Matere Bonds in Technetium Compounds: CSD Survey and Theoretical Considerations
Round 1
Reviewer 1 Report
I have no objections to the manuscript.
However, full method names QTAIM or NBO or CSD database as proper names could be written with capital letter.
Author Response
First, we would like to thank this referee for his/her careful reading of the manuscript, corrections and suggestions. The “point-by-point” replies follow:
I have no objections to the manuscript.
However, full method names QTAIM or NBO or CSD database as proper names could be written with capital letter.
Reply: Done
Reviewer 2 Report
The study aims at characterizing matere bonds that involve Tc in four oxidation states and "reports crystallographic and theoretical evidences that consistently prove the matere bond interaction between technetium derivatives in oxidation states +7, +6, +5 and +3 and lone pair donor atoms belonging to anions, cations and Lewis bases."
It is scientifically sound and shows some types of matere bonds that have not been previously described. My suggestion is to include this statement in the abstract, to make the article more appealing to potential readers.
There are some minor errors originated by using Spanish words instead of English, such as "nitrido" in line 111 and others. In line 59, the color is "red", not "read".
Author Response
First, we would like to thank this referee for his/her careful reading of the manuscript, corrections and suggestions. The “point-by-point” replies follow:
The study aims at characterizing matere bonds that involve Tc in four oxidation states and "reports crystallographic and theoretical evidences that consistently prove the matere bond interaction between technetium derivatives in oxidation states +7, +6, +5 and +3 and lone pair donor atoms belonging to anions, cations and Lewis bases."
It is scientifically sound and shows some types of matere bonds that have not been previously described. My suggestion is to include this statement in the abstract, to make the article more appealing to potential readers.
Reply: Done
There are some minor errors originated by using Spanish words instead of English, such as "nitrido" in line 111 and others. In line 59, the color is "red", not "read".
Reply: Thank you for these corrections. We have checked the manuscript and corrected these and other typos. To our knowledge, nitrido is correct in English to name the ≡N ligand, see for instance: Askevold, B., Nieto, J., Tussupbayev, S. et al. Ammonia formation by metal–ligand cooperative hydrogenolysis of a nitrido ligand. Nature Chem 3, 532–537 (2011). https://doi.org/10.1038/nchem.1051
Reviewer 3 Report
The submitted manuscript is nicely prepared and the discussion is interesting. However, the amount of new information is limited-the Authors focus on the previously reported structures and perform some basic calculations, without even geometry optimization. I have some questions and suggestions about this work, they can be found below.
Line 40- “several” – exactly how many?
Line 46, not “methodologies” but “methods”
Line 101, those values are huge, but can the energy of MaB be calculated, somehow?
Page 4, I think it would be interesting to calculate, i.e. in Gaussian, in vacuo, the geometry and energy of the homodimer made of two tetrachloro-nitrido-technetate anion. Will they form a stable dimer or rather dissociate? This seems to be a perfect example to study the MaB as the cation-anion interactions in this crystal are pretty weak.
Figure 5, please use different colors for S and Au
In the figure captions the color descriptions of atoms of particular elements should be explained
A supplementary information file should be created to present the details of the structures analyzed in this work, i.e. unit cell dimensions, Z, crystal space group, molecular formula etc.
Calculations: Why the Authors have performed the calculations on dimers, trimers etc. since the Turbomole allows the calculations of the periodic structures?
Calculations: In my honest opinion, to increase the scientific value of the manuscript, the Authors should compare the “unoptimized” (single-point) and fully optimized (atomic positions + unit cell dimensions) structures, in terms of NBO, QTAIM and structural differences, with the main emphasis on the bonds in which Tc is involved. The “SP” calculations results can provide the inaccurate results as the structures deposited in CCDC have various accuracy, R, etc. Therefore any DFT calculations on the nonoptimized structures should be avoided.
Author Response
First, we would like to thank this referee for his/her careful reading of the manuscript, corrections and suggestions. The “point-by-point” replies follow:
The submitted manuscript is nicely prepared and the discussion is interesting. However, the amount of new information is limited-the Authors focus on the previously reported structures and perform some basic calculations, without even geometry optimization. I have some questions and suggestions about this work, they can be found below.
Line 40- “several” – exactly how many?
Reply: Several has been replaced by eight!
Line 46, not “methodologies” but “methods”
Reply: Fixed, thanks!
Line 101, those values are huge, but can the energy of MaB be calculated, somehow?
Reply: In some neutral systems the energies are quite modest (like OSICUP) giving some idea regarding the energy of the MaB (for this particular case around 5.5 kcal/mol). The E(2) energies also provide some information regarding the strength of the interactions.
Page 4, I think it would be interesting to calculate, i.e. in Gaussian, in vacuo, the geometry and energy of the homodimer made of two tetrachloro-nitrido-technetate anion. Will they form a stable dimer or rather dissociate? This seems to be a perfect example to study the MaB as the cation-anion interactions in this crystal are pretty weak.
Reply: In the gas phase this homodimer dissociates, but it does not in water. This has been commented in the new section of the manuscript (see 3.5).
Figure 5, please use different colors for S and Au
Reply: Done
In the figure captions the color descriptions of atoms of particular elements should be explained
Reply: Done
A supplementary information file should be created to present the details of the structures analyzed in this work, i.e. unit cell dimensions, Z, crystal space group, molecular formula etc.
Reply: The ESI has been done as requested
Calculations: Why the Authors have performed the calculations on dimers, trimers etc. since the Turbomole allows the calculations of the periodic structures?
Reply: Our version of Turbomole does not allow performing optimizations using periodic bondary conditions. Please note that we are interested in analyzing the interactions as they stand in the solid state and not in the geometry of fully optimized complexes. This methodology was used in the original publication of matere bonds (ChemPhysChem, 2021, 22, 2281–2285)
Calculations: In my honest opinion, to increase the scientific value of the manuscript, the Authors should compare the “unoptimized” (single-point) and fully optimized (atomic positions + unit cell dimensions) structures, in terms of NBO, QTAIM and structural differences, with the main emphasis on the bonds in which Tc is involved. The “SP” calculations results can provide the inaccurate results as the structures deposited in CCDC have various accuracy, R, etc. Therefore any DFT calculations on the nonoptimized structures should be avoided.
Reply: We agree with the referee. We will intend to do so in a future publication. This journal is crystallographic and this manuscript is more focused on giving a survey of X-ray structures and prove the existence of the matere bond by QTAIM/NCIplot and NBO analysis. To increase the computational weight of the manuscript by adding additional calculations is likely not adequate for the readership of this journal. Please also note that the editor has given only one week to complete the revision, so it is not possible to repeat study in such short period of time. Also note that we have performed the optimization of two dimers to provide reliability to the study using X-ray geometries, see new section 3.5.
Round 2
Reviewer 3 Report
The Authors have made the requested corrections. This version can be accepted as it is.
