Chaaban et al. prepared an asymmetric N-rim partially substituted calix[4]pyrrole and investigated its binding affinity with Ag(I) and Hg(II) ions. Overall, the authors carried out interesting research work. The synthesis part is supported by NMR and mass analysis (microanalysis (for CP) and FAB-MS (for CPII)). Then metal complexation with CPII receptor was systematically studied with H-NMR, SEM-EDX, FTIR, XPS, and molecular simulation and modeling study.

1) The manuscript title attracts the readers to curiously read this research work, however, the introduction part is not well-written. The first paragraph of the introduction part is confusing. The authors shall make it simple to talk about the toxicity of Ag(I) ions and why they need to be monitored. Then the second and third paragraph of the introduction describes the reported host molecules. Even though many papers are reporting Ag(I) receptors, the latest used reference is 2011. There is no explanation of the importance of the N-diethyl-thioamide group and why the tri-substituted calix[4]pyrrole is designed. Therefore, the introduction part should be improved.

2) The x-axis of SEM images in Figure 3 is not the same. It should be unified. Furthermore, the elemental mapping was monitored for 2 locations on CPII and CPII treated with Ag(I). Why the elemental monitoring was conducted only once for CPII treated with Hg(II)? Three monitored locations for each sample will increase the validity of the measurement.

3) Figure 4 is also confusing. In Figure 2, the authors used vertical axis gridline for easy recognition. However, the same treatment was not found in Figure 4. In Figure 2, the authors did not number the NMR spectra, however, the NMR spectra of Figure 4 were numbered. Furthermore, the x-axis of Figure 4a (0-12 ppm) was not the same as Figure 4b (0-16 ppm). No signal was found at chemical shift more than 10 ppm thus I recommend taking the same x-axis (0-10 ppm) as displayed in Figure 2.

4) The authors stated that “Therefore, the findings reveal that CPII displays a high selectivity for the Ag(I) cation and these findings opens the need for future studies on its applications” on the first paragraph on page 4831, however, the authors only evaluated Ag(I) and Hg(II) cations in this study. I suggest removing that sentence because additional investigation for other metal ions (such as K(I), Pb(II), etc.) with similar size and similar charge with Ag(I) ions should be carried out to clarify this statement.

5) The FTIR spectra of CPII and CPII treated with Hg(II) should be in one image. The x-axis was not the same making they are not easily compared by the readers. And why the FTIR spectra of CPII treated with Ag(I) was not shown? It is better to show the FTIR spectra of CPII, CPII treated with Ag(I), and CPII treated with Hg(II) in one image as Figure 5. FTIR data should be also added for CPII compound characterization in the experimental section.

Minor correction: The second paragraph of 2.2. Synthesis and …….., CP ethanol (50 cm3) -> “3” should be in superscript