2-Butanol, catalytic decomposition

The proposed catalytic cycle is shown in Fig. 8.5. A variety of molybdenum compounds may be used as the precatalyst, and Mo(CO)6 is shown as a representative one. Under the strong oxidizing conditions the precatalyst is oxidized to 8.21, a species that has molybdenum in a 6+ oxidation state and a di-MoOf unit. The other ligands are two solvent molecules and hydroxo and/ or alkoxo groups. In the absence of a solvent, positions occupied by S are occupied by /-butanol, the decomposition product of /-butyl hydroperoxide. The important points to note are that molybdenum is in its highest oxidation state (6+), and there are weakly bound solvent molecules. 

Several catalytic test reactions have been used for indirect characterization of acid and base properties of solids (78). Among them, decomposition of alcohols such as 2-propanol (79,80), 2-methyl-3-butyn-2-ol (81,82), 2-methyl-2-butanol (83), cyclo-hexanol (84), phenyl ethanol (55), and t-butyl alcohol (86) have been investigated. In... 

Terent yev A.P. and Klabunovskii E.I. (1953) Catal54ic asymmetric synthesis. I. Asymmertric decomposition of racemic 2-butanol over Cu-quartz catalysts. Comm. I., in Collection of papers on General Chemistry russ.), V.2, 1521-1529 Chem. Abstr. 1955,49,5262E Terent yev A.P. and Klabunovskii E.I. (1953) Catalytic asymmetric synthesis. Comm. II. Asymmetric decomposition of 2-butanol over quartz-catalysts, in Collection of papers on General Chemistry (russ.)y.2, 1598-1604 Chem. Abstr. 1955,49, 5262g. 

Method c) is exemplified in the chiral modification of surfaces of zeolites with chiral compounds. Sundarababu et al. modified NaX and NaY zeolites with (-)-ephedrine and used them in the asymmetric photolysis of ketones with ee s above 10%. A strange behavior of the nature of carriers for the configuration of products in the latter reaction was observed the NaY-(-)-ephedrine zeolite system gave (+)-rotating products, while the NaX-(-)-ephedrine zeolite system gave (-)-rotating products. Zeolite H-Y modified with R)- or (5)-dithiane-l-oxide showed catalytic activity in the asymmetric decomposition of racemic 2-butanol (Hutchings)... 

This study describes two methods to prepare well-ordered adipate-pillared hydrotalcite-like LDHs. One is the ion-exchange method, the other is the coprecipitation method. The former has not been reported before. As to the latter, products with diffuse or amorphous X-ray patterns were previously observed (Drezdzon 1988 Reichle 1985). These organic-pillared LDHs served as precursors and were ion-exchanged with tetraborate ions. The resultant pillared hydrotalcite-like LDHs had fairly good crystallinity. This is ascribed to tetraborate anions being stable under mildly basic conditions. The variables in preparation conditions which might influence the pillared products were examined. The catalytic activity of the pillared material in 2-butanol decomposition reaction was also discussed. 

Table 8-1 The catalytic activities of hydrotalcite-like materials in 2-butanol decomposition. 

The acidic and basic properties are dependent upon the preparation and activation methods. Thorium oxide is usually prepared from aqueous solution of thorium nitrate or chloride by precipitation with aqueous ammonia followed by washing, and calcining. In some cases, Th02 is prepared by thermal decomposition of thorium nitrate or thorium oxalate. The acidic and basic properties of the Th02 prepared from ThCU are distinctly different from the other Th02. The catalytic activities of Th02 prepared by different methods for 1-butene isomerizaton and 2-butanol dehydration are summarized in Table 3.5.The ThOz prepared from cholride completely lacks the measur-... 

The reaction of 2-butanol over tin (IV) oxide at 573 K gives only methyl ethyl ketone, a dehydrogenation product butenes, dehydration products, are not formed. Tin oxides have catalytic activities for the decomposition of diacetone alcohol at 303 K S3) jjjgjg indicate that tin (IV) oxide is a basic rather than an acidic oxide. 

Others The binary oxide Z1O2 —SnOz has both acid and base sites. The maximum strength of the acid sites is observed to be Ha= —3.0 at the composition ZrOz 90%. The acid sites on oxides of other compositions are weaker than ifo=1.5. The number of base sites on the binary oxide is less than on the component oxide ZrOz- The catalytic activities for cyclopropane ring opening and 2-butanol dehydration correlate with the acidity, while those for 1-butene isomerization and diacetone alcohol decomposition correlate with basicity. 

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