Structural and Antimicrobial Investigation of Some New Nanoparticles Mixed Ligands Metal Complexes of Ethyl 6-Amino-4-(4-chlorophenyl)-5-cyano-2-methyl-4H-pyran-3-carboxylate in Presence of 1,10-Phenanthroline
Round 1
Reviewer 1 Report
The manuscript is based on research in the scientific literature. It presents information the a new series of some biologically active Cr(III), Fe(III), Co(II), Ni(II), Cu(II) and Zn(II) complexes was synthesized from ethyl 6-amino-4-(4-chlorophenyl)-5-cyano-2- methyl-4H-pyran-3-carboxylate (L) in presence of 1,10-phenanthroline monohydrate (Phen). The authors performed spectroscopic and physicochemical techniques to characterize the new mixed metal complexes. The antimicrobial activity of ligands and generated complexes has been tested against G(+ve), G(-ve) bacteria and two fungi strains.
In Figure S3 (supplementary material) missing diagram for Phen.
In general, the quality of the article is good and, overall, the manuscript is interesting to readers. English language and style are good, but there are some minor spelling mistakes. In conclusion, I consider the article could be a useful contribution to the journal. I recommend the manuscript for being published.
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Reviewer 2 Report
The manuscript titled “Structural and antimicrobial investigation of some new nanoparticles mixed ligands metal complexes of Ethyl 6-amino-4-(4-chlorophenyl)-5-cyano-2-methyl-4H-pyran-3-carboxylate in presence of 1,10-phenanthroline” of the authors M. S. El-Attar, S. A. Sadeek, H. A. El-Sayed, H. M: Kamal, H. S. Elshafie in its current form do not fulfill the criteria for publication in Inorganics, and thus must be improved.
In this manuscript, the known ligand was complexed with 3d-metals along with the o-phenanthroline as a co-ligand. The compounds were characterized by many methods to gain insight into their composition, purity, and structure. Given the fact, that there is no SC-XRD here, I must bring up the question was the optimization of the synthetic procedure to obtain single crystals conducted?
The main remarks are:
· The ligand L is not “new” as stated in the Abstract. In the Experimental part, it is said that this ligand is synthesized according to the known procedure. However, its structure is already been published elsewhere and I do not see this reference cited here (Chem. Sel. (2021), 6, 11249, doi:10.1002/slct.202103182).
· The coordination formulas of the complexes should be given earlier, so it would be easier to follow the manuscript. This applies to Table 1. as well.
· Part 2.1. Lines 80-83 are confusing and should be rephrased. The range given contains the values for the ligands, but they are non-electrolytes.
· Part 2.2. The shift of ν(C≡N) band occurs only in complexes 1 and 2 and it is positive. However, in the text, it is stated that this band suffers a negative shift. Please check and discuss further (Inorg. Chem. 37 (1998) 5776, J. Organomet. Chem. 690 (2005) 4908.). If the significant bands are given in the text, maybe Table 2. could be given in the Supplementary Material. The same applies to Table 4 since the thorough discussion and the values are given in the text, as well. Also, why is “br” abbreviation explained in the legend of Table 2. There is no a broad band assigned here?
· Line 108. ν(C≡N) stands instead of ν(C=N)?
· Part 2.5. “Thermal analyses were carried out with the aim to investigate the nature of water in the investigated compounds”. The discussion of the nature of water is not given further in the text, except for line 191 where “lattice water” is mentioned. Please clarify and discuss this further. Melting points were measured, so could they be connected to this part as well?
· Part 2.7. There is no XRD for Phen in Figure 2.
· Part 2.8. should contain comments about the comparative analysis of the activity of the compounds and the activity of the standards given in Figure 3. Are these results expected? Is there a possible explanation for the best activity of complex 3? Lines 288-293 contain the general comment, but there should be a more precise one here.
· Part. 3.4. Since there is no spontaneous oxidation to cobalt(III), even though the reaction was not conducted in the inert atmosphere, this should be explained by the ligand system. Also, are there complexes with similar ligands that stabilize Co(II) in the presence of atmospheric oxygen? How the compounds were stored? Add comments on the solubility of the obtained compounds, please. The temperature of the reaction was lower than the boiling point of the solvent. Is there a particular reason for this? Also, why the reacting solution is so diluted? Is the solubility of the ligand so limited? Have the authors tried the other solvents?
The language quality should be improved, and some sentences rephrased.
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Reviewer 3 Report
The article contains diverse physical and chemical studies of mixed ligands 3d-metal complexes of ethyl 6-amino-4-(4-chlorophenyl)-5-cyano-2-methyl-4H-pyran-3-carboxylate in the presence of 1,10-phenanthroline. However, the main content of the paper is still to study the bactericidal properties of the obtained compounds. Therefore, the authors should comment in more details on why it is the cobalt complex 3 that exhibits the strongest antimicrobial activity. It is this information that will be most important for the reader.
Of the other observed inaccuracies, we note the following.
Why is there two d-d transitions for complex 4 (see Table 3), and only one for all others? How does this complex stand out?
In line 147, the number 2 should be the upper left index.
The article can be published in Inorganics after some revisions.
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Round 2
Reviewer 2 Report
The manuscript titled “Structural and antimicrobial investigation of some new nanoparticles mixed ligands metal complexes of Ethyl 6-amino-4-(4-chlorophenyl)-5-cyano-2-methyl-4H-pyran-3-carboxylate in presence of 1,10-phenanthroline” of the authors M. S. El-Attar, S. A. Sadeek, H. A. El-Sayed, H. M: Kamal, H. S. Elshafie has been improved and could be accepted for publication in Inorganics, after a minor review.
· Abstract: From the first sentence it is not clear if the ligand is a new compound or the already known one. Please try to begin with the second sentence. It is better for the Abstract to begin with what new was done.
· In their response to the remarks, i.e., Q11. the authors have given a list of references with similar ligand system stabilizing Co(II). It would be nice to have this comment along with a few sentences about the synthesis and the solubility of the compounds at the beginning of section 2.
· Line 76. “Elemental analysis and molar conductance” instead of “Elemental and molar conductance”.
· Some typos: line 121 “referred” instead of “refered” and line 132 “synthesized” instead of “synthizied”.
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