15869-85-9Relevant articles and documents
Mechanistic studies of ethylene and α-olefin co-oligomerization catalyzed by chromium-PNP complexes
Do, Loi H.,Labinger, Jay A.,Bercaw, John E.
experimental part, p. 5143 - 5149 (2012/09/05)
To explore the possibility of producing a narrow distribution of mid- to long-chain hydrocarbons from ethylene as a chemical feedstock, co-oligomerization of ethylene and linear α-olefins (LAOs) was investigated, using a previously reported chromium complex, [CrCl 3(PNPOMe)] (1, where PNPOMe = N,N-bis(bis(o-methoxyphenyl)phosphino)methylamine). Activation of 1 by treatment with modified methylaluminoxane (MMAO) in the presence of ethylene and 1-hexene afforded mostly C6 and C10 alkene products. The identities of the C10 isomers, assigned by detailed gas chromatographic and mass spectrometric analyses, strongly support a mechanism that involves five- and seven-membered metallacyclic intermediates comprised of ethylene and LAO units. Using 1-heptene as a mechanistic probe, it was established that 1-hexene formation from ethylene is competitive with formation of ethylene/LAO cotrimers and that cotrimers derived from one ethylene and two LAO molecules are also generated. Complex 1/MMAO is also capable of converting 1-hexene to C12 dimers and C18 trimers, albeit with poor efficiency. The mechanistic implications of these studies are discussed and compared to previous reports of olefin cotrimerization.
New zeolite Al-COE-4: Reaching highly shape-selective catalytic performance through interlayer expansion
Yilmaz, Bilge,Müller, Ulrich,Feyen, Mathias,Zhang, Haiyan,Xiao, Feng-Shou,De Baerdemaeker, Trees,Tijsebaert, Bart,Jacobs, Pierre,De Vos, Dirk,Zhang, Weiping,Bao, Xinhe,Imai, Hiroyuki,Tatsumi, Takashi,Gies, Hermann
, p. 11549 - 11551 (2013/01/15)
A ferrierite-type layered aluminosilicate, Al-RUB-36, was prepared for the first time and its interlayer expansion resulted in new zeolite catalysts denoted Al-COE-3 and Al-COE-4. Decane hydroconversion tests demonstrated the highly active and shape-selective nature of the new Al-COE-4 catalyst with an unprecedented isomerization yield, highlighting the potential of this material as a hydroisomerization catalyst. This is the first report on achieving shape-selectivity via interlayer expansion. The Royal Society of Chemistry 2012.
Exploring the void structure and activity of RUB-39 based expanded materials using the hydroconversion of decane
Tijsebaert, Bart,Henry, Mathieu,Gies, Hermann,Xiao, Feng-Shou,Zhang, Weiping,Bao, Xinhe,Imai, Hiroyuki,Tatsumi, Takashi,Mueller, Ulrich,Yilmaz, Bilge,Jacobs, Pierre,Vos, Dirk De
experimental part, p. 47 - 53 (2011/10/13)
The layered silicate RUB-39 can be transformed by topotactic condensation into RUB-41 (RRO), a zeolite with 8- and 10- ring pores. If the layered RUB-39 is first silylated with dichlorodimethylsilane (DCDMS) or hexamethyldisiloxane (HMDS), an interlayer expanded structure is created after calcination. The DCDMS expanded material contains 10- and 12-ring pores instead of 8- and 10-ring pores. Detailed physicochemical characterization showed that the Al content is not significantly changed during the expansion. In the hydroconversion of decane, the expanded materials have a significantly increased activity, as demonstrated by the lower temperatures at which isomerization and cracking occur. Detailed comparison of the product selectivities obtained with RUB-41 or with its expanded analogs shows that the void structure of the expanded materials is significantly less constrained, as reflected in the distribution of methylnonane isomers, of the ethyloctane vs. methylnonane isomers, and in the ratio of monobranched vs. dibranched isomers.
