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If you have any questions, please don't hesitate to contact me on my talk page. Ian (Wiki Ed) (talk) 19:03, 31 October 2018 (UTC)Reply


Peer review (Astatocarbon) edit

Overall, I thought the article was informative and covered the breadth of the literature cited on n-heterocylic silyenes. The article was detailed with respect to the major sections on synthesis, structure, and reactivity. Furthermore, the references cited cover the broad range of literature available on the topic. The figures were also generally helpful guides to the reader.

In terms of general improvements, the grammar and organization of the ideas in the main body of the text can be cleaned up: there are typos here and there. The references list at the end also have some sort of date value error. Specific suggestions and questions I had about each of the sections are described below.

Synthesis

  • When mentioning the NMR signals of your compounds, I’m curious to know if you’re referring to Si-NMR, H-NMR, or both.
  • When mentioning the reactivity of the compounds with silylene scavengers/Lewis bases, you mentioned triethylsilane as an example. However, the statement made is pretty general and I am wondering if other molecules were tested.

Structure and aromaticity

  • In the “Structure” section, I’m wondering if the literature believes the nitrogen forms a covalent or dative bond to the silicon center, since the nitrogens are as you mention Lewis basic. If there is discussion about it in the literature you read, perhaps one or two lines could be helpful for that frame of reference.
  • The “Aromaticity” section was written clearly, and I feel that I have a good sense of the methods used to probe differences between aromatic and non-aromatic species. The support from both experimental and theoretical work is good.
  • In the end of the section though, you compare the NMR resonance of the divalent Si with the reference cyclopentadienyl anion. The argument appears to be that the former is aromatic because it has a shift of -10.4 ppm compared to the -14.3 ppm shift of the latter: are these values supposed to be close? Based on the paper, it seems like they are arguing that a shift at that magnitude is aromatic. So it seems reasonable to explicitly state this comparison (by saying something along the lines of "the high magnitude of this shift, in reference to the aromatic Cp anion, indicates that it is aromatic").
  • In general, for the “Electronics” section, there are a few statements that were confusing to me or required some more clarification. For example, when referring to the papers from 1994 and 1996, it perhaps makes more sense to refer to the authors of the papers as well as the date if needed.
  • The ideas could also be reorganized to make it more clear that you are comparing the methodology and results of two particular studies, as well as what the point you are trying to make in that section is. For example, at the beginning of the paragraph, you can state that the energetics of the pi structure change between the saturated and unsatured pi structures based on authors X and authors Y.
  • Likewise, I think the pictures in the table could be broken up into multiple sets of images to help more clearly communicate the idea. Each can also be captioned as well. For example, if you are trying to show that the NHSilane HOMO does not have a p orbital, it would make sense to compare its HOMO to that of the other NHSi units. The same can be done with the LUMO and HOMO-1. The text in the table can also be confusing in absence of a deep reading of the main text.
  • The NBO analysis and AIM analysis sections are great though, and I understand from those sections the idea of how these techniques explain the nature of charge separation between bonds and the electron population in the relevant pi orbitals of interest. The AIM section can be reorganized to segment discussion of the NHSi to NHC electronic structure first, and then when the NHSi is coordinated to the metal. Right now, those ideas are mixed into each other and is confusing for the reader.

Main group reactivity

In general, this section had a lot of neat descriptions of the types of reactions that have been and can be accomplished with these compounds. The chalcogen reactivity in particular is an informative addition to the article, while the ideas presented in the transition metal coordination are clear. There are a few smaller points to make about some of the subsections:

  • Tetramerization: How did the authors come about this mechanism of tetramerization? You mention Raman spectroscopy was used to support the structure. Based on the information from the paper, it may be helpful a phrase to include a bit about how the insertion intermediate was captured with reaction from methanol, or that the authors used DFT to analyze the energetics of the reaction intermediates. As it is currently, it seems like the mechanism is fact and could benefit at least from saying that other methods were used to come to it.
  • Reactions with sigma bonds: The image for the reactions with sigma bonds could be a bit bigger.
  • Reactions with pi bonds: There are a lot of reactions going on in this section, and there is a lot to digest (especially with the amount of terminology). One possible way to improve this is to show a picture of the various products that can be made, rather than the reaction questions.

Transition metal complexes and reactivity

  • Other than a few typos, this reference is clear and covers the range of reactions and a bit about their methodlogy.

Overall, I think the article is good and serves as a comprehensive reference for those looking to learn more about it without having to directly access the literature.

--Astatocarbon (talk) 18:08, 1 December 2018 (UTC)Reply