Circular Dichroism Spectroscopic Studies on Solution Chemistry of M(II)-Monensinates in Their Competition Reactions
Round 1
Reviewer 1 Report
This study dealt with formation of complexes of monensic acid A by several divalent metal ions.
The significance and results were fine, so it should be published in Inorganics basically.
However, some points should be explained more closely before acceptance.
(1) The advantage of extended wavelength of CD spectra should be explained. Usually, synchrotron has merit of short wavelength region for secondary structures of proteins. Why did you mention for organic ligands of small molecule? NIR and visible region "similarly" changed CD spectra by addition of metal ions. If CD (not UV-vis) spectra have isosbestic points, what is its meaning?
(2) MRA analysis of CD spectra by a program is regarded as a "black box". Please add explanation briefly from the viewpoint of analytical chmistry for equilibrium of solutions.
(Minor point)
L134: Remove error massage.
L163: a new spectral patter -> a new spectral pattern (? please conifrm)
That's all.
Author Response
Please, see the attached document.
Author Response File: 
Author Response.pdf
Reviewer 2 Report
The paper is devoted to the application of CD method to the investigation of complexation properties in water solution. The Idea is well interesting since it allows to work with “colorless” complexes that could not be investigated by traditional UV-VIS methods. There are few minor remarks that should be discussed:
1. Technical remarks – line 135, line 179. The broken reference.
2. The evaluation of spectral data by MRA program. Agree, in can be seen from the presented pictures that two complex species are enough to describe the equilibriums. But probably authors can add some statistical data to the text? I mean the statistical analysis of root square deviation change by F – test.
3. The presence of the water in complexes similar to the investigated was earlier proved by solid state single crystal XRD. Still, it is not obvious that in the solutions these complexes will have the same structure. Is there any proves for the presence of water molecules in [M(Mon)(H2O)] or [M(Mon)2(H2O)2]. The CD data does not allow to determine it and it should be discussed somehow.
Author Response
Please see the attached document.
Author Response File: Author Response.pdf
