N-Salicylidene)aniline Derived Schiff Base Complexes of Methyltrioxorhenium(VII): Ligand Influence and Catalytic Performance

Met hyltrioxorlienium (VII) (MTO) readily forms 1:1 adducts with several N-(salicylidene)ani line derived Schiff bases. If the aromatic rings of the N-(salicylidene)aniline ligands display non-donating or electron withdrawing substituent groups, the resulting MTO adducts show good activities in olefin epoxidations. However, steric effects seem to play a major role, leading often to instable o- and m-Schiff base-MTO adducts, while p-substituted Schiff bases usually lead to more stable adducts. In catalysis, electron-withdrawing substituents oil the aniline moiety lead to better catalysts than electron donating ones. The gap between good catalysts and instable or non-existing compounds, however, is small. The general tendency, however, that good donors on the Schiff base ligands lead to shorter Re-O(Schiff base) bridges and lower catalytic activity, while the opposite is true with acceptor ligands oil the Schiff bases, seems to be quite clear.     «

Met hyltrioxorlienium (VII) (MTO) readily forms 1:1 adducts with several N-(salicylidene)ani line derived Schiff bases. If the aromatic rings of the N-(salicylidene)aniline ligands display non-donating or electron withdrawing substituent groups, the resulting MTO adducts show good activities in olefin epoxidations. However, steric effects seem to play a major role, leading often to instable o- and m-Schiff base-MTO adducts, while p-substituted Schiff bases usually lead to more stable adducts. In...     »

ISI Document Delivery No.: 418SE Times Cited: 14 Cited Reference Count: 85 Zhou, Ming-Dong Yu, Yang Capape, Alejandro Jain, Kavita R. Herdtweck, Eberhardt Li, Xiao-Rong Li, Jun Zang, Shu-Liang Kuhn, Fritz E. Jain, Kavita/C-9990-2009; Kuhn, Fritz/A-3113-2010 Baverische Forschungstiftung (co-operation between FEK and SLZ, PhD grant for KRJ). the International Graduate School of Science and Engineering This work was generously supported by the Baverische Forschungstiftung (co-operation between FEK and SLZ, PhD grant for KRJ). the International Graduate School of Science and Engineering (IGSSE Ph.D gorant for MDZ), and the Bavarian elite-rietwork NanoCat. FEK is also grateful to the National University of Singapore (NUS) for it visiting professorship, allowing him to spend more time on science than usual. 14 Wiley-v c h verlag gmbh Weinheim     «

ISI Document Delivery No.: 418SE Times Cited: 14 Cited Reference Count: 85 Zhou, Ming-Dong Yu, Yang Capape, Alejandro Jain, Kavita R. Herdtweck, Eberhardt Li, Xiao-Rong Li, Jun Zang, Shu-Liang Kuhn, Fritz E. Jain, Kavita/C-9990-2009; Kuhn, Fritz/A-3113-2010 Baverische Forschungstiftung (co-operation between FEK and SLZ, PhD grant for KRJ). the International Graduate School of Science and Engineering This work was generously supported by the Baverische Forschungstiftung (co-operation between FEK...     »