Palanquin-Like Cu4Na4 Silsesquioxane Synthesis (via Oxidation of 1,1-bis(Diphenylphosphino)methane), Structure and Catalytic Activity in Alkane or Alcohol Oxidation with Peroxides
, Yan V. Zubavichus 3,4, Lidia S. Shul’pina 1, Elena S. Shubina 1, Mikhail M. Levitsky 1, Nikolay S. Ikonnikov 1, Alexey N. Bilyachenko 1,2,*, Yuriy N. Kozlov 5,6 and Georgiy B. Shul'pin 2,5,6,*Round 1
Reviewer 1 Report
The work by Kulakoa et. al. is condensed in a well written research paper exhaustively documented by a meticulous literature. An article can be formally separated into two parts. The first one describes the synthesis and structural peculiarities of the new heterometallic silsesquioxane cluster. The second one deals with alkanes or alcohols oxidations with peroxide, catalyzed by the new copper cluster. Interestingly, phenylethanol oxidation results in the formation of acetophenone in almost a quantitative yield. In addition, the authors demonstrate that the catalytic transformation of cyclohexane into cyclohexanol can be achieved with moderate yields. However, it is not straightforward why the authors decided to study the selected complex as a catalyst for oxidation reactions. This should be mentioned in the manuscript. The authors might also consider to comment on the role of the nitric acid additive in oxidation reactions. The sentence on the lines 143-144 does not make any sense, it should be a typo mistake. Overall, I am happy to recommend the acceptance of this manuscript after a minor revision.
Author Response
1) Reviewer 1 wrote: However, it is not straightforward why the authors decided to study the selected complex as a catalyst for oxidation reactions. This should be mentioned in the manuscript.
Response by authors: we mentioned this in the text : Catalysts of this type have been shown to exhibit high catalytic activity. It was interesting to introduce phosphorus atoms into the catalyst structure.
2) The authors might also consider to comment on the role of the nitric acid additive in oxidation reactions.
Response by authors: we corrected to: We assume that added nitric acid induces the transformation of the catalyst into an active form.
3) The sentence on the lines 143-144 does not make any sense, it should be a typo mistake.
Response by authors: we corrected to:
Complex 1 has been found to efficiently catalyze transformation of alcohols into corresponding ketones by the oxidation with tert-butyl hydroperoxide (Figure 8).
Reviewer 2 Report
This manuscript reporting on the facile synthesis, structure and catalytic application of a cage-like polymetal-based catalyst might be of interest in catalytic chemistry, however, major revision is indispensable prior to final acceptance. The main structural characteristics inluding the deviation from the square planar arrangement of the ligands coordinated to copper(II) ions should be discussed in the body text. The involvement of acetonitrile in the oxidative transformations needs more detailed interpretation with special regard to the specification of the product formed in the competitive reaction. Accordingly, experiments carried out in alternative solvents with higher resistance to oxidation (e.g. nitromethane) also seem to be necessary to increase the efficiency of the presented methodology. English also needs substantial revision throughout the manuscript.
Author Response
1) The main structural characteristics inluding the deviation from the square planar arrangement of the ligands coordinated to copper(II) ions should be discussed in the body text.
Respose of authors:
2) The involvement of acetonitrile in the oxidative transformations needs more detailed interpretation with special regard to the specification of the product formed in the competitive reaction. Accordingly, experiments carried out in alternative solvents with higher resistance to oxidation (e.g. nitromethane) also seem to be necessary to increase the efficiency of the presented methodology.
Respose of the authors:
we plan to study alternative solvents (nitromethane, water and alcohols) in alkane oxidatios in the nearest future.
at the moment we start sistematic detal
Round 2
Reviewer 2 Report
Taking the response of authors into account, the revised version of the manuscript can be accepted for publication.
