[6-(Thiophen-2-yl)-2,2′-bipyridine]bis(triphenylphosphine) Copper(I) Tetrafluoroborate

Round 1

Reviewer 1 Report

This paper gives a clear and readable account of a structural and optical study of a photoluminescent Cu(I) coordination compound.  The introduction makes a clear case for undertaking the project and appears to reference an adequate number of related studies.  Descriptions of the synthesis, crystal structure and optical measurements are easy to follow, and the diagrams are mostly very clear.  Chemical analyses, and details of the ¹H nmr and the ir absorption spectra are welcome.

I have a couple of minor points on the X-ray structure and its presentation that I would like to see addressed:  

a) Fig 5: The view of the ligand is perhaps not the best - if the orientation were to be tilted slightly, the label N(2) could be more clearly associated with the N(2) atom; 

b) I was surprised to see 10-12 lower angle reflections missing from the copious X-ray data, some of them with large calculated F values.  Low angle data are important and it's not clear to me why they are not there.  If they cannot be seen, maybe a short sentence giving the explanation could be included. 

c) Just a comment:  25^o for theta_max for such a strongly diffracting crystal seems lower than it need be.

Author Response

We would like to thank reviewer 1 for the time and effort to evaluate our ms, His/her comments were valuable

Revision queries

1. a) Fig 5: The view of the ligand is perhaps not the best - if the orientation were to be tilted slightly, the label N(2) could be more clearly associated with the N(2) atom;

 A new fig. 5 is provided, where the heterocyclic ligand is clearly shown.

1. b) I was surprised to see 10-12 lower angle reflections missing from the copious X-ray data, some of them with large calculated F values. Low angle data are important and it's not clear to me why they are not there. If they cannot be seen, maybe a short sentence giving the explanation could be included.

 Only a limited number of low-angle reflections is missing. This is likely due to the beam stop. By using Mo radiation and the geometry of our goniometer, this happens quite often. The sentence “A few reflections bellow theta(min) were missing, probably because they are affected by the beam stop.”  has been added in the experimental part to address this issue.

1. c) Just a comment: 25o for thetamax for such a strongly diffracting crystal seems lower than it need be.

The data were deliberately cut with OMIT 0 50 to achieve maximum resolution 0.84 Å.There is no need for higher resolution data for the purpose of the present study.

Reviewer 2 Report

The authors report the structure of a copper(I) compound featuring a thiophene-substituted 2,2-bipyridene ligand. The authors provide diffuse reflectance UV-vis, infrared, and NMR data as well as analytical data including elemental analysis and mass spectrometry to support the formulation given. Their assignments are consistent with data provided. This broad family of compounds, (bpy)CuL+ are well known in the literature. This appears to be a unique derivative and structure, and the data that the authors have provided is also consistent within the cannon of these compounds. The compound is structurally characterized, and the solution is appropriate for the system. No aspect of the solution raises any concerns. Finally, the authors provide solid state luminescence data as an interesting final feature of this compound. The quantum yield is not remarkable (2.6%) but not inconsistent with related compounds. The presentation of the article is clear and easy to follow. My compliments to the authors--I support publication in its current form.

Author Response

We would like to thank reviewer 2 for his/her comments. We are grateful for the time and effort spent reviewing our manuscript