Olefinic Carbon Research Articles

Critical role of sodium migration in iron-based FT- zeolite tandem catalyst system for syngas hydrogenation to gasoline

Exploration the role of promotor in the Fischer-Tropsch zeolite (FTO-ZEO) tandem catalyst systems is of paramount importance in improving the selectivity of target products. Herein, by varying the contents of Na promotor in xNa-FeOx, the evolution of Na in FTO-ZEO system during reaction and the resultant catalytic performance for FT synthesis have been investigated. When the content of Na falls in the range of 0.5–5 %, the syngas conversion performance on bare FeOx catalysts reaches a performance-platform period, while that on tandem catalysts show a volcano-like trend. With a set of control experiments, it is speculated that there is a migration process of Na from xNa-FeOx to the H-ZSM-5 moiety. The changed acidity of H-ZSM-5 causes the transformation of products toward higher carbon alkanes and aromatics in the gasoline range with a selectivity of 71.5 %. This work makes an important progress by showing the phenomenon of Na migration during reaction, which puts forward the influence of promoters on FTO-ZEO system and gives a new insight of zeolites modification.

Solid state synthesis of bispyridyl-ferrocene conjugates with unusual site selective 1,4-Michael addition, as potential inhibitor and electrochemical probe for fibrillation in amyloidogenic protein

Destabilization of protein's native conformation to intermediates rich in β-sheet structure may lead to amyloid fibrillation involving a complex process of aggregation that are primarily responsible for various neurodegenerative disorders. Design of flexible, functional molecules capable of disruption or inhibition of fibrillar aggregates at their initial stages can be an effective approach to restrict or prevent amyloid related diseases. In this perspective, strategic association of ferrocenyl based electro-active moiety with heterocyclic rings can generate flexible, biocompatible molecular system with significant role in protein interactions, electrochemical monitoring and improved biological activity. Therefore, synthesis of molecules containing multi-pyridine ring framework conjugated to a ferrocenyl scaffold have been explored using a unique solid state, redmud supported, solvent free reaction method which led to the formation of ferrocenyl bis-pyridylenone (2) and a rare class of ferrocene based 1,4-Michael addition compound (3). The 1,4-Michael addition attack at an olefinic carbon with bulkier, electron donating ferrocenyl substituent has been unprecedented. Inhibitory potential of di-functionalized ferrocenyl-bispyridylenone conjugate (2) against amyloid fibrillation and its ability to serve as electrochemical probe on the disaggregation process of BSA have been explored. The study revealed significant inhibition of amyloid fibrils during aggregation process and also showed disruption of pre-formed BSA fibrils. The redox active inhibitor molecule was also used as potential electrochemical probe to monitor the inhibition of the fibrillation process. Molecular dynamics simulation confirmed distinct hydrogen bond interactions between the inhibitor compound and the A chain of BSA and revealed enough conformational stability of the protein-inhibitor complex.

Effect of Interactions between Alkyl Chains and Solvent Structures on Lewis Acid Catalyzed Epoxidations

Solvent molecules within zeolite pores provide interactions that influence the stability of reactive intermediates and impact rates and selectivities for catalytic reactions. We show the kinetic and thermodynamic consequences of these interactions and reveal their origins using alkene epoxidations in titanium-substituted *BEA (Ti-BEA) zeolites. Epoxidation turnover rates vary widely among primary n-alkenes (C6–C18) in hydrophilic (Ti-BEA-OH) and hydrophobic (Ti-BEA-F) catalysts in aqueous acetonitrile (CH3CN). Apparent activation enthalpies (ΔHapp‡) and entropies (ΔSapp‡) increase with alkene carbon number in both catalysts; however, the span of ΔHapp‡ values in Ti-BEA-OH (68 kJ mol–1) greatly exceeds that in Ti-BEA-F (18 kJ mol–1). These trends, and commensurate gains in ΔSapp‡, reflect the displacement and reorganization of solvent molecules that scale with the size of transition states and the numbers of solvent molecules stabilized by silanol defects near active sites. Experimental and computational assessments of intrapore solvent composition from 1H NMR, infrared spectroscopy, and grand canonical molecular dynamics (GCMD) simulations show that Ti-BEA-OH uptakes larger quantities of both CH3CN and H2O than Ti-BEA-F. The Born–Haber decomposition of simulated enthalpies of adsorption (ΔHads,epox) for C6–C18 epoxides attributes ΔHads,epox that become more endothermic for larger adsorbates to the displacement of greater numbers of solvent molecules bound to silanol defects into the bulk solvent. A strong correlation between ΔHapp‡ and ΔHads,epox (from GCMD and isothermal titration calorimetry) gives evidence that the disruption of solvent structures provides excess thermodynamic contributions (e.g., Gε) that depend on the solvent composition in the pores, the excluded volume of reactive species, and the density of silanol groups near active sites. Altering Gε values offers opportunities to control selectivities and rates of reactions through the design of extended active site environments.

Novel Unsymmetric 3,5-Bis(benzylidene)-4-piperidones That Display Tumor-Selective Toxicity.

Two series of novel unsymmetrical 3,5-bis(benzylidene)-4 piperidones 2a–f and 3a–e were designed as candidate antineoplastic agents. These compounds display potent cytotoxicity towards two colon cancers, as well as several oral squamous cell carcinomas. These compounds are less toxic to various non-malignant cells giving rise to large selectivity index (SI) figures. Many of the compounds are also cytotoxic towards CEM lymphoma and HL-60 leukemia cells. Representative compounds induced apoptotic cell death characterized by caspase-3 activation and subG1 accumulation in some OSCC cells, as well as the depolarization of the mitochondrial membrane potential in CEM cells. A further line of inquiry was directed to finding if the SI values are correlated with the atomic charges on the olefinic carbon atoms. The potential of these compounds as antineoplastic agents was enhanced by an ADME (absorption, distribution, metabolism, and excretion) evaluation of five lead molecules, which revealed no violations.

Probing the Free Energy Landscape of Organophotoredox-Catalyzed Anti-Markovnikov Hydrofunctionalization of Alkenes.

Experimental 13C kinetic isotope effects (KIEs) provide unprecedented mechanistic insight into three intermolecular anti-Markovnikov alkene hydrofunctionalization reactions─hydroesterification, hydroamination, and hydroetherification─enabled by organophotoredox catalysis. All three reactions are found to proceed via initial oxidation of the model alkenes to form a radical cation intermediate, followed by sequential nucleophilic attack and hydrogen-atom transfer to deliver the hydrofunctionalized product. A normal 13C KIE on the olefinic carbon that undergoes nucleophilic attack provides qualitative evidence for rate-limiting nucleophilic attack in all three reactions. Comparison to predicted 13C KIE values obtained from density functional theory (DFT) calculations for this step reveals that alkene oxidation has partial rate-limiting influence in hydroesterification and hydroamination, while the nucleophilic attack is solely rate-limiting in the hydroetherification reaction. The basic additive (2,6-lutidine) activates the nucleophile via deprotonation and is an integral part of the transition state for nucleophilic attack on the radical cation, providing an important design principle for the development of asymmetric versions of these reactions. A more electron-rich pyridine base (2,6-dimethoxypyridine) exhibits considerable rate enhancements in both inter- and intramolecular hydrofunctionalization reactions.

Ultrasonic extraction of oil shale bitumen and study of its structural features using GC-MS and NMR techniques

ABSTRACT Oil shale is a raw material that is considered to be an alternative fossil fuels and it is widely used in producing energy and chemicals. Oil shale bitumen identification are not widely described in literature. This article tackles the structural elucidation of oil shale bitumen using gas chromatography-mass spectrometry (GC-MS) and nuclear magnetic resonance (NMR) spectroscopy with a short sample preparation step, based on ultrasonic-assisted liquid extraction. The ultrasonic-assisted extraction was examined in terms of solvent type and volume, sample size, sonication time and temperatures. A bitumen recovery of 17.7 wt% dmmf (dry-mineral-matter-free) was achieved when 0.50 g of shale was mixed with 20 mL THF and sonicated for 10 min at ultrasonic power of 120 W at 45°C. GC-MS of the bitumen showed high polar oxygenated compounds with more than 20 wt% being esters and ethers. Small concentrations of thiols and amides have been also found. The structural identification of bitumen was carried out using 1H-NMR and 13C-NMR and the results showed highly aliphatic character bitumen, consisting of aromatic, paraffinic, naphthenic and olefinic hydrogen and carbon atoms. These results suggested that ultrasonic solvent extraction could be an efficient and environment-friendly method for obtaining of bitumen from oil shale.

Regioselective Oxidative Halotriflamidation of Dienes and Trienes as a Route to New Amidines and Heterocycles

AbstractComparative analysis of halotriflamidation of linear and cyclic dienes and trienes in different oxidative systems revealed a large variety of reactivity patterns. With linear dienes the haloamidation or solvent (MeCN) interception products or the products of their further transformations are formed. The NBS‐induced reactions of conjugated cyclic dienes (cyclopentadiene, 1,3‐cyclohexadiene, 1,3‐cyclooctadiene) regioselectively afford bromoamidines at only one double bond with solvent interception. Dicyclopentadiene also gives bromamidine at the bicycloheptene double bond. With linear 5‐methylhepta‐1,3,6‐triene, 1,4‐conjugate addition occurs with solvent interception and the halogen atom directed to the terminal olefinic carbon. Cyclododeca‐1,5,9‐triene reacts with triflamide differently depending on the oxidant to give amidine or azabicyclo[8.2.1]tridec‐5‐ene structure. The synthesized bromoamidines were converted into the corresponding imidazolines in close to quantitative yield.

Copper-based deep eutectic solvents (Cu-DES) assisted the VPO catalyst as a structural and electronic promoter for n-butane selective oxidation

Currently, deep eutectic solvents (DESs), as an exclusive class of ionic liquid analogs, are extensively employed in various fields. Herein, vanadium phosphorus oxide (VPO) catalysts assisted by copper-based deep eutectic solvent (Cu-DES) as an electronic promoter and structure directing agent were ingeniously synthesized and exploited in the selective oxidation of n-butane to maleic anhydride (MA). The DES is efficient, cost effective and highly green compared to conventionally use metal inorganic modifiers. Cu-DES was prepared from a eutectic mixture of an organic salt (ChCl) and a metal salt hydrate/metal salt of cupric (Cu(NO3)2.3H2O, CuCl2) and cuprous (CuCl) salt with a molar ratio of 1:1–1:3, which notably improved the catalytic performance compared to that of an unpromoted VPO catalyst. The MA selectivity and n-butane conversion of Cu–DES–VPO increased significantly, while the COx (CO and CO2) selectivity decreased. FTIR, DSC, XRD, SEM, EDS, TEM, Raman, TGA, XPS, and NH3-TPD characterization techniques were utilized to fully analyze the DES, precursor and catalyst to explore MA selectivity. This work shifts the significant increase of 13% n-butane conversion, 11% MA selectivity and 16% MA mass yield, which greatly influences low carbon alkane utilization. Importantly, the CO: CO2 ratio is reduced from 2.02 to 1.62, which is more beneficial for chemical plants as well as green environments.

Density functional theory calculations of δ(13 C) and δ(1 H) chemical shifts and 3 J(13 COO1 H) coupling constants as structural and analytical tools in hydroperoxides: Prospects and limitations of 1 H13 C heteronuclear multiple bond correlationexperiments.

Density functional theory (DFT) calculations of δ(13 C) and δ(1 H) chemical shifts and 3 J(13 COO1 H) coupling constants of three model hydroperoxides of the naturally occurring cis-11-OOH and trans-9-OOH isomers of oleate and 9-cis, 11-trans-16-OOH endo hydroperoxide of methyl linolenate are reported. The computational δ(OOH) for various functionals and basis sets were found to be nearly identical for the cis/trans geometric isomers. The chemical shifts of the methine CHOOH protons and carbons, on the contrary, are highly diagnostic for the identification of cis/trans geometric isomerism. The chemical shifts of the olefinic protons and carbons strongly depend on the orientation of the hydroperoxide unit relative to the double bond and, thus, of importance in conformational analysis. The results are in very good agreement with the available experimental data. For the various diastereomeric pairs of the model endo-hydroperoxide, the strongly deshielded OOH resonances, due to the presence of an intramolecular hydrogen bond between the hydroperoxide proton and an oxygen of the endo-peroxide ring, along with the δ(CHOOH), are highly diagnostic for identification and structure elucidation of complex erythro- and threo- diastereomeric pairs of endo-hydroperoxides; the computational results are in very good agreement with the available experimental data. The 3 J(13 COO1 H) coupling constants were found to be < Hz for the cis-trans geometric models and < Hz for the endo-hydroperoxide and, thus, unimportant in stereochemical analysis. Sharp resonances of the hydroperoxide protons, with Δν1/2 < 3 Hz, are required for the successful implementation of the 1 H13 C heteronuclear multiple bond correlation (HMBC) technique.

Synthesis and catalytic behavior of nickel heterogenized in covalent organic frameworks as precatalysts in ethylene oligomerization

Two covalent organic frameworks (COFs), as the supports of transition metal catalysts, were prepared and coordinated with nickel to synthesize two precatalysts for ethylene oligomerization. The chemical structure of sub-constructing unit had a significant influence on the specific surface area and the catalytic performance of covalent organic frameworks supported nickel(Ⅱ) catalysts. Two COFs were stacked in lamellae, and the specific surface area and the pore volume of COF with p-phthalaldehyde as sub-constructing unit were far larger than those of COF with butanedione as sub-constructing unit. The catalyst with a larger specific surface area had a higher catalytic activity and a higher selectivity of low carbon olefins in ethylene oligomerization because of a higher specific surface areas and larger pore structure for ethylene diffusion and mass transfer. Two catalysts can be reused at least three times without considerable loss in the catalytic activity and the selectivity toward short-chain α-olefins.

Mechanical Insights into Activation of Peroxides by Quinones: Formation of Oxygen-Centered Radicals or Singlet Oxygen.

In this work, the mechanism of the activation of peroxides by quinones has been investigated through quantum chemical calculations. Hydrogen peroxide (H2O2), peroxomonosulfate (PMS), peracetic acid (PAA), and CH3OOH were chosen as the model peroxides and p-benzoquinone (p-BQ) and tetrachloro-1,4-benzoquinone (TCBQ) as the model quinones. The nucleophilic attack of peroxides can occur on the carbonyl and olefinic carbons of quinones. For p-BQ, the nucleophilic attack of HO2-, CH3OO-, PMS, and PAA might prefer to occur on the carbonyl carbons, which have more positive atomic charges. Then, further transformation could not be induced from the addition of HO2- and CH3OO- to p-BQ. Comparatively, singlet oxygen (1O2) could be generated in the cases of PMS and PAA. For TCBQ, the chlorine atoms cause the olefinic carbons to carry more positive atomic charges, and then, HO2- preferred to add to the olefinic carbons, which might induce the formation of the hydroxyl radical (•OH). The activation of PMS by TCBQ was similar to that by p-BQ, with the kinetical feasibility of 1O2 formation. These findings may provide some theoretical insights into the reaction of peroxides with quinones, especially into the interconnection between the substitutes and the formation of oxygen-centered radicals (e.g., •OH) and 1O2.

Coordinated Control of PM2.5 and O3 in Hangzhou Based on SOA and O3 Formation Potential

A continuous observation campaign was carried out with the Syntech Spectras GC955 volatile organics online monitoring system from March 1, 2019 to May 31, 2019 in Hangzhou. The constituent features of VOCs, the preferred VOCs species, and VOCs characteristic pollutant ratios were analyzed. The results showed that alkanes were the most important component in the volume fraction of VOCs, accounting for 62.40%. C2-C6 alkanes, benzene series, ethylene, and acetylene were the key species of VOCs. Olefins and aromatics were the main contribution components of OFP, with contribution rates of 41.35% and 37.50%, respectively. Aromatics were the main contributors to SOA, with a contribution rate of more than 90%. Low carbon alkanes, low carbon olefins, and benzene series were the key contributing species of OFP. Controlling toluene, m/p-xylene, and o-xylene is the key to the coordinated control of O3 and PM2.5. VOCs in the atmosphere of the sampling point were not only affected by motor vehicle exhaust but were also significantly affected by industrial emissions, such as solvents.

Selective molecular characterization of olefins in hydrocarbon mixtures by Ag+ complexation ESI high-resolution mass spectrometry

Molecular characterization of olefins in the complex hydrocarbon mixture is of vital importance for the various hydrocarbon upgrading processes. According to the strong interaction of Ag+ with unsaturated hydrocarbon, Ag+ complexation was adopted in this study as a tool to achieve selective olefin ionization in electrospray ionization (ESI). High-resolution mass spectrometry (HR MS) was used to characterize ionized olefin molecular composition. Various model compounds, including paraffins, naphthenes, olefins, and aromatics, were used to verify the ionization selectivity. The observed olefin carbon number distribution from Ag+ complexation ESI HR MS was in agreement with those from gas chromatography-mass spectrometry equipped with the electron impact ion source (GC-EI-MS). The proposed method can be conveniently used for direct molecular characterization of olefins in mixtures without time-consuming olefin pre-separation or chemical derivatization. Olefins in coker diesel, coal tar liquid, and Fischer-Tropsch wax were successfully analyzed by the proposed method.

Process parameter optimization for integrated process of coal pyrolysis with dry reforming of low carbon alkane over Ni/La2O3–ZrO2

Integrated coal pyrolysis with dry reforming of low carbon alkane (CP-DRA) is a useful method to improve tar yield. The development of catalyst is the key for the integrated process. Ni/La2O3–ZrO2 shows a good performance with La/Zr ratio being 4 in which La2Zr2O7 is benefit to improve stability and La2O3 is helpful to inhibit carbon deposition, and the highest tar yield being 20.5 wt% at 600 °C was obtained which is 1.18 times of that under N2. Other process parameters were optimized to improve tar yield of CP-DRA by using this catalyst. Results showed that the increase of Ni loading in catalyst and gas flow rate, and the decrease of space velocity can improve tar yield of CP-DRA. The 10.0 wt% Ni loading with 1.0 g catalyst dosage (space velocity 30600 h−1) and 8:1 CH4/C2H6 ratio are optimal conditions for CP-DRA with high tar yield (20.5 wt%) and less carbon deposition (0.1 g/gcat). The tar was characterized by simulated distillation and NMR which shows that tar of integrated process contains more alkyl-aromatics than that under N2 by stabilizing aromatic radicals.

Human peripheral blood mononuclear cells targeted multidimensional switch for selective detection of HSO3− anion

A new ratiometric π-conjugated luminophore with donor-acceptor (D- π- A) network CM {(E)-2-(4-(2-(9-butyl-9H-carbazol-3-yl)vinyl)benzylidine)malononitrile} has been synthesized by malononitrile conjugated carbazole dye with an intervening p-styryl spacer. Here, p-styryl conjugated malononitrile is used as a recognition site for the detection of HSO3− with a fast response time (within 50 s). In a mixed aqueous solution, CM reacts with HSO3− to give a new product 1-(9-butyl-9H-carbazol-3-yl)-2-(4-(2, 2-dicyanovinyl)phenyl)ethane-1-sulfonic acid. The probe exhibits positive solvatofluorochromism with solid state red fluorescence. The restriction of intermolecular rotation of p-styryl conjugated malononitrile unit enhances the typical solid state fluorescence properties. The probe (CM and its corresponding aldehyde CA) also demonstrates a strong solvent dependence yielding blue to green to pink and even red fluorescence in commonly used organic solvents like n-hexane, toluene, diethyl ether (DEE), THF, DCM, Dioxane, CH3CN and MeOH. The chemodosimetric approach of HSO3− selectively takes place at the olefinic carbon exhibiting a prominent chromogenic as well as ratiometric fluorescence change with a 147 nm blue-shift in the fluorescence spectrum. CM can detect HSO3− as low as 1.21 × 10−8 M. Moreover, the CM can be successfully applied to detect intrinsically generated intracellular HSO3− in human peripheral blood mononuclear cells (PBMCs). CM has shown sharp intensities (2628 ± 511.8) when the cells are HSO3− untreated. At green channel (at 486 nm) almost negligible fluorescence intensities are found (423 ± 127.5) for HSO3− untreated samples. However, the green fluorescence (2863 ± 427.5) increases significantly (p < 0.05), and simultaneously the red fluorescence gets significantly (p < 0.05) diminished (515 ± 113.2) after addition of HSO3−. The CM has been effectively utilized for evaluating the bisulfite ions in food samples as well. The concentrations of HSO3− in diluted sugar samples have been determined with the recovery of 97.6–9.12%.

Metal Organic Frameworks as Heterogeneous Catalysts in Olefin Epoxidation and Carbon Dioxide Cycloaddition

Metal–organic frameworks (MOFs) are a family of porous crystalline materials that serve in some cases as versatile platforms for catalysis. In this review, we overview the recent developments about the use of these species as heterogeneous catalysts in olefin epoxidation and carbon dioxide cycloaddition. We report the most important results obtained in this field relating them to the presence of specific organic linkers, metal nodes or clusters and mixed-metal species. Recent advances obtained with MOF nanocomposites were also described. Finally we compare the results and summarize the major insights in specific Tables, outlining the major challenges for this emerging field. This work could promote new research aimed at producing coordination polymers and MOFs able to catalyse a broader range of CO2 consuming reactions.

Ultraviolet photolysis of monochloro-p-benzoquinone (MCBQ) in aqueous solution: Theoretical investigation into the dechlorination

In this work, the UV-induced transformation of monochloro-p-benzoquinone (MCBQ) in aqueous solution has been systematically investigated through quantum chemical calculations. During the UV irradiation at 253.7 nm, the first triplet state of MCBQ (3MCBQ*) was from the intersystem crossing of its first excited singlet state (1MCBQ*). In aqueous solution, the nucleophilic attack of OH− on carbon atoms in 3MCBQ* was the central reaction. The addition of OH− to olefinic carbon atoms was much more kinetically feasible than that to carbonyl carbon atoms, even though the carbonyl carbon atoms were more positively charged. Moreover, OH− preferred to add to the ortho-position of C–Cl bond, where the unchlorinated atom was more negatively charged than the chlorinated one. The UV photolysis of the primary intermediate (HO-CBQ) was not the same as that of MCBQ. The attack of OH− on the para-position of C–Cl bond was the most efficient pathway. The addition of OH− to the chlorinated atom of 3HO-CBQ* was much more efficient than that in the case of 3MCBQ*, which reveals that more UV irradiation may promote the dechlorination. The findings in the present study may be helpful to enrich the understanding of the halobenzoquinones transformation in aqueous solution.

Selective ethylene oligomerization based on Fe-containing metal-organic coordination polymer catalysts

One-dimensional, two-dimensional and three-dimensional Fe-containing metal-organic coordination polymer (1D/2D/3D-Fe-MOCP) catalysts have been solvothermally synthesized and evacuated at different temperatures to give a series of 1D-Fe, 2D-Fe and 3D-Fe catalysts used for ethylene oligomerization performed in slurry batch mode. Their catalytic performances were investigated with the aid of AlEt2Cl cocatalyst, and moderate catalytic activities and high selectivities to low carbon olefins C4, C6, C8, and C10 were observed. Moreover, the oligomerization product distributions differed depending on various factors such as the structural dimension, ligand type, framework flexibility, distances between metal atoms, et al. 1D-Fe catalyst evacuated at 150 °C for 8 hours showed high C8 olefin selectivity up to 94.90% with the catalytic activity of 6.28 × 105 g/mol(Fe)•h•atm. However, 2D-Fe and 3D-Fe catalysts showed relatively low catalytic activity and low selectivity for C8 olefin.

Understanding water mediated proton migration in conversion of π-bond in olefinic carbon atoms into C–N bond to form β-amino adducts

The aza-Michael reactions with a variety of substrates were conducted in water affording the quantitative yields without any external catalyst, which is contrary to that published in literature. A more rational approach to analyze this problem was by conducting this conspicuous reaction with a variety of substrates in water and the results were analyzed using advanced theoretical calculations. Our investigation on the role of water in the reaction proposed a mechanism wherein water plays dual role both as medium as well as catalyst to facilitate the C–N bond formation using powerful tool in its armory, the “H-bonding”. Reactions were conducted in the absence of an external catalyst or co-solvents and, hence, are a greener approach in organic synthesis. The reactions of 15 examples were conducted with a variety of substrates to afford the addition products in the range of 70–95% yield. Theoretical studies on the transition state analysis suggested that it was the assistance of water, through H-bonding, that facilitated the conjugate addition of amine and proton transfer from ammonium ion, which could happen through two equally possible pathways.

Systematic identification and distribution analysis of olefins in FCC slurry oil

In response to the chemical industry's eco-friendly and high-value-added requirements, FCC slurry oil (SO) has been used as a raw material for novel solid carbon materials. As one of the most important chemically active intermediates and products in the FCC process, olefins may have a significant impact on the quality of the carbon materials produced. However, the existence and distribution of olefins have not been discussed. In this paper, olefinic hydrocarbons were first innovatively identified as important compounds that do exist in SO, and their distributions in sub-fractions below 500 °C, classified with the types and carbon numbers, were analyzed. However, there are great limitations for the existing analytical methods in the distribution detection of olefins in the whole fractions of heavy oils. In order to solve this problem, a newly-developed analytical method has been developed. Two different separation techniques were implemented to separate SO into six sub-fractions and eight group compositions, according to boiling point and molecular polarity respectively, before the analysis of olefin distribution for higher accuracy. The proposed method has been further verified by the GC × GC-TOFMS method and proved to have superior reliability. The olefinic carbons in the fraction of 350–400 °C possess the highest content among the detected narrow fractions, up to 1.55%, which decreases gradually with the increase of boiling points, and the first three sub-fractions between 350–470 °C take most of the olefinic carbons in SO, reaching around 74%.