Pristine single-walled carbon nanotubes (p-SWNTs) were converted to 4-chlorophenyl-SWNTs 1 via treatment with 4-chlorophenylamine and isoamylnitrite, and subsequently to 4-mercaptophenyl-SWNTs 2 by using sodium ethanethiolate. Products 1 and 2 were characterized by Raman, UV/vis/NIR, TGA, IR, and 1H NMR. We report a COSY 1H NMR of 1, which appears to be the first such spectrum reported for a covalently sidewall-functionalized SWNT.

Investigations of the title reaction, carried out by plotting logs of the relative reaction rates vs IPs, vs HOMOs, and vs LUMOs, reveal multiple nearly parallel lines of correlation with small negative slopes in each. Overall, the natural grouping into monosubstituted and disubstituted alkenes gives better correlations than that obtained by using all alkenes. Comparison with analogous plots for other reactions indicates that the mechanism for this reaction has similarities to that for hydroboration, the major difference being that the lines in the plots for hydroboration have positive slopes, indicating an electrophilic rate-determining step involving the pi electrons, while those for the title reaction have small negative slopes, indicating a nucleophilic rate-determining step. Of the two reaction mechanisms proposed for the title reaction, only one has a nucleophilic attack at the complexed alkene as the rate-determining step, and therefore, this work supports that reaction mechanism.

A new methodology designed to assess the economic value of the scheduling rules for preventive maintenance on a chemical process plant is presented. The methodology is based on the use of a Monte Carlo simulation, which takes into account scenarios that include equipment failure, resources limitations, repair downtime, performance of failed but not repaired equipment due to lack of resources, and some other maintenance rules. The well-known Tennessee Eastman Plant problem is used to illustrate results.

Plots of the logarithms of relative rates of homogeneous catalytic hydrogenation of alkenes (log k(rel) values) by using Wilkinson's catalyst versus their ionization potentials (IPs) and versus their lowest unoccupied molecular orbital energy levels (LUMOs) display good-to-excellent correlations. The correlations indicate that the rate-determining step of this reaction is a nucleophilic addition to the alkene double bond, which is dependent upon both electronic effects and steric effects. This conclusion is in agreement with only two of three previously proposed mechanisms for the reaction, effectively ruling out one in which the rate-determining step involves electrophilic addition to the alkene. Characteristics of the analysis using these correlations are compared and contrasted with other additions to alkenes, such as the Wacker oxidation, to probe patterns in transition state characteristics.

Recommended changes in use of cyclohexane conformers and their nomenclature will remedy inconsistencies in cyclohexane conformers and their nomenclature that exist across currently used organic chemistry textbooks. These inconsistencies prompted this logical analysis and the resulting recommendations. Recommended conformer names are chair, half-chair, twist-boat, and boat. These names are frequently used, although usually combined with additional or alternate names that can confuse students consulting multiple textbooks. The half-chair conformation structure with four coplanar carbons is recommended instead of the structure with five coplanar carbons, because calculations predict it is more stable and lies on the lowest energy pathway for cyclohexane conformer interconversion. Currently, the incorrect structure with five coplanar carbons is most often presented to students. As defined, the recommended names and structures are consistent, descriptive, pedagogically useful, and in agreement with research literature.