The structural characteristics of a pentane-insoluble asphaltene isolated from the vacuum residue of an Arabian crude mixture have been investigated by pyrolysis gas chromatography/ mass spectrometry (py/GC/MS), 1 H/ 13 C NMR, gel permeation chromatography (GPC), and matrixassisted laser desorption/ionization time-of-flight (MALDI TOF) mass spectrometry. Assignments of NMR signals of the asphaltene have been discussed briefly on the basis of the information from the literature and compared with those of an aliphatic fraction isolated from the ruthenium ion catalyzed oxidation products of the asphaltene. The comparison data indicated that aliphatic substitution 〉C 1 on aromatics are little; however, most of the chain methylene groups are located within a polymeric-saturated fraction of the asphaltene. The average size of aromatic fused ring systems has been determined to be 4-5 for the sample. Pyrolysis tests implied that the asphaltene sample is constructed with relatively large polycyclic units connected by relatively strong bonds. Our results also support a view that asphaltene is the mixture of complex polydispersed molecules with large variation of molecular sizes.

The activated carbons were prepared from Malatya (a city located in the south-east of Turkey) apricot stones by one-step steam pyrolysis/activation process and characterized for their pore structures. Three kinds of apricot stones that differ in their sulfur content, because of the different drying processes, were chosen for this study to investigate the effect of sulfur in the activated carbon production. The effect of process variables, such as activation temperature, soak time, and particle size range was studied on these samples. The activation temperature and time tested were in the ranges of 650-850°C for 1-4 h. The activated carbons were evaluated for their chemical (elemental composition), surface (BET surface area, mercury porosimetry), and adsorption (iodine number) properties. Carbonization behavior of the apricot stones was investigated by thermogravimetric analysis. Scanning electron microscopy (SEM) was used to follow the changes in the carbon texture upon activation.The experimental results revealed that carbons obtained by the same conditions of activation show differences in their pore structures and adsorption characteristics due to their sulfur contents. The highest BET surface area carbon (1092 m 2 /g) was obtained from the low sulfur content (0.04%) apricot stone with a particle size range of 1-3.35 mm at the activation conditions of 800°C for 4 h. The experimental results showed that commercial production of porous activated carbons from Malatya apricot stones is feasible in Turkey.

Information about bridge structure and functionalities has been considered to be crucial in estimating the reactivity of coals, and the purpose of this study is to improve the validity of the RICO technique in the determination of aliphatic bridges and functional groups using a Japanese Taiheiyo coal. It was found that room temperature, which had been commonly employed previously, is insufficient for efficient oxidation kinetics and higher temperature such as 40 °C increased the oxidation kinetics 2-fold. Candidates for the remarkable amounts of resolved aliphatic polycarboxylic acid products are thought to be the corresponding polyaryl-substituted aliphatic cross-linkages and various hydroaromatic species. Remarkable amounts of polymeric aliphatic fraction were also formed after RICO. Much higher amounts of benzenepolycarboxylic acids were recovered, and significant improvement of carbon mass balance was achieved contrary to previous reports.

Pd(0)-catalyzed carbonylation of (Z)-2-en-4-yn carbonates in the presence of a balloon pressure of CO in an alcohol donates vinylallenyl esters with an exclusively E-configuration and in high yields. The fact that no such reactivity could be observed with E-configured enyne carbonates may indicate that the reaction is promoted via the cooperative coordination of palladium with both alkynyl and carbonate moieties. Supporting Information Available. Detailed experimental procedures, and compound characterization data. This material is available free of charge via the Internet at http://pubs.acs.org.

Abstract-The Pd(0)-Y zeolite showed high activity in the Suzuki cross-coupling reactions of aryl bromides without added ligands. The type of base and organic solvent were found to be critical for the efficiency of the reaction. The presence of water was essential within the reaction medium. The coupling reactions occurred on the external surface of the zeolite. The catalyst is reusable.

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The structure of Chinese bituminous Zao Zhuang coal was carefully evaluated on the basis of information from NMR, pyrolysis, ruthenium-catalyzed oxidation reaction (RICO), and single coal particle solvent swelling methods. This coal and its SRC liquefaction fractions show good coking property so that the pyrolysis is accompanied by a lot of coke, this being less useful for its structural elucidation than the case of Japanese Akabira coal. The pretreatment of this coal by the ether bond cleavage reaction can increase volatile-comprising molecules that when recognized provide valuable information on molecular constituents of the coal. SPE/MAS 13 C NMR and CP-DD (dipolar dephasing)/MAS 13 C NMR techniques were used to assess carbon distribution. The RICO reaction offered information regarding aliphatic functionalities and bridge types and also suggested the presence of some types of molecular units. Solvent swelling experiments implied that this coal has, on average, relatively low cross-link density and verified the structural heterogeneity of the coal. By using the data from the analytical techniques given above, a model structure of Zao Zhuang coal consisting of one MS, one PS, and two PI structures was constructed. The proposed structure is in keeping with various aspects of its reactivity.

Ruthenium-ion-catalyzed oxidation (RICO) was used to investigate the structural details of an asphaltene sample. The oxidation products consisted of homologous series of straight-and branched-chain monocarboxylic acids, dominated by C 2 -C 4 acids. Aliphatic di-and polycarboxylic acids were also resolved, confirming the presence of polymethylene moieties linking two or more aromatic units. The detection of ethanedioic acid among the oxidation products indicates the importance of biaryl linkages within the asphaltene. Large amounts of a polymeric aliphatic fraction were also recovered after RICO reaction. The recovery of benzene polycarboxylic acids and a high molecular weight aromatic acid fraction, along with NMR analyses of the original asphaltene, indicates that the asphaltene molecule is comprised of relatively large polycondensed aromatics and hydroaromatic units.