Peer review of: Evolution from unimolecular to colloidal-quantum-dot-like character in chlorine or zinc incorporate (2020)

Reviewers' comments: 

Reviewer #1 (Remarks to the Author): 

This report from Kim, Kim, and coworkers details the synthesis and interconversion of a family of indium 
phosphide clusters related to a structurally characterized intermediate (386-InP MSC) previously 
identified by Cossairt and coworkers. This report details how surface chemistry, in particular the 
introduction of chloride, and the incorporation of zinc into the cluster lattice alters the optical and 
structural properties of the resulting clusters. All of the materials are carefully characterized by NMR, 
XRD, Raman, and composition analysis. The connection between all of the reactions and structures is 
relatively clear, despite the complicated nature of the overall system and the nuance of the individual 
reactions. Overall the work paints a picture of the versatility of InP cluster synthesis and interconversion 
and suggests that surface chemistry and doping are tunable parameters in altering the structure and 
properties of these clusters. I believe the work merits publication. Based on the description of papers 
suitable for Nature Communications, which specifies the journal as a venue for comprehensive, rigorous 
and elegant studies that are of specialist interest, I think this study fits the bill. A few minor comments 
are suggested upon revision prior to publication as noted below. 

1. Page 3: The statement "MSCs that host heterogeneous atoms have not been studied in detail" is not 
clear to me. Specifically the meaning of the word heterogeneous seems ambiguous. Cluster doping - the 
incorporation of exogenous cations, for example, has significant precedent: 
https://pubs.acs.org/doi/abs/10.1021/acsnano.6b03348, 
http://pubs.acs.org/doi/10.1021/acs.chemmater.7b03075, 
https://pubs.acs.org/doi/10.1021/acs.chemmater.8b01482, are just a few examples. 

2. Page 8: The abbreviation "OAs" is used - I think the authors are reviewing to oleic acid here. 
Elsewhere they have used "OA" to refer to that species. This typo should be corrected. Also, it would 
help to distinguish between oleate (deprotonated) and oleic acid in the case of these abbreaviations. 
HOA and OA for example. 

3. EDX appears to be the primary composition method used in this manuscript. Was the EDX acquired on 
the TEM samples? It seems surprising to me that the clusters would survive under the harsh beam 
conditions needed to acquire EDX analysis. It is more typical to assess compositions by a method like 
ICP-MS (or OES/AES). Do those data compare favorably with the observed EDX numbers? Overall the 
reported values seem reasonable and consistent with what others have seen, but I am surprised the 
data are reliable for such fragile objects. 

4. What was the rationale for adding ODPA in the synthesis of the zinc containing clusters? This seems 
like a non-intuitive choice and as a reader I would appreciate understanding what the authors were 
thinking there. What happens when no ODPA is used? Given the precedent for ODPA-capped InP 
clusters reported in reference 6, do the authors have controls that help us understand how much of the 
optical properties come from ligand effects versus the incorporation of zinc? 


Reviewer #2 (Remarks to the Author): 

In this manuscript, the authors reported the synthetic pathways of doped InP clusters. By introducing Cl 
atom or Zn atom either in situ or in post synthesis step, two families of InP clusters InP:Cl and InP:Zn 
with different size have been prepared. Furthermore, in an individual family, the authors observed the 
conversion of clusters between different sizes. Although, the authors did present a large amount of 
results in this manuscript, the novlty is still missing. This manucript looks more like a following work of 
the one published on JACS in 2016 (JACS, 2016, 138, 1510). Besides, the characterization is not 
complete. For example, what is the actual crytal structures of the new InP clusters? How does the Cl or 
Zn bind with clusters, on the surface or in the cluster? Is the method present here a general method and 
does it works for other cluster system besides InP? Therefore, with these concerns in my mind, I don't 
recommend to publish this manucript on Nature Communuication. 



Reviewer #3 (Remarks to the Author): 

Manuscript NCOMMS-19-31129 entitled “Evolution Series from Uni-Molecule-like to Colloidal-Quantum-
Dot like Characters in Chlorine or Zinc Incorporated Indium Phosphide Magic Size Clusters” by Dongho 
Kim, Sungjee Kim, et al, presents the syntheses of InP MSC-386, Cl-incorporated InP MSC-360, Cl-
incorporated InP MSC-399, Zn-incorporated InP MSC-360, Zn-incorporated InP MSC-408, and Zn-
incorporated InP MSC-393. For the Cl incorporated MSCs, they were synthesized directly or via 
“sequential conversion” reactions with InP MSC-386. For the Zn incorporated MSCs, they were 
synthesized directly or via “sequential conversion” reactions with Zn-incorporated InP MSC-360. The 
evolution from Zn-incorporated InP MSC-408 to Zn-incorporated InP MSC-393 was claimed. These 
experimental results seem to be interesting. 

Also, the authors claimed, based on XRD and Raman, that the structures of Cl-incorporated InP MSC-
399, Zn-incorporated InP MSC-408, and Zn-incorporated InP MSC-393 are close the QD zinc-blende 
structure. The structures of Cl-incorporated InP MSC-360, Zn-incorporated InP MSC-360 are similar to 
that of InP MSC-386. The structural studies do not seem to be convincing. 

The authors concluded that “Our findings highlight the mechanistic insight that the growth of QDs can 
be understood as multi-step sequential conversions through different MSCs or evolutions of MSCs.” The 
key conclusion does not seem to be connected with the experimental results. 

If the authors provide the evolution pathways in a convincing and logic way, from InP MSC-386 to Cl-
incorporated InP MSC-360 and to Cl-incorporated InP MSC-399, and from Zn-incorporated InP MSC-360 
to Zn-incorporated InP MSC-408 and to Zn-incorporated InP MSC-393, the study might be publishable. 

1. What is the composition-structure-property relationship between Cl-incorporated InP MSC-360 and 
Cl-incorporated InP MSC-399? 
2. What is the composition-structure-property relationship for Zn-incorporated InP MSC-360, Zn-
incorporated InP MSC-408, and Zn-incorporated InP MSC-393? 
3. Is it possible to provide the very experimental evidence on the transformation of Cl-incorporated InP 
MSC-399 to QDs, and Zn-incorporated InP MSC-408 to Zn-incorporated InP MSC-393 to QDs? 
4. On Page 17, the authors wrote for Figure S18 that the “a continuous blue-shift indicates the existence 
of numerous intermediate species between Zn-incorporated InP MSC-408 and Zn-incorporated InP MSC-
393”. What is the nature of the evolution? The authors claimed that the two clusters have different 
compositions. 
5. On Page 21, the authors should provide in depth explanations on how to control the Zn atom to be on 
the surface, and the definition of “periphery” (does not affect the absorption peak position) vs 
“quantum-confined core” (does affect the absorption peak position). What is the composition difference 
between ODPA-capped InP MSC-397 and Zn-incorporated InP MSC-393? For Zn-incorporated InP MSC-
360, 408, and 393, do they have different cores? 
6. What is the composition-structure-property relationship for MA-capped InP MSC-386 (exhibiting one 
absorption singlet) and ODPA-capped InP MSC-397 (displaying one absorption doublet)? 
7. For the InP MSC-386 to Cl-incorporated InP MSC-360 evolution shown in Figure 1c at 80 C, the 
authors attributed the absorption peaking at 416 nm as one intermediate species (416-IS). The half 
width at half-maximum (HWHM) of “416-IS” is 20 nm, the same as that of Cl-incorporated InP MSC-360. 
Can this intermediate be Cl-incorporated InP MSC-416? 
8. For the evolution from InP MSC-386 to Cl-incorporated InP MSC-360 shown in Figure S3b at 50 C and 
Figure S3c at 25 C, the authors claimed (Lines 141 to 142 on Page 6) “intermediates which have not 
been properly detected”. Regarding the evolution from InP MSC-386 to Cl-incorporated InP MSC-360 at 
these different temperatures studied as shown in Figures 1c, S3b, and S3c, any explanation why the 
experimental observation on “intermediates” is influenced by the temperatures? 
9. For the Page 9 equation, any numbers can be assigned to x? 
10. For the Page 9 equation, if y = 0, the reaction becomes an anionic exchange reaction between P and 
Cl. Any explanation? 
11. All the figures should be improved, including the color usage, the legend font size, and dpi. For 
example, the Figure 1 legend font size is far too small. 
12. The format of the refs should be edited according to the magazine required format.