Content of review 1, reviewed on October 23, 2023

Given the difference in electronic structure between both systems, I concur with the study's conclusions regarding the limitation of using highly charged models and transferring the results to a system stabilized by ligands. This work aptly critiques the previous analysis by Lin and Mo. However, I also align with reviewer #3's criticism when considering that another methodology refers to a different criterion for aromaticity, such as the magnetic one. Tomeček, Liddle and Kaltsoyannis's work suggests diatropicity, implying aromaticity. There are instances where a discrepancy exists between bond analysis, electron count (4n+2), and magnetic properties concerning a system's aromaticity assignment. Take, for example, Re3(μ-Cl)3Cl6. Bond analysis (AdNDP) predicts it is non-aromatic with three localized 2c-2e Re=Re pi bonds (Inorganic Chemistry, 31:1-2, 2-12, DOI: 10.1080/02603590903498639). However, a detailed analysis of magnetically induced current density foretells the Re3 ring, showing an intense diatropic ring current, signifying aromaticity by IUPAC standards. It is crucial to understand that different aromaticity criteria coincide in organic systems. However, discrepancies among these criteria can emerge when applied to other systems, like the octet rule, as with several other chemistry rules.
Given the above, I support this manuscript's valid critique of Lin and Mo's prior work. Still, it is essential to highlight that aromaticity in these systems remains an open discussion.

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    © 2023 the Reviewer.

Content of review 2, reviewed on October 29, 2023

I have reviewed this new version of the manuscript and find that the author has not considered my comments from the previous review. Therefore, I will be more specific: in my view, this work offers an improvement over the previous BLW-DFT analysis by Lin and Mo. However, the analysis has intrinsic limitations, and it's impossible to assert definitively that this lack of extra cyclic resonance energy is conclusive. The most evident limitation is using reference systems, where it's impossible to ensure that the energy due to cyclic electron delocalization is accurately separated. Even in the most classic case, like cyclopropane C3H6, I doubt that the localization scheme accurately accounts for the cyclic delocalization energy in this system, hence its contrast with a ring current indicating aromaticity. The advantage of ring currents is that they do not depend on reference systems if they are evaluated with the appropriate level of theory.
Therefore, I believe even the title "The Curious Case of the Crystalline Tri-Thorium Cluster: Cyclic Delocalization Without Aromatic Stabilization" is imprecise. This part is correct if "cyclic delocalization" refers to the diatropic ring current in an external magnetic field. However, the non-existence of aromatic stabilization energy is only pointed out by the BLW-DFT method. Therefore, I maintain my critique. This work provides a better BLW-DFT analysis of these systems compared to previous works, but it doesn't paint a definitive picture of the aromaticity of these systems.

Expanding the discussion to highlight the challenges when analyzing the aromaticity in such systems would be advisable because even the methodologies might fall short. As I mentioned, a classic case is a cyclopropane (the references for which are well-known). Perhaps a more specific case (among many others) is that of Cl9Re3, where the current density analysis indicates that the system is aromatic (J. Phys. Chem. Lett. 2015, 6, 21, 4326–4330), contrasting with other studies based on electronic delocalization (THE CHEMICAL BONDING OF Re3Cl9 AND REVEALED BY THE ADAPTIVE NATURAL DENSITY PARTITIONING ANALYSES, Comments on Inorganic Chemistry, 31:1-2, 2-12, DOI: 10.1080/02603590903498639).
The aromaticity concept becomes intricate and complex as we move away from benzene. A valuable contribution to this field would be clearly defining the potential limitations of the analysis methods, given the complexity of the systems under study.

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    © 2023 the Reviewer.

Content of review 3, reviewed on November 15, 2023

I appreciate the author's response to my inquiries regarding the presence of ring current in this system. The inclusion of Cina's findings, which convincingly argue the absence of ring current in this context, is highly valuable. Further, the debate about the connection between ring current and aromaticity, particularly with using 18-annulene as a model, is intriguing. Although this compound has a ring current strength of around 5nA/T, suggestive of moderate aromaticity compared to benzene’s 12nA/T, the assessment does not fully account for the relationship between current intensity and ring size, as described by the Biot-Savart law. When normalized by the number of atoms, the comparison becomes 0.3 nA/T for 18-annulene versus 2nA/T for benzene, indicating that 18-annulene has only 15% of the normalized current strength relative to benzene. Overall, I am pleased with the author's response and recommend publishing this work in RSCadv.

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    © 2023 the Reviewer.

References

    W., S. D. 2023. The curious case of the crystalline tri-thorium cluster: cyclic delocalization without aromatic stabilization?. RSC Advances.