Cu(II)-Schiff base covalently anchored to MIL-125(Ti)-NH2 as heterogeneous catalyst for oxidation reactions

Saba Daliran; Andrea Santiago-Portillo; Sergio Navalón; Ali Reza Oveisi; Mercedes Álvaro; Ramin Ghorbani-Vaghei; Davood Azarifar; Hermenegildo García

doi:10.1016/j.jcis.2018.07.140

Cu(II)-Schiff base covalently anchored to MIL-125(Ti)-NH₂ as heterogeneous catalyst for oxidation reactions

J Colloid Interface Sci. 2018 Dec 15:532:700-710. doi: 10.1016/j.jcis.2018.07.140. Epub 2018 Aug 1.

Authors

Saba Daliran¹, Andrea Santiago-Portillo², Sergio Navalón³, Ali Reza Oveisi⁴, Mercedes Álvaro², Ramin Ghorbani-Vaghei⁵, Davood Azarifar⁵, Hermenegildo García⁶

Affiliations

¹ Faculty of Chemistry, Bu-Ali Sina University, P.O. Box: 6517838683, Hamedan, Iran; Departamento de Química and Instituto de Tecnología Química CSIC-UPV, Universitat Politècnica de València, Av. de los Naranjos s/n, 46022 Valencia, Spain.
² Departamento de Química and Instituto de Tecnología Química CSIC-UPV, Universitat Politècnica de València, Av. de los Naranjos s/n, 46022 Valencia, Spain.
³ Departamento de Química and Instituto de Tecnología Química CSIC-UPV, Universitat Politècnica de València, Av. de los Naranjos s/n, 46022 Valencia, Spain. Electronic address: sernaol@doctor.upv.es.
⁴ Department of Chemistry, University of Zabol, P.O. Box: 98615-538, Zabol, Iran.
⁵ Faculty of Chemistry, Bu-Ali Sina University, P.O. Box: 6517838683, Hamedan, Iran.
⁶ Departamento de Química and Instituto de Tecnología Química CSIC-UPV, Universitat Politècnica de València, Av. de los Naranjos s/n, 46022 Valencia, Spain; Center of Excellence for Advanced Materials Research, King Abdulaziz University, Jeddah, Saudi Arabia. Electronic address: hgarcia@qim.upv.es.

PMID: 30121522
DOI: 10.1016/j.jcis.2018.07.140

Abstract

MIL-125(Ti)-NH₂ has been modified by reaction of salicylaldehyde with the terephthalate amino groups to form a salicylideneimine that act as ligand of Cu²⁺. The success of the postsynthetic modification was assessed by FTIR spectroscopy of the MIL-125(Ti)-NH₂-Sal-Cu and by analysis by ¹H NMR spectroscopy of the organic linkers upon dissolution of MIL-125(Ti)-NH₂-Sal-Cu. In comparison with parent MIL-125(Ti)-NH₂ and MIL-125(Ti)-NH₂-Sal, that exhibit a poor activity, the presence of the Cu-Schiff base complex in MIL-125(Ti)-NH₂-Sal-Cu catalyst for the oxidation of 1-phenylethanol by tert-butylhydroperoxyde (TBHP, 3 eq.) increases notably the catalytic activity. Hot filtration test and reusability experiments confirm that the process is heterogeneous and that MIL-125(Ti)-NH₂-Sal-Cu is stable under the reaction conditions. Quenching studies and EPR spectra using N-^tbutylphenylnitrone indicate the generation of ^tBuOO and ^tBuO under the reaction conditions. The scope of MIL-125(Ti)-NH₂-Sal-Cu as oxidation catalyst by ^tBuOOH was studied for benzyl alcohol as well as alicyclic and aliphatic alcohols and ethylbenzene.

Keywords: Heterogeneous catalysis; Metal-organic frameworks: Cu(II) Schiff-base complex; Tert-butylhydroperoxyde.