Lamellar Tetragonal Symmetry of Amphiphilic Thermotropic Ionic Liquid Crystals in the Framework of Other Closely Related Highly Ordered Structures

Round 1

Reviewer 1 Report

Manuscript ID: symmetry-1581419

 

Title: Lamellar Tetragonal Symmetry of Amphiphilic Thermotropic  Ionic Liquid Crystals in the Framework of Other Closely Related Highly Ordered Organizations

 

 

Reviewer’s comments:

 

 

1. In the title, it is just a suggestion, but probably “highly Ordered Structures” sounds better.
2. In the Abstract, r.16 and r.164: X-ray
3. Introduction, in the revised manuscript, to enrich the domain of the research background, the authors are invited to read and add as reference the paper:  

 

 Ganea, C.P., Cîrcu, V. and Manaila-Maximean, D., 2020. Effect of titanium oxide nanoparticles on the dielectric properties and ionic conductivity of a new smectic bis-imidazolium salt with dodecyl sulfate anion and cyanobiphenyl mesogenic groups. Journal of Molecular Liquids, 317, p.113939. DOI: 10.1016/j.molliq.2020.113939

 

1. Section 2, especially rows 213-243: the information presented in this section is difficult to follow. Could you organize it better? Could you find a way to add also some Tables containing in an organized way the information in Section 2?

The paper can be published after the authors have addressed the above mentioned issues.

Major revision.

Author Response

1. In the title, it is just a suggestion, but probably “highly Ordered Structures” sounds better.

 

Suggestion Accepted

 

1. In the Abstract, r.16 and r.164: X-ray

 

It is corrected. We thank the reviewer for pointing this out.

 

1. Introduction, in the revised manuscript, to enrich the domain of the research background, the authors are invited to read and add as reference the paper:  

 

 Ganea, C.P., Cîrcu, V. and Manaila-Maximean, D., 2020. Effect of titanium oxide nanoparticles on the dielectric properties and ionic conductivity of a new smectic bis-imidazolium salt with dodecyl sulfate anion and cyanobiphenyl mesogenic groups. Journal of Molecular Liquids, 317, p.113939. DOI: 10.1016/j.molliq.2020.113939

Reference was incorporated into the introduction

1. Section 2, especially rows 213-243: the information presented in this section is difficult to follow. Could you organize it better? Could you find a way to add also some Tables containing in an organized way the information in Section 2?

 

The part between rows 213-243 was revised. A comparison of the discussed geometrical parameters of the two categories of quaternary ammonium salts is presented in the six parts of Figure 7 to help the reader follow the information.  

Reviewer 2 Report

This is a well-documented review on a quite specialized field of liquid crystal research. The topic on tetragonal symmetry fits the scope of the journal. The general introduction is suited for non-specialized readership and the argumentation is well supported by chosen references. However, the conclusion-discussion part needs major revisions. The manuscript will certainly deserve publication after consideration of following points.

1. As a secondary remark, authors should respect the indications of IUcr and International Tables for the notation for space groups: first letter in capital-italics, numbers in plain, other letters in italics. Therefore, space group notations in lines 110, 233 and 340 should be corrected, please. Similarly, conventions of IUcr is to note lattice parameters in italics, which should be applied to "a", "b", "c" in lines 343-344, for instance.
2. More importantly, the following statement in conclusion is wrong: "In the cases of similar ion volumes, the hexagonal configuration is thermodynamically favored". Providing that similar ion volumes means similar cross-sectional area within smectic layers, then the tetragonal configuration should be thermodynamically favored, due to the mechanism discussed by authors in lines 517-522. Conversely, this mechanism and the tetragonal configuration should be hampered when cations and anions have very different cross-sections.
3. The point upon the different role anion and cation size in lines 531-534 should be discussed and documented. The main difference is probably that the cation bear chain substituents having a volume, while the anions have no substituents.
4. What are (i) and (ii) in lines 525 and 534 for?
5. Point in lines 534-535 needs reference.
6. Point in lines 535-537 is merely related to cross-section discrepancy between chains and ions. This is hardly in the scope of the paper and could either be suppressed or on the contrary maintained with additional explanations.
7. Statement in lines 538-540 must be supported with literature references or removed.

Author Response

1. As a secondary remark, authors should respect the indications of IUcr and International Tables for the notation for space groups: first letter in capital-italics, numbers in plain, other letters in italics. Therefore, space group notations in lines 110, 233 and 340 should be corrected, please. Similarly, conventions of IUcr is to note lattice parameters in italics, which should be applied to "a", "b", "c" in lines 343-344, for instance.

 

Corrections have been made. We thank the reviewer for pointing out these errors.

 

1. More importantly, the following statement in conclusion is wrong: "In the cases of similar ion volumes, the hexagonal configuration is thermodynamically favored". Providing that similar ion volumes means similar cross-sectional area within smectic layers, then the tetragonal configuration should be thermodynamically favored, due to the mechanism discussed by authors in lines 517-522. Conversely, this mechanism and the tetragonal configuration should be hampered when cations and anions have very different cross-sections.

 

This is a very interesting point meriting a long discussion and scientific debate and could perhaps even be the subject of another review when more research will produce enough data. For the time and since some observations may be merely coincidental we will withdraw the conclusion and delete the sentence.

    

1. The point upon the different role anion and cation size in lines 531-534 should be discussed and documented. The main difference is probably that the cation bear chain substituents having a volume, while the anions have no substituents.

 

This is not a point it is a simple observation. We have rephrased the sentence. Again, they are not enough cases of smectic T phases to support definitive scientific conclusions,

 

1. What are (i) and (ii) in lines 525 and 534 for?

 

Most probably they are remnants of previous versions. The authors thank the reviewer for the correction

 

1. Point in lines 534-535 needs reference.

 

OK

 

1. Point in lines 535-537 is merely related to cross-section discrepancy between chains and ions. This is hardly in the scope of the paper and could either be suppressed or on the contrary maintained with additional explanations.

 

We decided to keep the comment since it can probably help potential readers that are not experts in the field. We agree with the explanation of the reviewer and decided to incorporate it as is in the manuscript in order to honor him for his hard work and constructive comments.

 

1. Statement in lines 538-540 must be supported with literature references or removed.

 

Since the statement does not apply to all the cases we decided to remove it.

Round 2

Reviewer 1 Report

Publish in present form

Reviewer 2 Report

Authors adequately revised their manuscript. I recommend acceptation in present form.