Pentapotassium Bis(hydrogenphospate) Dihydrogenphospate Monohydrate

Round 1

Reviewer 1 Report

This paper is of marginal interest, solely because it is a new and interesting phosphate compound.  Part of the "marginal" nature comes from the compound coming out of a solution "by accident" and not being what the study intended to show.  As such, there is no rational experimental discussion leading to the compound.  While there is nothing wrong with room temperature structures, the value of this paper would have been elevated had this analysis been carried out at 100K instead of 297 - the H-bonding would perhaps have been more clearly determined and H-bonding here is very important.  (Note the number of C level issues in the checkcif file.). 

Overall, it is of minimal interest, but of interest nonetheless and worthy of a brief publication.

Author Response

We thank the referee for its time and effort.

Regarding the suggestion for low temperature measurements:

Given the excellent data quality already at RT, low temperature measurements won't improve the structure much. The hydrogen atoms were already visible in the electron density maps at RT and the O-H distances were refined. The 'short' observed OH distances are likely caused by libration, low temperature measurements might counteract this effect a little, but will likely result in overall shorter OH bonds. Overall similar OH bonds might be found. Distance restraints could have been applied to remove the C-Alerts, but this would result in another alert that the OH distances were not allowed to refine.

Reviewer 2 Report

It is a nice communication of a new structure.

I see some small problems with the nomenclature/wording.

It is formally a double salt to my point of view.

At one point of the MS the sysematic name should be given:

pentapotassium bis(hydrogenphospate) dihydrogenphospate monohydrate

Don't use the term units if it is an anion. 

Perhaps you should do not use upper case format within a sentence even if it is a compound name.

Author Response

We thank the referee for its time and effort.

The term double salt as well as the full name were added.

Where unit referred to the entire anion it was replaced by 'anion'

Compound names in the middle of a sentence were written with small caps.