Epoxidation of olefins with H2O2 catalyzed by new symmetrical acetylacetone-based Schiff bases/Mn(II) homogeneous systems: A catalytic and EPR study
Φόρτωση...
Ημερομηνία
Συγγραφείς
Stamatis, A.
Doutsi, P.
Vartzouma, C.
Christoforidis, K. C.
Deligiannakis, Y.
Louloudi, M.
Τίτλος Εφημερίδας
Περιοδικό ISSN
Τίτλος τόμου
Εκδότης
Elsevier
Περίληψη
Τύπος
Είδος δημοσίευσης σε συνέδριο
Είδος περιοδικού
peer reviewed
Είδος εκπαιδευτικού υλικού
Όνομα συνεδρίου
Όνομα περιοδικού
Journal of Molecular Catalysis a-Chemical
Όνομα βιβλίου
Σειρά βιβλίου
Έκδοση βιβλίου
Συμπληρωματικός/δευτερεύων τίτλος
Περιγραφή
Two new symmetrical acetylacetone-based Schiff bases, herein called L-A and L-B have been synthesized. The complexes formed by their association with Mn(II) have been evaluated for catalytic alkene epoxidation with H2O2. The catalytic efficiency of Mn(II)/L-A and Mn(II)/L-B systems were shown to be switched on by ammonium acetate with remarkable effectiveness and selectivity towards epoxides. EPR spectroscopy for Mn(II)/L-A shows that the catalytic centre is a mononuclear Mn complex. Additives that allow easier oxidation of Mn(II) to higher oxidation states, i.e. such as acetate and bicarbonate, can promote decisively the catalytic function. Additives that do not allow oxidation of Mn(II) to higher oxidation states, i.e. such as formate and oxalate, inhibit severely the catalytic function. Monocarboxylate ions, i.e. acetate, bicarbonate and formate do not disturb considerably the first coordination sphere of Mn(II). Dicarboxylate additives, i.e. such as oxalate, form strong complex with the Mn(II). Based on the catalytic and EPR data, a double role is suggested for ammonium acetate. This is to promote Mn(II) oxidation, and to function as a dual acid-base system, participating into the catalytic cycle. (C) 2008 Elsevier B.V. All rights reserved.
Περιγραφή
Λέξεις-κλειδιά
catalytic epoxidation, manganese complexes, hydrogen peroxide activation, additive, epr, field splitting parameter, hydrogen-peroxide, unfunctionalized olefins, asymmetric epoxidation, cis-dihydroxylation, alkene epoxidation, enantioselective epoxidation, manganese catalysts, oxidation reactions, complexes
Θεματική κατηγορία
Παραπομπή
Σύνδεσμος
<Go to ISI>://000262743800006
http://ac.els-cdn.com/S1381116908003944/1-s2.0-S1381116908003944-main.pdf?_tid=f3b9bf76-362e-11e3-83a5-00000aab0f27&acdnat=1381906283_55e9ec17e4d95cd7e2ca9c571dd47ef3
http://ac.els-cdn.com/S1381116908003944/1-s2.0-S1381116908003944-main.pdf?_tid=f3b9bf76-362e-11e3-83a5-00000aab0f27&acdnat=1381906283_55e9ec17e4d95cd7e2ca9c571dd47ef3
Γλώσσα
en
Εκδίδον τμήμα/τομέας
Όνομα επιβλέποντος
Εξεταστική επιτροπή
Γενική Περιγραφή / Σχόλια
Ίδρυμα και Σχολή/Τμήμα του υποβάλλοντος
Πανεπιστήμιο Ιωαννίνων. Σχολή Θετικών Επιστημών. Τμήμα Χημείας