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NMR and EPR Spectroscopy in the Study of the Mechanisms of Metallocene and Post-Metallocene Polymerization and Oligomerization of α-Olefins
Published in Evgenii Talsi, Konstantin Bryliakov, Applications of EPR and NMR Spectroscopy in Homogeneous Catalysis, 2017
Evgenii Talsi, Konstantin Bryliakov
1-Hexene is industrially used as comonomer in the production of linear low-density polyethylene (LLDPE). In industry, 1-hexene is usually obtained by nonselective (statistical) oligomerization of ethylene [177]. The only commercial process capable of selectively producing 1-hexene utilizes chromium-based catalyst [178]. Catalyst systems capable of selective 1-hexene production would be of great industrial and academic interest (see the review by McGuinness [179]). Apart from chromium-based trimerization catalysts, systems relying on titanium complexes have attracted significant interest. Hessen and coworkers discovered a highly active and selective titanium-based catalyst system for this transformation [180]. One of the major recent developments has been the emergence of complex (FI)TiCl3 (9Ti) (FI = phenoxy imine ligand with additional O-donor, Figure 4.56). When activated with MAO, 9Ti produced 1-hexene with exceptionally high activity (up to 132 kg of 1-hexene [g of Ti]−1 h−1 bar−1) [181].
Schiff base complexes of Mo(VI) immobilized on functionalized graphene oxide nano-sheets for the catalytic epoxidation of alkenes
Published in Journal of Coordination Chemistry, 2019
Behnam Rezazadeh, Ali Reza Pourali, Alireza Banaei, Hossein Behniafar
These new catalysts, MoO2L1-GO, MoO2L2-GO and MoO2L3-GO, can be used for the epoxidation of a wide range of substituted alkenes (Table 2). Based on the epoxidation mechanism suggested earlier [30], higher electron donating ability of olefin double bond is anticipated to show more epoxidation reactivity. Therefore, cyclohexene and cyclooctene with inner double bonds should exhibit more activity in comparison to 1-hexene and 1-octene which contain terminal double bonds. Among the endocyclic olefins, cyclooctene was the most reactive (Table 2, entry 2). This reactivity arises from the stability of cyclooctene as well as the high reactivity of its double bond [31]. Steric hindrance on the C = C bond decreased the conversion of the olefins such as 1-methoxy-2-methylprop-1-ene (Table 2, entry 5) and 3,3-dimethylhex-1-ene (Table 2, entry 6) and increased reaction time.
Drag reduction assessment of some new copolymers of 1-hexene and maleic anhydride in light crude oil
Published in Petroleum Science and Technology, 2021
Mahir A. Jalal, Moayad N. Khalaf, Mouayed A. Hussein
Poly(1-hexene-co-diundecyl maleate), poly(1-hexene-co-ditetradecyl maleate), poly(1-hexene-co-dihexadecyl maleate), poly(1-hexene-co-dioctadecyl maleate), poly(1-hexene-co-diicoscyl maleate), and poly(1-hexene-co-didocoscyl maleate), were used as DRA and labeled as B1, B2, B3, B4, B5, and B6, respectively. For detailed information on copolymers synthesis and characterization, see the supplementary data. All those DRAs were compared with DRA-FLO FUSION 3000, as shown in Figure S1, supplied by Baker Hughes company. The Iraqi crude oil was supplied by the Zubair field operation division company (ZFOD). Specifications of Iraqi light crude oil used in the present work are given in Table 1.
Synthesis and characterization of naphthaldiimine-based ruthenium(III) complexes; homogenous catalytic hydrogenation and isomerization of internal and terminal alkenes
Published in Journal of Coordination Chemistry, 2022
Ahmed M. Fathy, Mahmoud M. Hessien, Mohamed M. Ibrahim, Abd El-Motaleb M. Ramadan
Hydrogenation and isomerization processes in a single-vessel catalytic reaction has generated great interest in academia and industry [60]. The present catalysts were employed in the catalytic hydrogenation and isomerization processes of 1-hexene. The catalytic hydrogenation experiments were performed in a similar manner to cyclohexene. The data in Table 15 indicate that Ru(III) complexes under study catalyzed the hydrogenation of 1-hexene without significant difference in activity, as in the case of cyclohexene hydrogenation. The difference from the case of cyclohexene is that the catalytic hydrogenation of 1-hexene led to several products while a single product, cyclohexane, was observed for cyclohexene.