{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,6,13]],"date-time":"2026-06-13T12:23:32Z","timestamp":1781353412486,"version":"3.54.1"},"reference-count":75,"publisher":"Wiley","issue":"30","license":[{"start":{"date-parts":[[2013,6,18]],"date-time":"2013-06-18T00:00:00Z","timestamp":1371513600000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/onlinelibrary.wiley.com\/termsAndConditions#vor"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Chemistry A European J"],"published-print":{"date-parts":[[2013,7,22]]},"abstract":"<jats:title>Abstract<\/jats:title><jats:p>TiCl<jats:sub>4<\/jats:sub> grafted to dehydrated silica is an industrially applied catalyst for the epoxidation of propylene. As with many heterogeneous catalysts, the precise nature of the surface species is not yet fully known, prohibiting reliable structure\u2013activity correlations. In this study, the speciation and restructuring of site\u2010isolated Ti<jats:sup>IV<\/jats:sup> Lewis acid centers was carefully investigated by using a variety of techniques. The initially formed \uf8fdSiOTiCl<jats:sub>3<\/jats:sub> species were found to restructure upon heating through the transfer of Cl ligands to the silica surface, eventually leading to tripodal (\uf8fdSiO)<jats:sub>3<\/jats:sub>TiCl species. The superior activity and stability of such tripodal species is demonstrated for catalytic olefin epoxidation under continuous flow conditions.<\/jats:p>","DOI":"10.1002\/chem.201300842","type":"journal-article","created":{"date-parts":[[2013,6,18]],"date-time":"2013-06-18T14:09:17Z","timestamp":1371564557000},"page":"9849-9858","source":"Crossref","is-referenced-by-count":27,"title":["Thermal Restructuring of Silica\u2010Grafted TiCl<sub><i>x<\/i><\/sub> Species and Consequences for Epoxidation Catalysis"],"prefix":"10.1002","volume":"19","author":[{"given":"Philipp","family":"Mania","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ren\u00e9","family":"Verel","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Florian","family":"Jenny","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ceri","family":"Hammond","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ive","family":"Hermans","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"311","published-online":{"date-parts":[[2013,6,18]]},"reference":[{"key":"e_1_2_6_1_2","unstructured":"\u00a0"},{"key":"e_1_2_6_2_2","doi-asserted-by":"publisher","DOI":"10.1002\/ange.200462473"},{"key":"e_1_2_6_2_3","doi-asserted-by":"publisher","DOI":"10.1002\/anie.200462473"},{"key":"e_1_2_6_3_2","doi-asserted-by":"publisher","DOI":"10.1021\/cr030680z"},{"key":"e_1_2_6_4_2","volume-title":"Metal\u2010Catalyzed Oxidations of Organic Compounds","author":"Sheldon R. A.","year":"1981"},{"key":"e_1_2_6_5_2","doi-asserted-by":"publisher","DOI":"10.1002\/cssc.200900020"},{"key":"e_1_2_6_6_2","doi-asserted-by":"publisher","DOI":"10.1016\/B978-0-444-53188-9.00013-4"},{"key":"e_1_2_6_7_2","doi-asserted-by":"publisher","DOI":"10.1016\/j.cattod.2004.06.041"},{"key":"e_1_2_6_8_2","unstructured":"\u00a0"},{"key":"e_1_2_6_9_2","doi-asserted-by":"publisher","DOI":"10.1021\/ie0513090"},{"key":"e_1_2_6_10_2","doi-asserted-by":"publisher","DOI":"10.1021\/cs200017s"},{"key":"e_1_2_6_11_2","doi-asserted-by":"publisher","DOI":"10.1021\/la900578u"},{"key":"e_1_2_6_12_2","doi-asserted-by":"publisher","DOI":"10.1021\/jp074512c"},{"key":"e_1_2_6_13_2","doi-asserted-by":"publisher","DOI":"10.1016\/S1381-1169(03)00215-2"},{"key":"e_1_2_6_14_2","doi-asserted-by":"publisher","DOI":"10.1021\/ja0202208"},{"key":"e_1_2_6_15_2","doi-asserted-by":"publisher","DOI":"10.1021\/ja9829160"},{"key":"e_1_2_6_16_2","doi-asserted-by":"publisher","DOI":"10.1021\/la00073a020"},{"key":"e_1_2_6_17_2","doi-asserted-by":"publisher","DOI":"10.1021\/jp902200c"},{"key":"e_1_2_6_18_2","doi-asserted-by":"publisher","DOI":"10.1021\/cr9903508"},{"key":"e_1_2_6_19_2","doi-asserted-by":"publisher","DOI":"10.1039\/a901016e"},{"key":"e_1_2_6_20_2","doi-asserted-by":"publisher","DOI":"10.1021\/la00036a026"},{"key":"e_1_2_6_21_2","doi-asserted-by":"publisher","DOI":"10.1016\/0040-6090(93)90170-T"},{"key":"e_1_2_6_22_2","doi-asserted-by":"publisher","DOI":"10.1021\/cs200411d"},{"key":"e_1_2_6_23_2","first-page":"287","volume-title":"Infrared Studies of Chemically Modified Silica","author":"Morrow B. A.","year":"2005"},{"key":"e_1_2_6_24_2","unstructured":"\u00a0"},{"key":"e_1_2_6_25_2","doi-asserted-by":"publisher","DOI":"10.1039\/c1sc00073j"},{"key":"e_1_2_6_26_2","doi-asserted-by":"publisher","DOI":"10.1039\/c1nj20506d"},{"key":"e_1_2_6_27_2","unstructured":"\u00a0"},{"key":"e_1_2_6_28_2","doi-asserted-by":"publisher","DOI":"10.1002\/ange.200390040"},{"key":"e_1_2_6_28_3","doi-asserted-by":"publisher","DOI":"10.1002\/anie.200390072"},{"key":"e_1_2_6_29_2","doi-asserted-by":"publisher","DOI":"10.1016\/j.ccr.2007.06.008"},{"key":"e_1_2_6_30_2","doi-asserted-by":"publisher","DOI":"10.1007\/s11244-008-9049-4"},{"key":"e_1_2_6_31_2","doi-asserted-by":"publisher","DOI":"10.1021\/ar2001342"},{"key":"e_1_2_6_32_2","unstructured":"\u00a0"},{"key":"e_1_2_6_33_2","doi-asserted-by":"publisher","DOI":"10.1016\/S0927-7757(00)00556-2"},{"key":"e_1_2_6_34_2","doi-asserted-by":"publisher","DOI":"10.1021\/jp206301c"},{"key":"e_1_2_6_35_2","unstructured":"\u00a0"},{"key":"e_1_2_6_36_2","doi-asserted-by":"publisher","DOI":"10.1021\/cs2003774"},{"key":"e_1_2_6_37_2","doi-asserted-by":"publisher","DOI":"10.1039\/b603426h"},{"key":"e_1_2_6_38_2","doi-asserted-by":"publisher","DOI":"10.1021\/j100121a040"},{"key":"e_1_2_6_39_2","unstructured":"Excess of physisorbed TiCl4can be excluded based on the observed hydroxyl site stoichiometry and the Cl\/Ti ratio being lower than four as well as the UV\/Vis spectra reported in Figure\u20055."},{"key":"e_1_2_6_40_2","unstructured":"The IR spectrum in Figure\u20052 shows that a very small amount of \uf8fdSiOH groups did not react with TiCl4 most likely because they are not accessible. It can however not be excluded that TiCl4catalyzes the migration of those inaccessible \uf8fdSiOHs through migration of siloxane bridges and ultimately leads to HCl and H2O."},{"key":"e_1_2_6_41_2","doi-asserted-by":"publisher","DOI":"10.1021\/ja108905p"},{"key":"e_1_2_6_42_2","doi-asserted-by":"publisher","DOI":"10.1021\/ja3008566"},{"key":"e_1_2_6_43_2","unstructured":"\u00a0"},{"key":"e_1_2_6_44_2","doi-asserted-by":"publisher","DOI":"10.1021\/jp074219c"},{"key":"e_1_2_6_45_2","doi-asserted-by":"publisher","DOI":"10.1016\/S0920-5861(99)00048-6"},{"key":"e_1_2_6_46_2","doi-asserted-by":"publisher","DOI":"10.1021\/jp981423e"},{"key":"e_1_2_6_47_2","doi-asserted-by":"publisher","DOI":"10.1016\/j.cplett.2008.08.095"},{"key":"e_1_2_6_48_2","doi-asserted-by":"publisher","DOI":"10.1021\/ja802486q"},{"key":"e_1_2_6_49_2","unstructured":"The sharp and intense peak at 49\u2005MHz in the sample post\u2010treated at 450\u2009\u00b0C is an experimental artifact and should be neglected."},{"key":"e_1_2_6_50_2","doi-asserted-by":"publisher","DOI":"10.1139\/v07-069"},{"key":"e_1_2_6_51_2","unstructured":"\u00a0"},{"key":"e_1_2_6_52_2","doi-asserted-by":"publisher","DOI":"10.1021\/j100559a010"},{"key":"e_1_2_6_53_2","doi-asserted-by":"publisher","DOI":"10.1016\/0039-6028(89)90337-3"},{"key":"e_1_2_6_54_2","unstructured":"After purification the (TMS)2NCH3probe molecule contains 10\u201350\u2005ppm water which leads to some in situ HCl formation through the hydrolysis of Ti\uf8ffCl bonds."},{"key":"e_1_2_6_55_2","unstructured":"\u00a0"},{"key":"e_1_2_6_56_2","doi-asserted-by":"publisher","DOI":"10.1021\/jp961487u"},{"key":"e_1_2_6_57_2","first-page":"9825","volume":"38","author":"Stern E. A.","year":"1993","journal-title":"Bull. Am. Phys. Soc."},{"key":"e_1_2_6_58_2","unstructured":"The region around 3.5\u2005\u00c5 could be fitted with Si as a scatterer but not with Ti as scatterer as already reported by Fraile et\u2005al. in ref.\u2005[25\u2009a]."},{"key":"e_1_2_6_59_2","unstructured":"\u00a0"},{"key":"e_1_2_6_60_2","doi-asserted-by":"publisher","DOI":"10.1021\/jp7119153"},{"key":"e_1_2_6_61_2","doi-asserted-by":"publisher","DOI":"10.1016\/j.jcat.2008.11.024"},{"key":"e_1_2_6_62_2","doi-asserted-by":"publisher","DOI":"10.1016\/j.apsusc.2009.09.062"},{"key":"e_1_2_6_63_2","doi-asserted-by":"publisher","DOI":"10.1063\/1.356160"},{"key":"e_1_2_6_64_2","doi-asserted-by":"publisher","DOI":"10.1021\/cs200354c"},{"key":"e_1_2_6_65_2","unstructured":"Gaussian\u200509 Revision A. 02 M.\u2005J. Frisch G.\u2005W. Trucks H.\u2005B. Schlegel G.\u2005E. Scuseria M.\u2005A. Robb J.\u2005R. Cheeseman G. Scalmani V. Barone B. Mennucci G.\u2005A. Petersson H. Nakatsuji M. Caricato X. Li H.\u2005P. Hratchian A.\u2005F. Izmaylov J. Bloino G. Zheng J.\u2005L. Sonnenberg M. Hada M. Ehara K. Toyota R. Fukuda J. Hasegawa M. Ishida T. Nakajima Y. Honda O. Kitao H. Nakai T. Vreven J.\u2005A. Montgomery \u2005Jr. J.\u2005E. Peralta F. Ogliaro M. Bearpark J.\u2005J. Heyd E. Brothers K.\u2005N. Kudin V.\u2005N. Staroverov R. Kobayashi J. Normand K. Raghavachari A. Rendell J.\u2005C. Burant S.\u2005S. Iyengar J. Tomasi M. Cossi N. Rega J.\u2005M. Millam M. Klene J.\u2005E. Knox J.\u2005B. Cross V. Bakken C. Adamo J. Jaramillo R. Gomperts R.\u2005E. Stratmann O. Yazyev A.\u2005J. Austin R. Cammi C. Pomelli J.\u2005W. Ochterski R.\u2005L. Martin K. Morokuma V.\u2005G. Zakrzewski G.\u2005A. Voth P. Salvador J.\u2005J. Dannenberg S. Dapprich A.\u2005D. Daniels O. Farkas J.\u2005B. Foresman J.\u2005V. Ortiz J. Cioslowski D.\u2005J. Fox Gaussian Inc. Wallingford CT 2009."},{"key":"e_1_2_6_66_2","unstructured":"\u00a0"},{"key":"e_1_2_6_67_2","doi-asserted-by":"publisher","DOI":"10.1063\/1.462066"},{"key":"e_1_2_6_67_3","doi-asserted-by":"publisher","DOI":"10.1063\/1.463343"},{"key":"e_1_2_6_67_4","doi-asserted-by":"publisher","DOI":"10.1063\/1.464913"},{"key":"e_1_2_6_68_2","doi-asserted-by":"publisher","DOI":"10.1103\/PhysRevB.37.785"},{"key":"e_1_2_6_69_2","doi-asserted-by":"publisher","DOI":"10.1016\/0009-2614(93)80086-5"},{"key":"e_1_2_6_70_2","doi-asserted-by":"publisher","DOI":"10.1021\/jp960976r"},{"key":"e_1_2_6_71_2","doi-asserted-by":"publisher","DOI":"10.1021\/cr9904009"}],"container-title":["Chemistry \u2013 A European Journal"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/api.wiley.com\/onlinelibrary\/tdm\/v1\/articles\/10.1002%2Fchem.201300842","content-type":"unspecified","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/chemistry-europe.onlinelibrary.wiley.com\/doi\/pdf\/10.1002\/chem.201300842","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,12]],"date-time":"2025-10-12T17:19:00Z","timestamp":1760289540000},"score":1,"resource":{"primary":{"URL":"https:\/\/chemistry-europe.onlinelibrary.wiley.com\/doi\/10.1002\/chem.201300842"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2013,6,18]]},"references-count":75,"journal-issue":{"issue":"30","published-print":{"date-parts":[[2013,7,22]]}},"alternative-id":["10.1002\/chem.201300842"],"URL":"https:\/\/doi.org\/10.1002\/chem.201300842","archive":["Portico"],"relation":{},"ISSN":["0947-6539","1521-3765"],"issn-type":[{"value":"0947-6539","type":"print"},{"value":"1521-3765","type":"electronic"}],"subject":[],"published":{"date-parts":[[2013,6,18]]}}}