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An approach towards incorporating varied degrees of steric profiles around the ligand's backbone, which were envisaged to alter the catalytic paths leading to targeted 1-C8/1-C6 olefin products, were explored. Cr-pre-catalysts designed with PNP ligands comprising a fused aryl moiety were delivered at a relatively higher C8 olefin selectivity (up to 74.6 wt% and C8/C6 of 3.4) when the N-connection to the aromatic unit was placed at the 2-position. A relatively higher C6 olefin selectivity (up to 33.7 wt% and C8/C6 of 1.9) was achieved with the PNP unit anchored at the 1- or 6-position. Based on detailed catalytic studies, we confirm the fact that by introducing a controlled degree of bulkiness on the N-site through a judicious selection of the N-aryl moiety of different sizes, the selectivity of the targeted olefin product could be tuned in a rational manner. [ABSTRACT FROM AUTHOR]

Application of molecular electron density theory (MEDT) to investigate the [5+2] cycloaddition reaction between oxidopyrylium and ethervinylether, we discovered that oxidopyrylium is an electrophile and ethervinylether is a nucleophile by an examination of conceptual DFT indices. Analysis of energetical parameters shows clearly that this cycloaddition is both regio- and stereoselective, which is extremely consistent with the experience. Topological analysis of the electron localization function (ELF) has shown that this [5+2] cycloaddition is achieved by a two-step, single-step mechanism along the most favored route. Aside from that, docking outcomes show that the (1–20) oxabicyclo[3.2.1]octene derivatives have a significant anti-HIV potential. [ABSTRACT FROM AUTHOR]

The shape memory (SM) polymers with superior SM properties were successfully fabricated based on melt blending of natural rubber (NR) and ethylene octene copolymer (EOC) at various crystallinity of EOC phase. The differential scanning calorimetry analysis, mechanical properties, temperature scanning stress relaxation, and shape memory properties were studied. Results revealed that the mechanical and thermal properties of the prepared NR/EOC blends improved as a function of amount of ethylene fraction in the EOC phase. The ethylene segment of EOC in the NR/EOC blend is triggered as a stimulus-sensitive domain. The shape memory properties in terms of shape fixity and shape recovery efficiencies of the blends tended to increase with the increasing of crystalline segments in the blends. The shape memory properties of the prepared blends substantially exceed the best performance (close to 100%) by blending the NR/EOC at 50/50 parts by weight, having 62%–80% of ethylene content in the EOC phase, which corresponds to approximately 3°–16° of crystallinity of EOC phase in the blends. [ABSTRACT FROM AUTHOR]

Blending octene random copolymer (ORC) with other polymers is a promising approach to improving ORC mechanical properties, such as tensile strength and elongation. In this study, octene block copolymer (OBC) with lower density than ORC and high-density polyethylene (HDPE) were used to blend with ORC. The effect of both OBC and HDPE on ORC was analyzed using scanning electron microscopy (SEM), differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA) and small-angle X-ray scattering (SAXS). For ORC/OBC blends, a small amount of OBC can improve the crystallization ability of ORC. Meanwhile, for ORC/HDPE blends, the crystallization ability of ORC was significantly suppressed, attributed to good compatibility between ORC and HDPE as indicated by the homogeneous morphology and the disappearance of the α transition peak of ORC in ORC/HDPE blends. Therefore, the tensile strength and elongation of ORC/HDPE blends are significantly higher than those of ORC/OBC blends. For ORC/OBC/HDPE ternary blends, we found that when ORC:OBC:HDPE are at a ratio of 70:15:15, cocrystallization is achieved. Although HDPE improves the compatibility of ORC and OBC, the three-phase structure of the ternary blends can be observed through SAXS when HDPE and OBC exceed 30 wt%. Blending HDPE and OBC (≤30 wt%) could improve the mechanical property of ORC. [ABSTRACT FROM AUTHOR]

A short and efficient synthetic access to functionalized compounds displaying major structural elements of the natural product populusone is elaborated by exploiting a diastereoselective Mukaiyama aldol addition followed by a triflic anhydride-induced oxa-Michael addition to construct the sensitive 2-oxa-bicyclo[2.2.2]octene unit as an enol triflate, which is directly used in a subsequent Suzuki cross-coupling. While attempts to close the strained 10-membered ring by means of Ru-catalyzed ring-closing metathesis were not successful, the developed synthetic scheme opens a rapid synthetic access to advanced intermediates, which may allow the completion of the total synthesis of populusone in the future. [ABSTRACT FROM AUTHOR]

Irradiation of 1‐(penta‐3,4‐dienoyl)indole derivatives in the presence of an aromatic ketone by a high‐pressure mercury lamp through Pyrex glass gave two types of cyclized products stereoselectively in high combined yields. The major product was a tetracyclic indoline derivative containing anti‐Bredt‐type azabicyclo[4.2.0]octene moiety produced via photo [2+2] cycloaddition between indole and a distal double bond of allene, accompanied by a small amount of proximal [2+2] adduct. Among a range of aromatic ketones screened, 3′,4′‐methylenedioxyacetophenone was found to sensitize the substrate most effectively. [ABSTRACT FROM AUTHOR]

The selective hydrogenation of octyne in a mixed 1‐octyne/1‐octene feed was investigated by employing Pd/Al2O3 and PdAg/Al2O3 catalysts coated with 1‐butyl‐3‐methylimidazolium dicyanamide ([BMIM][DCA]) as SCILLs (Solid Catalysts with an Ionic Liquid Layer). All SCILLs were compared to an organically modified, 1‐ethylimidazole (EIM) coated catalyst to determine if there is a SCILL effect. Results of the catalysis showed that both uncoated catalysts were highly active (100 % 1‐octyne and 1‐octene conversion) in the hydrogenation reactions with dominant selectivity towards octane. No increase of 1‐octene in the reactor outflow (octene gain) was noted. Coating 1Pd/Al2O3 with [BMIM][DCA] at four monolayers (ML) corresponding to a surface loading of 45 wt% still gave 100 % octyne conversion but now with a 54 % 1‐octene gain, as no octene was converted. Coating 1Pd9Ag/Al2O3 with only a single monolayer of [BMIM][DCA] (14 wt%) was sufficient to give a 1‐octene gain of 84 % at an octyne conversion of 91 %. Time‐on‐stream reactions for the uncoated and SCILL systems showed stable operation during the experiments. [ABSTRACT FROM AUTHOR]

• A bottom-up approach has been developed to readily immobilize TEMPO catalytic redox sites on the pore surface of porous aromatic framework. • The porous PAF-TEMPO catalyst with homogeneously dense distributed TEMPO groups facilitates high efficiency of the electrocatalysis. • The established catalytic system can deliver water-based oxidation to avoid the use of toxic oxidants or additives for green chemical processes. • The electrocatalysis can achieve oxidation of cyclooctene to valuable epoxycyclooctene in 89.7 % yield and 90.3 % selectivity. The development of economically viable and environmentally benign oxidation reaction systems with high selectivity and efficiency is a key focus in synthetic chemistry. Utilizing water as an oxygen source, alongside an anodic system for converting water to oxygenated compounds, represents an atom-economical and sustainable strategy for highly selectively synthesizing epoxides. Herein, we synthesized a novel porous aromatic framework with TEMPO radicals uniformly immobilized on the pore surface by a synthetic bottom-up approach (PAF-TEMPO). Strategically grafting TEMPO catalytic sites, which results in a highly dense and uniform dispersion, promotes extensive reactant contact, thereby enhancing catalytic efficiency. The PAF-TEMPO catalyst demonstrated efficient electrocatalytic activity for cyclooctene oxidation to cyclooctene oxide, achieving 89.7 % yield and 90.3 % selectivity with good recyclability. This work will give inspiration for novel electrocatalyst design and development of green and sustainable catalytic systems. A TEMPO-functionalized porous aromatic framework has been readily synthesized as electrocatalyst for oxidation of cyclooctene to cyclooctene oxide, achieving 89.7 % yield and 90.3 % selectivity with good recyclability. [Display omitted] [ABSTRACT FROM AUTHOR]

The role of cyclodextrins in accelerating the reaction rate in biphasic hydroformylation: Cyclodextrins facilitate the transport of the substrate 1-octene from the organic bulk phase to the liquid–liquid interface and simultaneously remove the product nonanal from the interfacial region. [Display omitted] • Water based biphasic hydroformylation assisted by cyclodextrins. • Examined for the first time using an in-situ image-based boroscopic technology. • RAME-β cyclodextrins increased the a LL by 84 % • Kinetic study showed that RAME-β cyclodextrins reduce the rate limiting effect of the nonanal concentration. • Increasing RAME-β cyclodextrins concentration decrease dependency of the reaction rates on the conversion progress. Water based biphasic hydroformylation assisted by cyclodextrins is known for enhanced reaction rates in comparison to the non-assisted biphasic hydroformylation. In this paper, the liquid–liquid interface of the hydroformylation of 1–octene, enhanced by randomly methylated-β cyclodextrins (RAME-β cyclodextrins), was examined for the first time using an in-situ image-based boroscopic technology. This technique enables the observation of the liquid–liquid interfacial area (a LL) during the reaction and under reaction conditions, facilitating an explicit analysis of the droplet population. In this study defined mixtures of the reaction components with RAME-β cyclodextrins increased the a LL by 84 %. A kinetic study showed that RAME-β cyclodextrins reduce the rate limiting effect of the nonanal concentration in the two phasic water/octene system on the interphase. The kinetic expression shows consequently higher reaction rates for this three-phase conversion, leading to a 387 % increase in aldehyde yield. When comparing four different amounts of RAME-β cyclodextrins (n CD :n Rh(acac)(CO)2 = 0 / 12:1 / 24:1 / 50:1), we observed a decreasing dependency of the reaction rates on the conversion progress and therefore on the nonanal formation for higher cyclodextrin concentrations. A recovery test of the aqueous phase involving nonanal and 1-octene reveals a drastically increased concentration of 1029 % 1-octene (c octene = 1.08 10-3 mg mg−1) and 13676 % nonanal (c nonanal = 14.41 10–3 mg mg−1) after the addition of 0.002 mol RAME–β cyclodextrins. These findings affirm that RAME-β cyclodextrins primarily remove nonanal from the interfacial region while facilitating an increased availability of 1-octene for the surface bound reaction. [ABSTRACT FROM AUTHOR]

The role of cyclodextrins in accelerating the reaction rate in biphasic hydroformylation: Cyclodextrins facilitate the transport of the substrate 1-octene from the organic bulk phase to the liquid–liquid interface and simultaneously remove the product nonanal from the interfacial region. [Display omitted] • Water based biphasic hydroformylation assisted by cyclodextrins. • Examined for the first time using an in-situ image-based boroscopic technology. • RAME-β cyclodextrins increased the a LL by 84 % • Kinetic study showed that RAME-β cyclodextrins reduce the rate limiting effect of the nonanal concentration. • Increasing RAME-β cyclodextrins concentration decrease dependency of the reaction rates on the conversion progress. Water based biphasic hydroformylation assisted by cyclodextrins is known for enhanced reaction rates in comparison to the non-assisted biphasic hydroformylation. In this paper, the liquid–liquid interface of the hydroformylation of 1–octene, enhanced by randomly methylated-β cyclodextrins (RAME-β cyclodextrins), was examined for the first time using an in-situ image-based boroscopic technology. This technique enables the observation of the liquid–liquid interfacial area (a LL) during the reaction and under reaction conditions, facilitating an explicit analysis of the droplet population. In this study defined mixtures of the reaction components with RAME-β cyclodextrins increased the a LL by 84 %. A kinetic study showed that RAME-β cyclodextrins reduce the rate limiting effect of the nonanal concentration in the two phasic water/octene system on the interphase. The kinetic expression shows consequently higher reaction rates for this three-phase conversion, leading to a 387 % increase in aldehyde yield. When comparing four different amounts of RAME-β cyclodextrins (n CD :n Rh(acac)(CO)2 = 0 / 12:1 / 24:1 / 50:1), we observed a decreasing dependency of the reaction rates on the conversion progress and therefore on the nonanal formation for higher cyclodextrin concentrations. A recovery test of the aqueous phase involving nonanal and 1-octene reveals a drastically increased concentration of 1029 % 1-octene (c octene = 1.08 10-3 mg mg−1) and 13676 % nonanal (c nonanal = 14.41 10–3 mg mg−1) after the addition of 0.002 mol RAME–β cyclodextrins. These findings affirm that RAME-β cyclodextrins primarily remove nonanal from the interfacial region while facilitating an increased availability of 1-octene for the surface bound reaction. [ABSTRACT FROM AUTHOR]

The effect of particle size as well as of coke formation on conversion of intermediate chain length paraffins (C6–C9) to the corresponding olefins was investigated on a promoted Pt catalyst with the model substance n‐octane. Increasing the particle size leads to pore diffusion limitations and thus to a reduction of the activity for paraffin conversion and of the octene selectivity caused by more pronounced formation of consecutive products (aromatics, octadienes). Both effects are adequately predicted by the developed kinetic model. The activity of dehydrogenation declines with the content of coke, but to a lesser extent than the rate of coke formation, which is beneficial regarding the catalyst lifetime. The initial activity is fully recovered by mild coke burn‐off (T < 470 °C). [ABSTRACT FROM AUTHOR]

Philippe de Clermont (1831–1921) was a French organic chemist, known particularly for his synthesis of tetraethyl pyrophosphate, the first organophosphate cholinesterase inhibitor. This achievement was part of an extensive research about phosphoric ethers using Wurtz’s procedure. This type of synthesis was found to be also appropriate for the preparation of carbonic ethers. Another important consequence was that the reaction between ammonia and an ether composed of a mineral oxacid resulted in the formation of an alcoholic alkali. Clermont also carried extensive research about octene and its derivatives that culminated in the synthesis of a large number of new derivatives, among them octylene oxide acetate, caprylene halides and alcohol, octyl glycol, octyl glycol chlorhydrin, etc. Clermont determined the composition of persulfonic acid, synthesized sulfophenylurea, and a variety of thioureas. He also studied a variety of reactions of pyruvic acid, the composition of pyrogallic acid, synthesized purpurogallin, and a variety of metallic sulfides, in particularly the flesh and green sulfides of manganese and the decomposition reaction of ammonium chloride with metallic sulfides. Likewise, he showed that the production of aurin required the presence of nascent CO2. [ABSTRACT FROM AUTHOR]

This study was designed to investigate the effect of molar ratio of 1-octene and type as well as concentration of Lewis acids on the free radical copolymerization of butyl methacrylate (BMA) with 1-octene. The synthesized copolymers have been substantially described by FTIR, 1H NMR, GPC and DSC. The quantitative 1H NMR and GPC demonstrated that by increase in the molar ratio of 1-octene and Lewis acids to BMA, the incorporation of 1-octene in the copolymer backbone enhanced, Mn reduced and polydispersity became narrower. The maximum incorporation of 1-octene (13.7%) was observed for sample CSC7 having [1-octene/BMA] of 3 mol% and [AlCl3/BMA] of 1.5 mol%. The DSC results confirmed the NMR and GPC outcomes, suggesting a decrease in Tg by increasing 1-octene in the copolymer backbone. Moreover, it is found that temperature has a remarkable influence on the copolymerization behavior. The results also showed that by substituting the acrylate monomer from butyl methacrylate to butyl acrylate, the incorporation of 1-octene increased. [ABSTRACT FROM AUTHOR]

The emergence of SARS-CoV-2, responsible for the global COVID-19 pandemic, requires the rapid development of novel antiviral drugs that would contribute to an effective treatment alongside vaccines. Drug repurposing and development of new molecules targeting numerous viral targets have already led to promising drug candidates. To this end, versatile molecular scaffolds with high functionalization capabilities play a key role. Starting with the clinically used conformationally flexible HIV-1 protease inhibitors that inhibit replication of SARS-CoV-2 and bind major protease 3CLpro, we designed and synthesized a series of rigid bicyclo[2.2.2]octenes fused to N-substituted succinimides to test whether this core scaffold could support the development of non-covalent 3CLpro inhibitors. Inhibition assays confirmed that some compounds can inhibit the SARS-CoV-2 main protease; the most promising compound 11a inhibited 3CLpro in micromolar range (IC50 = 102.2 μM). Molecular simulations of the target-ligand complex in conjunction with dynophore analyses and endpoint free energy calculations provide additional insight and first recommendations for future optimization. The fused bicyclo[2.2.2]octenes can be used as a new potential starting point in the development of non-covalent SARS-CoV-2 3CLpro protease inhibitors and the study also substantiates the potential of this versatile scaffold for the development of biologically active molecules. [ABSTRACT FROM AUTHOR]

[Display omitted] • A micro-kinetic model was constructed for the ethylene oligomerization. • Hexene is formed via a series of ethylene coordination-insertion steps. • Octene is formed via co-oligomerization of ethylene and desorbed butene. We report the kinetics of ethylene oligomerization over the Ni-H-Beta for temperatures ranging between 50 and 100 °C and pressures ranging between 5 and 28 atm. According to our results, the apparent activation energies involved in the formation of butene, hexene, and octene are 44, 78, and 60 kJ.mol−1, respectively. The measured lower apparent activation energy for butene formation relative to hexene and octene is a likely result of the fact that the measured butene formation is not the true (forward) rate of formation of butene but it the net rate because of the consumption of butene in secondary reactions. Analysis of the reaction order indicates that participation of butene in chain-growth reactions takes place via desorption followed by re-adsorption of butene on the catalyst. The results also indicate that hexene undergoes a similar process. In the present paper, we refer to the pathway involving co-oligomerization of butene and hexene as "cascade co-oligomerization". Based on these findings, we proposed a reaction network and modeled reaction rate expressions for ethylene consumption and butene, hexene, and octene formation based on the construction of a micro-kinetic model. We calculated the kinetic parameters involved in the reaction network proposed and found evidence that the formation of octene proceeds mainly via the "cascade co-oligomerization" of re-adsorbed butene with ethylene. [ABSTRACT FROM AUTHOR]

Efficient and reliable synthesis of substituted hydrazinylpyridines in thick-wall ACE tubes via nucleophilic substitution of a chlorine substituent in different chloropyridines is presented. Hydrazine hydrate and alkylhydrazines were used as nucleophiles and simple alcohols and diethyl ether were the only organic solvents necessary, making the process environmentally and user friendly, potentially reaching 100% atomic efficiency. In the next step, transformations of succinic anhydride moieties fused to the bicyclo[2.2.2]octene framework into succinimide moieties via nucleophilic substitution of oxygens were conducted. As nucleophiles two of the synthesized hydrazinylpyridines (2-hydrazinyl-3-nitropyridine and 2-hydrazinyl-5-nitropyridine) and also hydrazine hydrate, phenylhydrazine, and 4-nitrophenylhydrazine were used. Reactions were again carried out in ACE tubes and only simple alcohols, diethyl ether, and acetone were needed as solvents. One of the prepared bicyclo[2.2.2]octene adducts displayed water solubility thus being a promising candidate for future studies as a novel bidentate ligand for various metal cations in aqueous solutions or acting as an unprecedented halogen bond acceptor. [ABSTRACT FROM AUTHOR]

UTKO1 is a synthetic analog of a natural tumor cell migration inhibitor, moverastin, isolated from microbial extracts of Aspergillus sp. 7720. UTKO1 was initially developed as a mixture of the stereoisomers. In this study, a concise and unified synthesis of the 4 optically active stereoisomers of UTKO1 was achieved from a known optically pure dihydro-α-ionone through a 5-step sequence. The key transformation in the synthesis was a Nozaki–Hiyama–Kishi (NHK) reaction between an optically active enoltriflate and a known aldehyde to install the chiral allylic hydroxy group at C2′. Simple chromatographic separation of the 2 diastereomers with regard to the allylic hydroxy group was possible by the derivatization into the corresponding acetals with Nemoto's optical resolution reagent, (S)- or (R)-5-allyl-2-oxabicyclo[3.3.0]octene (ALBO). All 4 synthetic stereoisomers of UTKO1 exhibited comparable tumor cell migration inhibitory activity. [ABSTRACT FROM AUTHOR]

β-Ketophosphonates, with the keto group linked to a bicyclo[3.3.0]oct(a)ene fragment, were synthesized starting from two diacids. These diacids were first transformed into internal anhydrides and one into a diester. The anhydrides and the diester were reacted with the lithium salt of dimethyl methanephosphonate to give two carboxy β-ketophosphonates, an ester β-ketophosphonate and a bis β-ketophosphonate in good yield. The ester β-ketophosphonate, obtained by two routes was used in the E-HEW selective olefination of a prostaglandin aldehyde with an α-side chain to give the 15-keto prostaglandin analogue in good yield. The compounds were characterized by elemental analysis, IR and high resolution 1H- and 13C-NMR spectroscopies. [ABSTRACT FROM AUTHOR]

Olefin metathesis of α‐olefins (C6, C8, C10), α, β‐unsaturated ester, α, β‐ unsaturated acetate and cross‐metathesis of 1‐octene and ethyl 6‐heptenoate were carried out using well‐defined [(≡Si−O−)W(CH3)5] and [(≡Si−O−)Mo(≡CtBu)(CH2tBu)2] pre‐catalysts. During the reaction, it was observed that irrespective of the chain length, linear α‐olefins are almost showing similar TON. We observed that Mo pre‐catalyst performs better with TONs between 700 and 1478 as compared to W with TONs between 213 and 962 at room temperature. Both pre‐catalysts performed equally at 70 °C, with almost similar activity as well as TON (≈1700). We also carried out self‐metathesis of functionalized olefins using both silica‐supported W and Mo pre‐catalysts. It was observed that W pre‐catalyst performs much better than Mo pre‐catalyst for functionalized olefin metathesis reaction in our conditions. Additionally, we noticed that W pre‐catalyst provides selective metathesis product, whereas Mo pre‐catalyst gives a range of products due to the isomerization of the olefinic bond. [ABSTRACT FROM AUTHOR]

The recycled polypropylene (RPP) and ethylene-octene copolymer (POE) were used as the main raw materials. The RPP/POE blends were prepared by melt blending method. The mechanical properties and thermal properties of RPP/POE blends as well as the effect of compatibilizers on the mechanical properties were studied. The results showed that with the increase of POE addition, the tensile strength and impact strength of RPP/POE blends increased at first and then decreased, elongation at break tended to increase first and then stabilize, but the flexural strength decreased gradually. When the addition of POE was 5%, the tensile strength of the blend reached its maximum 16.7 MPa. When the addition of POE exceeded 20%, the elongation at break reached 400%, the impact strength increased to 5 times of that of RPP, and the flexural decreased to 50% that of RPP. Furthermore, the Vicat softening temperature of the blends decreased with an increase of the POE addition, and the introduction of POE had a little influence on the crystal structure of RPP, but had a baffling effect on the crystallization of RPP. Moreover, compared with PP-g-MAH, compatibilizer POE-g-MAH was more suitable for improving the strength and toughness of RPP/POE blends. [ABSTRACT FROM AUTHOR]

Comparative studies (gel permeation chromatography and evaluation of turbulent drag reduction effectiveness on a turbulence rheometer) of ultra-high molecular weight polymers from a series of higher alpha-olefins (hexene, octene, decene, dodecene) used as hydrodynamic drag agents have been carried out. It was found that the activity of hexene in the polymerization on a titanium magnesium catalyst, if all other relevant factors remain unaltered, significantly exceeds the activity of octene, decene, and dodecene (the conversion of hexene in 24 h is almost 1.5 times higher than the conversion of other monomers over the same time), and the rates of polymerization of the latter differ slightly. The average molecular weights of all polymers differ only slightly: ~6 millions Da for polyhexene and ~5 millions Da for all the others. At the same time, the drag reduction effectiveness of the polymers showed a significant dependence on the nature of the initial monomers: the drag reduction effectiveness rapidly diminishes with an increase in the molecular weight of the corresponding alpha-olefin (3–4 times upon transition from polyhexene to polydodecene). [ABSTRACT FROM AUTHOR]

[Display omitted] • Covalent adaptable networks were made from multi-block ethylene/1-octene copolymers. • OBC CANs are robust and reprocessable from dialkylamino disulfide dynamic chemistry. • Crystallinity in OBCs correlates with cross-link density in CANs and thermosets. • Increasing melt index in OBCs decreases cross-link density in CANs and thermosets. Chain shuttling polymerization has facilitated the rapid development of olefin block copolymers (OBCs) such as ethylene/1-octene multi-block copolymers. The properties of OBCs stem from various parameters such as average block length, number of blocks per chain, etc., which lead to complexity associated with establishing structure–property relationships between precursor OBCs and properties of cross-linked OBCs. Additionally, permanent cross-linking of OBCs sacrifices their recyclability, and cross-linked OBCs capable of being reprocessed have seldom been reported. Here, permanently cross-linked OBCs (OBCXs) and dynamically cross-linked OBCs, or OBC covalent adaptable networks (CANs), were synthesized by melt-state reactive processing of neat OBCs with various crystallinities and melt flow indices (MFIs). The OBC CANs are capable of dialkylamino disulfide dynamic chemistry via the grafting of bis(2,2,6,6-tetramethyl-4-piperidyl methacrylate) disulfide, or BiTEMPS methacrylate, cross-linkers onto OBC backbone chains. Thermomechanical characterizations indicate that increasing crystallinity and decreasing MFI in precursor OBCs lead to higher cross-link densities in OBCXs and OBC CANs. Dynamically cross-linking OBCs into CANs also significantly improves their elevated-temperature creep resistance. Stress relaxation results of OBC CANs indicate an increased average relaxation time with greater cross-link density. Distinct from other CANs capable of dialkylamino disulfide chemistry, the stress relaxation behaviors of OBC CANs of higher cross-link density show evident dependence on their network viscoelasticities. In OBC CANs of lower cross-link density, the dynamic chemistry more strongly governs their stress relaxation behaviors. Finally, the OBC CANs exhibit full cross-link density and thermomechanical property recovery after reprocessing, whereas the OBCXs cannot be reprocessed due to their irreversible cross-links. [ABSTRACT FROM AUTHOR]

Ag/γ-Al2O3 catalysts, containing 5 and 25 wt% Ag, were synthesized by the slurry phase impregnation method. They were tested for the liquid phase continuous flow preferential hydrogenation of octanal in a mixture with octene. The catalysts were characterised by XRD, IR, BET, SEM, TEM and NH3-TPD. These catalysts showed strong preference for octanal hydrogenation, irrespective of reaction temperature or silver loading. A maximum octanal conversion of 90% with selectivity towards octanol of 94% was achieved over 25 wt% Ag/γ-Al2O3 at 180 °C with minimal octene conversion (< 3%). [ABSTRACT FROM AUTHOR]

Commercial metallocene ethylene–octene random copolymer, Resinex PE RXP 1502 (RXP), was grafted with acrylic or crotonic acid in the solution and in the melt to increase the RXP's polarity and adhesion to cellulose-based substrates. Acrylic or crotonic acids were grafted on the RXP macromolecules which were activated with an oxygen–ozone mixture. The formed graft copolymer was tested as additive to a hot melt adhesive (HMA) improving adhesive properties. The most effective procedure was to graft RXP with acrylic acid in the melt, while grafting activated RXP in a toluene solution was less efficient. The melt grafting efficiency is high and varies between 0.77 and 0.97. The RXP polarity after grafting increases significantly, as there is a 15% decrease in the water contact angle and an increase in the surface energy and its polar component by 1.1–1.7 times as compared to the virgin RXP. The heat-fail temperature resistance in peel of RXP grafted with acrylic and/or crotonic acid increased by more than 10°C, while the heat-fail temperatures of adhesive joints in shear tests were similar. The adhesive joint peel strength increased 1.2 times. The cardboard–HMAs based on virgin RXP adhesive joint peel tests exhibit adhesive failure, whereas the cardboard–HMAs containing grafted RXP joints show cohesive failure. [ABSTRACT FROM AUTHOR]

The biphasic catalytic epoxidation of cyclooctene using the ionic liquid (IL) 1,2‐dimethyl‐3‐octyl‐imidazolium perrhenate ([OMMIM]ReO4) as micellar catalyst and H2O2 as oxidant was investigated. Kinetic experiments were carried out in the intrinsic kinetic regime as proved by variation of stirring rate and temperature. Variation of catalyst concentration allowed for determination of the critical micellar concentration (CMC) of the catalytic IL. The effect of substrate concentrations on the reaction rate was also assessed. Based on the experiments, a kinetic model adapted from enzyme catalysis was proposed to account for the micellar reaction environment. The model takes into account the onset of micelle formation at the CMC. The application of the kinetic model illustrated the good agreement with the experimental data. The model will be applied to other micellar epoxidation reactions and for the design of an appropriate reaction setup in the future. Imidazolium perrhenate ionic liquids form micelles in aqueous H2O2 and thus act as micellar catalysts in epoxidation of cyclooctene. Key parameters such as the critical micelle concentration are determined from kinetic experiments in a batch reactor. The kinetic description is based on an adapted enzyme‐kinetic model, taking into account the micellar nature of the active species. [ABSTRACT FROM AUTHOR]

It was shown that the epoxidation of 1-octene by tert-butyl hydroperoxide in the presence of Mo2B is accompanied by the formation of an amorphous oxygen-containing phase on its surface. It was established that this is the phase that catalyzes the reaction and determines its speed and selectivity. [ABSTRACT FROM AUTHOR]

The cracking reactions of 1-octene over H-ZSM-5 zeolite are studied via micro-reactor and off-line spectroscopic techniques for up to 72 h on stream and a temperature range of 473–673 K. 1-Octene is found to react via a two-cycle hydrocarbon pool mechanism, with strong similarities to that reported for methanol-to-hydrocarbons chemistry. This dual-cycle mechanism requires temperatures of 673 K or higher to function with full efficiency, with lower temperatures deactivating portions of the cyclic mechanism, leading to premature deactivation of the catalyst through over-production of coke species. Inelastic neutron scattering is used to study the coke composition, identifying two distinct deactivation mechanisms depending on reaction temperature. The catalyst is also found to slowly progress from an aromatic-heavy to an olefin-heavy product regime even at full efficiency due to progressive blockage of active sites by amorphous carbon-rich coke. Artificial aging of the zeolite, through steam treatment, is found to shift the catalyst lifetime so that it commences at a later stage in this process, resulting in increased light olefin production. The reduced aromatic production also means that deactivation of the catalyst occurs more slowly in steamed catalysts than in fresh ones, after an equivalent time-on-stream. Collectively, these observations connect with the application of ZSM-5 catalysts to facilitate gasoline-to-olefins chemistry in fluidised catalytic cracking unit operations. [Display omitted] • 1-Octene is found to react via a two-cycle hydrocarbon pool mechanism. • The catalyst progresses from an aromatic-heavy to an olefin-heavy product regime. • Artificial aging of the zeolite by steam treatment, increases the catalyst lifetime. [ABSTRACT FROM AUTHOR]

Reactive molecular dynamics simulations were conducted to investigate the tribological behavior between two amorphous iron oxide substrates with octene molecules confined between them. The results revealed that higher temperatures facilitated the degradation and oxidation of octene molecules, leading to an increased quantity of reaction products such as water and oxidation products like alcohols. Due to the obstructive action of water molecules, the octene and its oxidation products were able to adsorb onto the substrate surfaces, resulting in the formation of a stably adsorbed carbon-based tribofilm at elevated temperatures. In addition, the water layer also significantly reduces friction by preventing direct contact between the carbon-based tribofilm, even though only a small amount of octene molecules are present at the interface. [Display omitted] [ABSTRACT FROM AUTHOR]

The article deals with preparation, properties and usage of ethylene‐octene copolymers/clay films. Different properties of two types of ethylene‐octene copolymers (Engage 8540 and Engage 8842) with 17 and 45 wt% of octene (EOC‐17 and EOC‐45) were compared in nanocomposites with two types of clays—Cloisite 93A and Dellite 67. The aim was to evaluate the influence of (nano)filler type on ethylene‐octene nanocomposites properties. Mechanical and thermal properties, morphology, and UV radiation degradation were observed. Furthermore, permeability of three different gasses was determined. EOC nanocomposites perform a higher elongation at break, especially EOC‐45. Dynamic Mechanical Analysis (DMA) showed an increase of E′ modulus of all nanocomposites in a wide range of temperatures compared to pure EOC. Intercalation of nanofillers was studied by transmission electron microscopy (TEM) and X‐ray diffraction (XRD). It has been proved that EOC‐45 has a better dispersion EOC‐17. DSC analysis showed a shift in a crystallization temperature for EOC‐17, where the nanofiller acted as a nucleation agent due to the worse dispersion. Barrier properties were improved by almost 100% by addition of organoclay for all measured gasses; they were best for EOC‐17 nanocomposites due to a higher crystallinity. XRD together with transmission electron microscopy (TEM) showed much better dispersion for EOC‐45 nanocomposites. Fourier transform infrared spectroscopy (FTIR) and accelerated UV aging showed CO peaks for EOC nanocomposites. POLYM. COMPOS., 39:4581–4593, 2018. © 2017 Society of Plastics Engineers [ABSTRACT FROM AUTHOR]

Abstract Ethylene/1-olefin copolymers with a 1-olefin content >10 wt%, known as polyolefin plastomers (POP) and elastomers (POE), are materials of growing commercial importance. A relevant example are ethylene/1-octene (EO) copolymers. The thermal properties of nine 1-octene based POP/POE were studied by differential scanning calorimetry (DSC). The obtained thermograms were indicative of an asymmetric chemical composition distribution (CCD), triggering further investigations. At first, analytical temperature rising elution fractionation (a-TREF) was employed which gave further evidence of an asymmetric CCD for some samples. Given the low crystallinity of many of the samples, their CCD could, however, only be studied by high temperature high performance liquid chromatography (HT-HPLC). The hypothesis about an asymmetric CCD could be confirmed for all samples. The results were compared with theoretically calculated CCD (Stockmayer distributions) which are symmetrical. In a semiquantitative comparison, the main peak of the experimental CCD was found to be in good agreement with Stockmayer distributions. Graphical abstract Image Highlights • Chemical composition distribution studied by a-TREF, SGIC and TGIC. • Broad chemical composition distributions with characteristic shape found. • SGIC shows broader application range and higher resolution than TGIC. • Experimental results in good agreement with theory but clear differences revealed. [ABSTRACT FROM AUTHOR]

Abstract A method for assessing the puzzling molecular architecture of ethylene/1-octene multi-block copolymers, synthesized via chain-shuttling technology, is proposed. They are commercial elastomers characterized by alternating segments with low (hard blocks) and high (soft blocks) octene concentration. Our molecular assessment allows determining plausible value for the average length of blocks and number of blocks/chain, setting the basis for a definitive elucidation of structure-properties relationships of these elusive systems. Namely, the molecular basis which explains the similar crystallization properties, and the large difference in mechanical properties of this class of copolymers is unveiled thanks to our approach. We demonstrate that at 25 °C we have similar values of Young modulus and deformation at break higher than 1400%, but large strain hardening before breaking or flat mechanical behavior up to the break, depending on the short or long average block length of the multiblock copolymers, respectively, coupled with a high or low number of blocks/chain, respectively. At 60 °C these differences are amplified entailing no strain hardening but preservation of high ductility for copolymers with short average block length and high number of blocks/chain, remarkable decrease of strain at break of about two orders of magnitude (from ≈2000 to ≈90%) for copolymers with long average block length and lower number of blocks/chain. Graphical abstract Image 1 Highlights • Elastomers by chain shuttling technology have polydisperse multiblock structure. • The properties depend on the average length of blocks and number of blocks/chain. • A method is set up for the evaluation of these elusive parameters. • They verify the rules that govern the best efficiency of elastomeric networks. • Many short blocks show better mechanical properties than few long blocks. [ABSTRACT FROM AUTHOR]

The metal complex catalysis with participation of unsaturated hydrocarbons gains great interest because of ecological aspect and a possibility of re-using of the catalyst. It has a number of advantages in comparison with a heterogeneous catalysis, such as high activity and selectivity, low temperatures of reaction and pressure. A palladium-polyvinylpyrrolidone complex was synthesized and characterized by potentiometry, conductometry, mass-, and IR-spectroscopy. The complex was tested for catalytic activity in reaction of octene-1 oxidation by inorganic oxidizers (KIO4, NaBrO3, Na2S2O8, K2S2O8) in dimethylsulfoxide or dimethylformamide under mild conditions. The reaction product was octanone-2, obtained in good yield (80-98 %) and characterized by gas chromatography and mass spectrometry. The catalysts can be easily recycled five consecutive runs without significant loss of catalytic efficiency. The use of different surface analysis techniques, such as: Scanning Electron Microscopy (SEM) and Energy- Dispersive X-ray spectroscopy (EDX), led to a better understanding of the polymer promoting effect. [ABSTRACT FROM AUTHOR]

A very efficient and highly selective rhodium catalyst with a C 2 -symmetric BINOL-derived diphosphoramidite ligand for hydroformylation of 1-octene has been developed. At mild conditions (50 °C and 10 bar H 2 /CO) a very active rhodium catalyst has been obtained which produces over 99% of aldehydes with 98.2% n -regioselectivity. The spectroscopic characterization of the hydridorhodium catalytically active species showed that the diphosphoramidite ligand coordinates bis-equatorially in the trigonal bipyramidal rhodium complex, which coupled with its π-acceptor capacity might account for the high catalyst performance. [ABSTRACT FROM AUTHOR]

Abstract: The bioorthogonal cleavage of allylic carbamates from trans‐cyclooctene (TCO) upon reaction with tetrazine is widely used to release amines. We disclose herein that this reaction can also cleave TCO esters, carbonates, and surprisingly, ethers. Mechanistic studies demonstrated that the elimination is mainly governed by the formation of the rapidly eliminating 1,4‐dihydropyridazine tautomer, and less by the nature of the leaving group. In contrast to the widely used p‐aminobenzyloxy linker, which affords cleavage of aromatic but not of aliphatic ethers, the aromatic, benzylic, and aliphatic TCO ethers were cleaved as efficiently as the carbamate, carbonate, and esters. Bioorthogonal ether release was demonstrated by the rapid uncaging of TCO‐masked tyrosine in serum, followed by oxidation by tyrosinase. Finally, tyrosine uncaging was used to chemically control cell growth in tyrosine‐free medium. [ABSTRACT FROM AUTHOR]

The influence of 1-butyl-3-methylimidazolium bis(trifluromethanesulfonyl)imide ([BMIM][NTf 2 ]) on Cu/γ-Al 2 O 3 was investigated for the competitive hydrogenation of octanal in the presence of octene in a continuous flow reactor. The role of the solid catalyst was investigated by comparing the activities of one-step (N15Cu) vs two step (2N15Cu) wet impregnated catalyst. Characterization techniques included nitrogen physisorption, temperature programmed studies, electron microscopy and X-Ray Photoelectron Spectroscopy which were used to determine the catalyst properties and metal-ionic liquid interaction of the uncoated and IL coated catalysts. The Cu SCILL catalyst (solid catalyst with an ionic liquid layer) showed enhanced catalytic performance as compared to the uncoated catalyst. Under optimized conditions, the 2N15Cu SCILL catalyst favoured the desired hydrogenation of the octanal, whilst minimizing the undesired octene hydrogenation. The octene conversion decreased from 26% to 6% over the SCILL catalyst. The presence of the ionic liquid also increased the selectivity towards the desired product, 1-octanol, from 93.5% over the uncoated catalyst to 99.8% over the SCILL catalyst. Investigation into the interaction between the copper and the ionic liquid revealed that the ionic liquid is physically adsorbed onto the catalyst’s surface, and induced changes in the SCILL catalysts surface acidity, BET surface area and hydrogen-metal interaction. It seems likely that the thermal and chemical properties of the ionic liquid also contributed to the SCILL catalyst behaviour, for example, the polar nature of the ionic liquid favours the diffusion of octanal as opposed to octene within the ionic liquid layer. This results in a greater selectivity towards C O hydrogenation which is desired. [ABSTRACT FROM AUTHOR]

Abstract: Kinetic and copolymer composition investigations of the free radical copolymerization of 1‐octene with glycidyl methacrylate are reported. The chemical structure of the obtained copolymers is elucidated by 1H, 13C, heteronuclear single quantum coherence nuclear magnetic resonance (NMR) and infrared spectroscopies. 1H NMR measurements indicate that a maximum statistical incorporation of 1‐octene in the copolymer chain of 32 mol% is obtained when 90 mol% of this comonomer is used in the initial monomer feed of the copolymerization reaction. Furthermore, the reactivity ratios of this comonomer system are estimated using the obtained experimental data, which are fitted to the integral form of the copolymerization equation utilizing a nonlinear least squares approach. To the best of knowledge, this is the first report on the reactivity ratios of this specific comonomer system. To evaluate the potential of the obtained materials as dispersants, the effect of the polymer concentration on the dispersion of copper nanopowders in organic solvents is studied for a copolymer with a 1‐octene composition of 25 mol%. [ABSTRACT FROM AUTHOR]

This work reports, reductive-hydroformylation of 1-octene to nonanol in the presence of fine fibrous cobalt oxide (Co 3 O 4 ) nano-catalyst prepared via urea reduction method under phosphine-free and additive free condition. Co 3 O 4 nano-catalyst was prepared by the wet chemical method and was characterized using various instrumental techniques like FEG-SEM, EDS, XRD, TPR and FTIR. The effects of various reaction parameters such as temperature, synthesis gas (CO/H 2 ) pressure/ratio, catalyst loading, solvent and time were studied. The reaction was successfully achieved in tetrahydrofuran (THF) as the solvent medium. This reaction believed to takes place through the generation of HCo x (CO) y active catalyst species. The Co 3 O 4 nano-catalyst could be recycled up to three consecutive cycles. [ABSTRACT FROM AUTHOR]

The chain-walking polymerization of linear internal alkenes (i.e., trans-2-, 3-, and 4-octenes) using a-diimine nickel catalysts activated with modified methylaluminoxane (MMAO) was studied in comparison with the corresponding terminal alkene polymerization. The rates of polymerization were found to decrease in the following order: 1-octene > 4-octene ≥ 2-octene ≫ 3-octene. The obtained branched poly(2-octene)s and poly(4-octene)s with high molecular weight and Mw/Mn less than 2 were amorphous polymers with low glass transition temperature (Tg) of approximately -66 °C. At 0 °C, 4-octene polymerized in a living/controlled manner. The NMR analyses of the polymers showed that the chain-walking polymerization of 4-octene gave periodically branched polymers with the constant branching density, while that of 2-octene gave the polymer possessing fewer branches than the expected value due to monomer-isomerization. The (n+2),(n+3)- and (n+3),(n+2)-insertions of the internal (n+2)-alkene [CH3(CH2)nCH-CH(CH2)mCH3] followed by chain-walking were confirmed by the 13C NMR analysis of the produced polymers. [ABSTRACT FROM AUTHOR]

A convenient and cost‐effective synthetic access to cyclooctyne and trans‐cyclooctene derivatives is described. A cyclopropanation step using copper powder in place of Rh2(OAc)4 as catalyst and a symmetric diazomalonate resulted in a drastic decrease in the overall cost of the synthesis. Further derivatizations allowed us to characterize, for the first time, the structure of a BCN analogue by X‐ray crystallography, and to obtain a library of derivatives that could potentially be useful for applications in metal‐free click chemistry. [ABSTRACT FROM AUTHOR]

Effect of sonication time on the synthesis of the CdS nanoparticles within the matrix obtained through the covalent functionalization of multiwall carbon nanotube (MWCNT) with maleic anhydride (MA) - 1-octene copolymer was investigated. Cadmium chloride and thiourea were used as the raw materials. MWCNTs used for the matrix were synthesized by Catalytic Chemical Vapor Deposition using Fe-Co/Al2O3 as the catalyst. The obtained nanostructures were characterized by FTIR, XRD, Raman spectroscopy, TEM, SEM, TG and UV-Vis spectroscopy. Electrophysical properties of the polymer nanocomposites obtained using different periods of time for sonication were comparably investigated. The average CdS particle diameter was between 3.9-7.9 nm as confirmed independently by TEM and XRD. UV-Vis spectroscopy revealed that the obtained nanostructures are appropriate base materials for making optical devices. [ABSTRACT FROM AUTHOR]

A pair of homochiral manganese-based coordination polymers [Mn(H 2 O) 2 (bpy)(L-DBTA)] ( L-1 ) and [Mn(H 2 O) 2 (bpy)(D-DBTA)]( D-1 ): Syntheses, crystal structures and catalytic properties for the selective oxidation of cis -cyclooctene. The homochiral manganese-based 3D supermolecule framework exhibits high catalytic activity (38.85% conversion based on cis -cyclooctene and 76.13% selectivity for epoxycyclooctane) and stability for selective oxidation of cis -cyclooctene in the absence of solvent using TBHP as radical initiator and oxygen (in the air) as oxidant at 80 °C. [ABSTRACT FROM AUTHOR]

Small gold nanoparticles (AuNPs) have recently shown potential to act as a catalyst for oxidation reactions mediated by free radicals, with their role postulated to be facilitating hydrogen abstraction by gold superoxo species and/or activation of hydroperoxides. Cyclooctene oxidation using molecular oxygen as the oxidant at 373 K showed high selectivity to the epoxide product, cyclooctene oxide, with either tert-butyl hydroperoxide as an initiator or in the presence of small AuNPs (5-8 atoms). While previous studies have investigated the mechanism leading to high epoxide selectivity using density functional theory, a full microkinetic model was developed in this work using automated network generation to determine the relative contributions of elementary reactions and the role of AuNPs. A cycle of radical addition of peroxy and alkoxy radicals with subsequent epoxidation reactions can justify the observed activity and selectivity to epoxide at multiple temperatures and initiator concentrations. The alcohol, ketone, and hydroperoxide minor products are formed when the peroxy and alkoxy radicals perform hydrogen abstraction or β-scission. The overall selectivity is determined by the competition between the addition and hydrogen abstraction reactions. With the underlying homogeneous reaction model validated, the effect of the AuNPs was determined through an expanded model that includes cycles for both hydrogen abstraction by superoxo gold species and hydroperoxide decomposition via species derived from AuNPs. The model suggests that hydrogen abstraction by the superoxo gold species dominates at short times compared to homogeneous initiation, increasing the activity during the induction period and reducing the time before radical chain oxidation commences. On the time scale of an hour, hydroperoxide decomposition is significantly catalyzed by the presence of gold species, increasing the overall rate of chain propagation. [ABSTRACT FROM AUTHOR]

The impact of the organic species in the synthetic gel of ZSM-5 on the distribution of Al atoms in the MFI framework and catalytic performance was investigated; ZSM-5 zeolites were synthesized by exclusively using TPAOH, and Na cations with PET to elucidate how the distribution of Al atoms is governed by the types of organic species in the synthetic gel. The distribution of Al atoms was investigated by 27 Al MAS NMR technique and constrain index (CI). Catalytic cracking of 1-octene over the ZSM-5 catalysts was carried out to estimate “hydrogen transfer coefficient (HTC) and cracking mechanism ratio (CMR) values”. We found that HTC and CMR values are dependent on the distribution of Al atoms. The fine-control of Al distribution in the MFI structure could improve the tolerance for coke deposition in 1-octene cracking. [ABSTRACT FROM AUTHOR]

A deterministic modelling approach is developed to predict the internal structure of gradient copolymer chains. A key innovation of the modelling approach is the introduction of a positional variable that gives direct access to quantitative gradient characteristics: the ensemble average composition and the gradient deviation. This positional variable is used to develop multi-dimensional population balance equations that can be solved numerically to calculate gradient quality measures. The methodology is illustrated using the gradient copolymerisation of ethylene and 1-octene via coordinative chain transfer mechanism, which is representative of a variety of polymerisation schemes for gradient copolymers. Simulation results are validated with those obtained by stochastic simulations which, until now, were the only means of predicting detailed gradient quality. [ABSTRACT FROM AUTHOR]

The expeditious route for the synthesis of γ-butyrolactone fused cyclooctene starting from the γ-butyrolactone fused cyclopentane through bicyclo[4.2.1]nonan-9-one is reported. Retro-Dieckmann's condensation of bicyclo[4.2.1]nonan-9-one in presence of sodium methoxide and methanol furnished γ-butyrolactone fused cyclooctene in good yield. Surprisingly, the stereochemistry of ringjunction of γ-butyrolactone fused cyclooctene is different from the γ-butyrolactone fused cyclopentane, and the position of new ester group, which were confirmed unambiguously by X-ray analysis. [ABSTRACT FROM AUTHOR]

The metalloradical activation of ortho-benzallylaryl N-tosyl hydrazones with [Co(TPP)] (TPP=tetraphenylporphyrin) as the catalyst enabled the controlled exploitation of the single-electron reactivity of the redox non-innocent carbene intermediate. This method offers a novel route to prepare eight-membered rings, using base metal catalysis to construct a series of unique dibenzocyclooctenes through selective Ccarbene−Caryl cyclization. The desired eight-membered-ring products were obtained in good to excellent yields. A large variety of aromatic substituents are tolerated. The proposed reaction mechanism involves intramolecular hydrogen atom transfer (HAT) to CoIII-carbene radical intermediates followed by dissociation of an ortho-quinodimethane that undergoes 8π cyclization. The mechanism is supported by DFT calculations, and the presence of radical-type intermediates was confirmed by trapping experiments. [ABSTRACT FROM AUTHOR]

Three dendritic PNP ligands with ethylenediamine, 1,4-butanediamine, 1,6-diaminohexane as bridged groups are synthesized in good yields, respectively. Three dendritic PNP chromium complexes ( C1 - C3) are prepared with the ligands and chromium( III) chloride tetrahydrofuran complex (CrCl3( THF)3) as materials. The dendritic PNP ligands and the synthetic chromium complexes are fully characterized by spectroscopic and analytical methods. All chromium complexes activated with methylaluminoxane ( MAO) exhibited moderate activities on ethylene oligomerization (7.90 × 104 - 2.15 × 105 g (mol Cr h)−1] and had better selectivity for C6 and C8 oligomer, reaching up to 81%. The chromium complex ( C1) activated with diethylaluminium chloride (Et2AlCl) has higher catalytic activity than the chromium complex C1 activated with MAO, although the chromium complex ( C1) activated with Et2AlCl had lower selectivity for C6 and C8 oligomer. The effects of solvent and reaction parameters on ethylene oligomerization are also studied using the chromium complex C1 as pre -catalyst and MAO as co -catalyst. Under optimized conditions ([complex] = 2 μmol, Al/Cr = 500, 25 °C, 0.9 MPa ethylene, 30 min), the catalytic activity of complex C1 in toluene is 2.15 × 105 g (mol Cr h)−1 and the selectivity for C6 and C8 oligomer is 36.76%. In addition, the structure of complexes significantly affects both the catalytic activity and the selectivity on ethylene oligomerization. [ABSTRACT FROM AUTHOR]

The article proposes a novel and eco-friendly method for synthesizing SAPO-11 in ethylene glycol (EG) and supercritical carbon dioxide (ScCO 2 ). The method incorporates ScCO 2 into EG to decrease the solubility of SAPO-11 precursors in EG and thereby forms a highly supersaturated solution of SAPO-11 precursors. The as-synthesized SAPO-11 possesses smaller particles, a larger external surface area, and a larger number of acid sites than the SAPO-11 synthesized in EG and the SAPO-11 synthesized in water and ScCO 2 , respectively. These advantages of the as-synthesized SAPO-11 endow the corresponding catalyst with superior dibranched isomer selectivity and low cracking selectivity during 1-octene hydro isomerization. [ABSTRACT FROM AUTHOR]