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

[EN] 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 H-1 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-(t)butylphenylnitrone indicate the generation of (BuOO)-Bu-t. and (BuO center dot)-Bu-t under the reaction conditions. The scope of MIL-125(Ti)-NH2-Sal-Cu as oxidation catalyst by (BuOOH)-Bu-t was studied for benzyl alcohol as well as alicyclic and aliphatic alcohols and ethylbenzene. (C) 2018 Elsevier Inc. All rights reserved. Financial support by the Spanish Ministry of Economy and Competitiveness (Severo Ochoa) CTQ2014-53292-R is gratefully acknowledged. Generalidad Valenciana is also thanked for funding (Prometeo 2017/063). S.D., A.R.O., D.A., and R.G-V thank H.G., S.N. and M.A., S.D., D.A., and R.G-V gratefully acknowledge financial support from Bu-Ali Sina University. S.N. thanks financial support by the Fundacion Ramon Areces (XVIII Concurso Nacional para la Adjudicacion de Ayudas a la Investigacion en Ciencias de la Vida y de la Materia, 2016). Daliran, S.; Santiago-Portillo, A.; Navalón Oltra, S.; Reza Oveisi, A.; Alvaro Rodríguez, MM.; Ghorbani-Vaghei, R.; Azarifar, D... (2018). Cu(II)-Schiff base covalently anchored to MIL-125(Ti)-NH2 as heterogeneous catalyst for oxidation reactions. Journal of Colloid and Interface Science. 532:700-710. https://doi.org/10.1016/j.jcis.2018.07.140