Near-Infrared Absorbing Molecule Based on Triphenylamine Radical Cation with Extended Homoaryl π-System
Round 1
Reviewer 1 Report
The authors describe an article entitled “Near-infrared absorbing molecule based on triphenylamine- radical cation with extended homoaromatic π-system”. The topic of the manuscript is interesting, and the manuscript constitutes an interesting research article concerning the development of NIR dyes.
The work is well-written and a well-constructed introduction has been established by the authors. Sufficient spectra and figures are included in the manuscript for comprehension and clarity. Interesting and convincing results are also presented in this work. Overall, I think that this is a manuscript that I recommend for publication after inclusion of minor revisions.
1) What is the stability of NIR dyes over time ?
2) For all compounds, HMRS should be added in SI.
3) EPR experiments have not been carried out after oxidation. It should be added
Author Response
Comments from Reviewer 1
What is the stability of NIR dyes over time ?
Thank you for pointing this out. As shown in Figure 9 (main text), and Figure S22-S24 (SI), These NIR dyes (radical cationic species) did not degrade at all at room temperature in solution. We have also shown that compounds 4 could be quantitatively recovered in solution by chemical oxidation to radical cations, followed by reduction with ascorbic acid (Figure S29-S30). Attempts to isolate these radical cationic species as crystals are also of interest, we are currently making efforts to isolate them. If a crystal structure is obtained, we will publish it in the future.
For all compounds, HMRS should be added in SI.
Thank you for pointing this out. HRMS of compounds 2-5 was performed and satisfactory results were obtained. These results were added to SI.
EPR experiments have not been carried out after oxidation. It should be added.
Thank you for this suggestion. The EPR spectra of the radical cation obtained by chemical oxidation of compound 2-5 was measured and confirmed the presence of open-shell species. These results were added to SI (Figure S39-S42).
Reviewer 2 Report
Comments for author File: 
Comments.pdf
Author Response
Comments from Reviewer 2
Page No, 1, Line 24, "ormetal" may be read as "or metal"
Thank you for these suggestions. We have corrected the issues pointed out by the reviewer 2. Thank you for your detailed reading.
The references listed need to be consistent in their style and format.
Thank you for pointing this out. The bibliography section has been modified according to the bibliography format specified for this journal. Links to the respective references (doi) have been removed.
Reviewer 3 Report
I attached the report for the authors to make the suggested corrections.
Comments for author File: Comments.pdf
Author Response
Comments from Reviewer 3
I read this work very carefully and found that the manuscript is not written very carefully. The first question I would like to ask the authors is why they say in the abstract that "Molecular design rules of novel near-infrared absorbing dyes are described" but then in the experimental part of the supplementary material, in particular in the description of the NMR spectra, they say that the spectra are in accordance with those referred to in the literature and they present the respective bibliographic reference.
Reply: Thanks for pointing this out. I have added details on (i) how promising the four molecules in this study are as near-infrared absorbing materials and (ii) all of them are known compounds but have not been studied as near-infrared absorbing materials (Line 100 to 106).
Line 13 – Unless they are very common, abbreviations should not appear in the abstract, so it is suggested that the authors replace the abbreviation "CV" by cyclic voltammetry (CV).
Line 24 – change ..."ormetal".. to ..."or metal"...
Line 28 – change .. "squalium dyes"....to .."squarylium dyes"
Line 90 change .." See SI for more information on the results of DFT calculations. These results suggest"...to..." These results (see SI for more information on the results of DFT calculations.) suggest...."
Line 117 – change ..."solvents. See SI for details for solubilities of 2-5 in various organic solvents." ..to " ...solvents (see SI for details for solubilities of 2-5 in various organic solvents.)"
Line 123 – change ..."In this study, We have prepared..." to " In this study, we have prepared..." Line 149 .."Table 1." change to "Table 1."
Line 194 -149 .."Table 3." change to "Table 3."
Line 203 – Change "..almost completely" to ".. almost completely."
In the SI:
1-"A mixture of 4, 4', 4''-tribromotriphenylamine (521 mg, 1.05 mmol), pheylboronic" change to "A mixture of 4, 4', 4''-tribromotriphenylamine (521 mg, 1.05 mmol), phenylboronic" 2-Tri([1,1':4',1''-terphenyl]-4-yl)amine. (3). Change to Tri([1,1':4',1''-terphenyl]-4-yl)amine (3).
3- In the synthesis of compounds 3 and 5, the authors refer to that used of potassium tert-butoxide but under the arrows there is K2CO3.
4- in the synthesis of compoun5 change 132.26,. to "132.26,"
5- The authors have to put the name of "Radical cation of ..... (2•+)"
6- ...Change "ml" to "mL"
7 – Caption Figure S27 change "fluorescence fluorescence spectrum." to "fluorescence spectrum."
8- Missing to put the pages of reference 1.
Reply: These are the suggested typographical and stylistic corrections noted by the reviewer 3.
All the sections pointed by the reviewer 3 have been corrected. Thank you for your detailed reading.
