Diisopropyl(6-(phenyl(phenylthio)arsaneyl)-1,2-dihydroacenaphthylen-5-yl)phosphane
Round 1
Reviewer 1 Report
Comments and Suggestions for AuthorsThe preparation and structural characterization of novel compound 4 has been carried out very thoroughly and nicely documented in this article. The structural identity is beyond doubt. However, I do not agree with the presence of a pnictogen (As-P) bond in compound 4.
A closer look at the crystal structure of 4 reveals As-C-C and P-C-C angles very close to 120°, actually the P1-C9-C10 angle and the As1-C1-C10 angles are 118.5° and 122.7°, while P1-C9-C8 and As1-C1-C2 angles amount to 122.4° and 119.1° and are hence very close to ideal sp2 hybridization of C1 and C9. In my eyes, these angles are relevant with respect to a potential bond between As1 and P1. If the pnictogens would form a chemical in 4, I would expect them to approach each other more closely, resulting also in a distorted geometry of the Pn-C-C angles with values significantly below 120°. In AcenapPPh2AsCl2 (Emanuel Hupf, Enno Lork, Stefan Mebs, Lilianna Chęcińska, Jens Beckmann, Organometallics, 2014, 33, 7247), the respective angles are 116° and 112°, in compound 2a 118° and 112° are found. Similar values significantly deviating from 120 for P1-C-C are found in all examples with a clear P-As bond.
Angles around P1 in 4 amount to 312°, while in the C-P-C angles in Acenap compounds with As-P bonds typically sum up to values around 325-330°.
Overall, I do not see experimental evidence for a significant P-As bonding interaction in 4.
However, in silico methods - particularly bond and ring critical point analyses of the Laplacian - should help answering the question of a potential pnictogen bond in 4. I strongly suggest to carry out theoretical investigations!
Author Response
Please see the attachment.
Author Response File: 
Author Response.pdf
Reviewer 2 Report
Comments and Suggestions for AuthorsIn the manuscript entitled “Diisopro-pyl(6-(phenyl(phenylthio)arsaneyl)-1,2-dihydroacenaphthylen-5-yl)phosphane” the authors describe the synthesis and structural characterization of the title compound using SCXRD and NMR methods. The crystal structures have been correctly solved and refined (CHECKCIF shows no serious alerts), and the results are clearly presented. The conclusions are consistent with the presented data, and the references are appropriate.
I recommend the manuscript for publication in Molbank after minor revision.
Specific comments:
1. In my opinion, Figure 1 should be labeled as Scheme 1, and the remaining Schemes and Figures should be renumbered accordingly.
2. Figure 2 should be divided into two separate parts labeled (a) and (b), and each part should be clearly described in the figure caption to indicate what is shown in each panel. In addition, the probability level at which the displacement ellipsoids are drawn should be specified.
3. Table 1 should be divided into three separate sections: bond lengths, angles, and out-of-plane displacements. In addition, the table title should be changed to “Selected geometric parameters for 4”, since out-of-plane displacement is not a bond length.
4. In Ref. 1, the journal title should be corrected to “Chemistry-A European Journal” instead of “Chemistry-a European Journal”. In addition, in Ref. 4, the full journal name should be provided.
Author Response
Please see the attachment.
Author Response File: Author Response.pdf
Round 2
Reviewer 1 Report
Comments and Suggestions for AuthorsWhile the matter of a pnictogen bond between As and P remains a matter of debate, I do not oppose acceptance of the manuscript in its present form. The structural characterisation was done very carefully, all spectra and the crystal data are state of the art. Therefore, I support the acceptance of the manuscript in its current state.
