Dear Dr. Kumar

Thank you for your attention. This is a big query for us too as well as for referees who raised some comment in this matter. We also have some serious query about active species in this catalytic system. High catalytic activity was observed for title catalyst even after several recycling while simple salts of Mo(VI) showed low activity and undesired selectivity. More important is a minor change in characteristic bands in Raman spectra. A sharp peak in 876 cm-1 shifted to 880 cm-1 in reused catalyst, also a sharp peak in 373 cm-1 shifted to 379 cm-1 in reused catalyst which can be rationalized to stability of catalyst . Nevertheless, UV-vis spectra showed a peak at 310 nm that related to Mo-peroxo species. Some experts believed that some Mo (V) centers converted to Mo(VI) peroxo making main change to UV-vis but minor changes in Raman spectra. Some others suggests decomposition of catalyst, but there are not sufficient evidence to support both claim until now. Some samples will be sent to X-ray analysis. Regardingly, no claim on stability of catalyst was mentioned out throughout the title paper and this is under deep investigation in our laboratory on different Keplerates. Your comments in this matter is greatly appreciated.

Yours Sincerely

Prof. A. Rezaeifard

Catalysis Research Lab.

University of Birjand