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The catalytic asymmetric hydrogenations of α-diketones, α-keto carboxylates, α-(acylamino)acrylates, α-phenylacrylophenone, and α-phenylacrylate were examined with bis(dimethylglyoximato)cobalt(II)–chiral cocatalyst (amino alcohol) and with simple achiral base coordinated bis(dimethylglyoximato)cobalt(II)–chiral cocatalyst (amino alcohol) systems. These gave corresponding optically active reduction products, and in some cases, optically active reductive dimerization products. High degrees of enantioselectivities (≈78%) are achieved in the hydrogenation of α-diketones. Evidence for non-binding of chiral base to cobalt complexes was presented in the case of latter system, i.e., it was shown that the catalytic site and the enantioselectivity-determining site are separated in this system, as in enzymes. The importance of protonated chiral bases for enantioselection was also shown. Based on these results and the stereochemical correlations between structures of the chiral bases and those of the products, a mechanism for this asymmetric hydrogenation was proposed.

Cokes formed at several locations in vinyl chloride monomer (VCM) manufacturing have been examined by chemical analysis, scanning electron microscopy/energy-dispersive X-ray spectroscopy (SEM/EDX), X-ray powder diffraction, Mössbauer spectroscopy, and diffuse reflectance infrared. Based on SEM micrographs, visual inspection, and chemical analysis, it appears that coke is formed by tar droplet formation in the cracking furnace and subsequent condensation and impingement on the pipe wall surfaces. Results suggest that coke is formed by a different mechanism in the 1,2-dichloroethane boiler. SEM results did not reveal the presence of filamentous coke, suggesting that surface metal-catalyzed coke formation via metal carbide intermediates does not occur. Metal surfaces become chlorided which may inhibit coke formation via carbide intermediates. Chemical analysis shows the presence of metals (Fe, Cr, and Ni), predominantly iron, throughout the coke samples. Mössbauer data indicate that iron is primarily present as FeCl2. Chlorine is also present throughout the carbon phase of the cokes. The pattern of distribution of iron through the plant suggests that iron present in the coke samples comes from FeCl2 in the gas phase. Infrared spectra indicate that the cokes have a distinct chemical composition depending on their location in the plant.

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