Reactions with Propylene

The spectrum of chemisorbed propylene in the CH and O—H stretching region is shown in Fig. 15. The band at 3593 cm-1 is clearly due to an OH frequency hence, dissociation accompanies propylene adsorption. Careful scrutiny of the region from 1500 to 2000 cm-1 reveals no band assignable to a ZnH band. Since the presence of adsorbed propylene has been found to block out the infrared active hydrogen chemisorption on the ZnO pair sites, we may assume that propylene adsorption occurs as follows  

the hydrocarbon fragment blocks out the zinc half of the active site, and the ZnH band is not observed. 

Five bands are observed in the region near 3000 cm-1 corresponding to C—H stretching vibrations. (The band at 2947 cm-1, which appears as a shoulder in Fig. 15, is seen as a separate peak when the spectrum is observed on an expanded transmission scale.) Detailed identification of these bands will be deferred, but the weak band at 3055 cm-1 suggests that the hydrocarbon fragment is olefinic. 

If the spectrum of adsorbed propylene is observed in the presence of gaseous propylene, additional bands to those shown in Figs. 15 and 16 are observed. These additional bands are due to a more weakly bound form of propylene which is readily removed by a brief evacuation. The salient 

The spectra of C3H6 and C3D6 show that chemisorption of propylene is dissociative, but they fail to identify which carbon-hydrogen bond is broken on adsorption. To this end the spectra of a number of deuterium-labeled propylenes were studied and compared. These results are summarized in abbreviated form in Table VI, which specifies the hydrogen fragment formed on adsorption the fragment was identified as an OH if a band appeared near 3593 cm-1 or as an OD if a band appeared near 2653 cm-1. In those cases where the spectrum changed with time the summary 

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Higher alcohols have more than three carbon atoms. Examples are the dihydric alcohol, ethylene glycol used for antifreeze, brake fluids and as derivatives in resins, paints " " osives, and polyester fibers. Reactions with propylene make propylene glycol, a moistening ag foods and tobacco. 

Carboxvalkvlation of Propylene Oxide. These reagents were also used in a similar carboxyalkylation scheme to prepare methyl 3-hydroxybutyrate by reaction with propylene oxide (Equation 3). This might represent a way to prepare substitute 1,3 diols(48) following reduction of the ester or reactive monomers by pyrolys is/dehydration. 

Two of the reactions calce place in the same reactor in this plant. The formation of the hypochlorous acid (HOCl) from chlorine and water, and the reaction with propylene all occur simultaneously on the left in Figure 11—2. Propylene reacts readily with chlorine to form that unwanted by-product, propylene dichloride. To limit that, the HOCl and HCl are kept very dilute. But as a consequence, the concentration of the propylene leaving the reactor is very low—only 3—5% Ac any higher concentration, a separate phase or second layer in the reactor would form. It would preferentially suck up (dissolve) the propylene and chlorine coming in, leading to runaway dichloride yields. The low concentration levels of the propylene chlorohydrin and the need to recycle so many pounds of material is the reason the process is so energy intensive. It just takes a lot of electricity to pump all that stuff around. 

The 02 ion on MgO does not react with CO or alkanes at 77 K but the EPR signal disappears slowly at room temperature (361). Similarly, on ZnO (390) it reacts only slowly with propylene at room temperature and not with CO, H2, or ethylene. A slow reaction with propylene is also observed for 02 on V2Os/MgO at room temperature (391). Yoshida et al. (392) have studied the reactivity of adsorbed oxygen with olefins on the V20j/Si02 system. Adsorption of propylene destroyed the signal from 02 slowly at room temperature and the reaction products, aldehydes with some acrolein, were desorbed as the temperature was raised to 150°C. More quantitative... 

Materials. Hydroxypropyl lignin (HPL) Organosolv (aqueous ethanol) lignin from aspen, supplied by Repap Technologies Inc. (formerly the Biological Energy Corporation) of Valley Forge, PA, was hydroxypropylated by reaction with propylene oxide in the usual manner (9). This derivative was isolated and purified as described previously (9). 

These results encouraged us to further functionalized the remaining secondary amine groups of the anchored 1 through reaction with propylene oxide. 

Boddy and Robb have also studied the reactions of hydrogen atoms with propylene (11) and with 2-butene and isobutene (12). In all these reactions they observed decomposition of the hot alkyl radicals and also suggested an enhanced abstraction of hydrogen from the parent olefins by the hot radicals. The reaction with propylene appeared to be complicated by the ocurrence of a number of side reactions. One of the isolated products was 4-methyl-l-pentene, indicating the presence of allyl radicals, which the authors postulated to be formed in the reaction... 

Here, the constants KM and ks denote the equilibrium constant for the propylene monomer coordination and the rate constant for the insertion of the coordinated monomer, and L represents a ligand bound to vanadium. Then, the energy diagram of chain propagation reaction with propylene may be visualized as in Fig. 13. The... 

C, appreciable yields of products were not produced until 750°C. Reaction of ethylene with pure CuF2 or CuF2 dissolved in a eutectic melt of alkali and alkaline earth fluorides between 450°C and 700°C yielded vinyl fluoride and HF and Cu metal. A similar reaction with propylene at 400°C yielded 2-fluoropropene [19]. The reaction cycle is shown in equations (7a) and (7b) and the net reaction scheme is shown in equation (7c). 

Although it is known that free radicals add predominantly to the least substituted end of an olefinic double bond there is very little quantitative information on the relative rate of addition at the two positions in asymmetric olefins (Cadogan and Hey, 1954 Cvetanovid, 1963). The rotating cryostat has been used to examine this aspect for the case of the addition of hydrogen atoms to a variety of olefins deposited in a matrix of adamantane. The ratios of the rates of addition are given in Table 7, and for illustration the reaction with propylene is considered below. 

Rhodium and ruthenium complexes of CHIRAPHOS are also useful for the asymmetric hydrogenation of p-keto esters. Dynamic kinetic resolution of racemic 2-acylamino-3-oxobutyrates was performed by hydrogenation using ((5,5)-CHIRAPHOS)RuBr2 (eq 3). The product yields and enantiomeric excesses were dependent upon solvent, ligand, and the ratio of substrate to catalyst. Under optimum conditions a 97 3 mixture of syn and anti p-hydroxy esters was formed, which was converted to o-threonine (85% ee) and D-allothreonine (99% ee) by hydrolysis and reaction with propylene oxide. 

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