New Trendy Magnetic C-Scorpionate Iron Catalyst and Its Performance towards Cyclohexane Oxidation

Ana Ribeiro, Inês Matias, Elisabete Alegria, Ana Ferraria, Ana Botelho do Rego, Armando Pombeiro, Luísa Martins
2018 Catalysts  
For the first time, a magnetic C-scorpionate catalyst was prepared from the iron(II) complex [FeCl 2 {κ 3 -HC(pz) 3 }] (pz = pyrazol-1-yl) and ferrite, using the sustainable mechanochemical synthetic procedure. Its catalytic activity for the cyclohexane oxidation with tert-butyl hydroperoxide (TBHP) was evaluated in different conditions, namely under microwave irradiation and under the effect of an external magnetic field. The use of such magnetic conditions significantly shifted the catalyst
more » ... fted the catalyst alcohol/ketone selectivity, thus revealing a promising, easy new protocol for tuning selectivity in important catalytic processes. 2 of 11 catalyst (e.g., its recyclability and reuse by easy magnetic separation) prepared by an eco-friendly route. Moreover, we also aimed at an evaluation of the effect of an external magnetic field on the catalytic performance of our new magnetic material. To our knowledge, this is the first time that the successful preparation of a magnetic scorpionate catalyst and the use of an external magnetic field for tuning the oxidation of alkanes has been reported. Results and Discussion The iron(II) complex [FeCl 2 {κ 3 -HC(pz) 3 }] (1, pz = pyrazol-1-yl) was synthesized according to a reported procedure [18] and characterized by spectroscopic and analytic techniques. The new magnetic iron catalyst (2) was prepared by dry milling treatment of [FeCl 2 {κ 3 -HC(pz) 3 }] and ferrite (1:1 mass ratio) at room temperature (see Section 3.
doi:10.3390/catal8020069 fatcat:l7oi2ch22jgqdp3u27vppfwbje