H), is different to that of the reactant and product 1, which is a silyl ether (Si-O-C).…”

A perspective on ab initio modeling of polaritonic chemistry: The role of non-equilibrium effects and quantum collectivity

“…31 In addition, they provide a powerful approach to include dissipative processes by means of Lindblad terms or to extrapolate to large system sizes, far beyond any explicit computational description, in the dilute gas limit. 32 However, despite this impressive success, cases have been reported, where model predictions contradict experimental observations, 1,33 which has triggered controversial discussions between theoreticians and experimentalists. [33][34][35] Overall, there is a general consensus among the community that we still lack a detailed theoretical understanding of the relevant processes involved in polaritonic chemistry and considerable research effort is needed to unravel them.…”

“…32 However, despite this impressive success, cases have been reported, where model predictions contradict experimental observations, 1,33 which has triggered controversial discussions between theoreticians and experimentalists. [33][34][35] Overall, there is a general consensus among the community that we still lack a detailed theoretical understanding of the relevant processes involved in polaritonic chemistry and considerable research effort is needed to unravel them. Overcoming this theoretical shortcoming is of eminent importance for the maturity of the entire field.…”

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

“…In the comment on our work, the authors state that: "Since the Si-O cleavage reaction results in a product that no longer contains a Si-O bond, the absence of the 1110 cm -1 band in the IR spectrum of [product] 2 clearly shows that the 1110 cm -1 band is mainly associated with the Si-O stretch of product 1". 1 Although it is true that product 2 has no peak at 1100 cm -1 , the results reported in our original manuscript and its supplementary material indicate that this is because the C-O stretching band in this product is slightly red-shifted to the 1020-1060 cm -1 region (highlighted in yellow). 2 Such a shift is expected in product 2 since the functional group, which is an alcohol (C-O-H), is different to that of the reactant and product 1, which is a silyl ether (Si-O-C).…”