caa a22 4500 606173870 CHVBK 20210128100735.0 cr unu---uuuuu 210128e20150501xx s 000 0 eng 10.1007/s11244-015-0385-x doi (NATIONALLICENCE)springer-10.1007/s11244-015-0385-x Patterned Grafted Lewis-Acid Sites on Surfaces: Olefin Epoxidation Catalysis Using Tetrameric Ti(IV)-Calix[4]arene Complexes [Elektronische Daten] [Lena Winner, Gregory Daniloff, Rita Nichiporuk, Andrew Solovyov, Alexander Katz] Tetrameric Ti(IV)-calix[4]arene complexes were synthesized and characterized as well as grafted on a hydroxylated SiO2 inorganic support as an example of patterned Lewis-acid sites on an inorganic oxide surface. These complexes consist of a novel calixareneorganic ligand with varying lengths of tethers to a central aromatic core,and with the calixarene coordinating four titanium(IV)-cations via tetrahedral recognition on the lower rim. Catalysis of these materials was investigated with a probe reaction consisting of the epoxidation 1-octene with tert-butylhydroperoxide as the oxidant, and a comparison of their hydrolytic stability was performed. The oligomeric calix[4]arenes showed similar behavior in catalysis to the monomeric control, with the exception of the material with the shortest tether length, which shows a 1.3-fold higher activity that may be due to a modest cooperativity effect. In hydrolytic leaching tests, the oligomeric complexes showed higher stability compared to the monomeric complex, and this stability appeared to be more thermodynamic rather than kinetic in nature. We hypothesize that encapsulatation of the tetrameric active site within a silica mesopore of the supportcontributes to this stability. Springer Science+Business Media New York, 2015 Terminal olefin epoxidation nationallicence Titanium nationallicence Calixarene nationallicence Organic hydroperoxide nationallicence Catalyst deactivation nationallicence Heterogeneous catalysis nationallicence Winner Lena Department of Chemical and Biomolecular Engineering, University of California at Berkeley, 94720, Berkeley, CA, USA aut Daniloff Gregory Department of Chemical and Biomolecular Engineering, University of California at Berkeley, 94720, Berkeley, CA, USA aut Nichiporuk Rita QB3 Institute, University of California at Berkeley, 94720, Berkeley, CA, USA aut Solovyov Andrew Department of Chemical and Biomolecular Engineering, University of California at Berkeley, 94720, Berkeley, CA, USA aut Katz Alexander Department of Chemical and Biomolecular Engineering, University of California at Berkeley, 94720, Berkeley, CA, USA aut Topics in Catalysis Springer US; http://www.springer-ny.com 58/7-9(2015-05-01), 441-450 1022-5528 58:7-9<441 2015 58 11244 https://doi.org/10.1007/s11244-015-0385-x text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 research-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s11244-015-0385-x text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Winner Lena Department of Chemical and Biomolecular Engineering, University of California at Berkeley, 94720, Berkeley, CA, USA aut NATIONALLICENCE 700 1- Daniloff Gregory Department of Chemical and Biomolecular Engineering, University of California at Berkeley, 94720, Berkeley, CA, USA aut NATIONALLICENCE 700 1- Nichiporuk Rita QB3 Institute, University of California at Berkeley, 94720, Berkeley, CA, USA aut NATIONALLICENCE 700 1- Solovyov Andrew Department of Chemical and Biomolecular Engineering, University of California at Berkeley, 94720, Berkeley, CA, USA aut NATIONALLICENCE 700 1- Katz Alexander Department of Chemical and Biomolecular Engineering, University of California at Berkeley, 94720, Berkeley, CA, USA aut NATIONALLICENCE 773 0- Topics in Catalysis Springer US; http://www.springer-ny.com 58/7-9(2015-05-01), 441-450 1022-5528 58:7-9<441 2015 58 11244