Hydrogenolytic behavior

Asymmetric diarylmethanes, hydrogenolytic behaviors, 29 229-270, 247-252 catalytic hydrogenolysis, 29 243-258 kinetics and scheme, 29 252-258 M0O3-AI2O3 catalyst, 29 259-269 relative reactivity, 29 255-257 schematic model, 29 254 Asymmetric hydrogenations, 42 490-491 Asymmetric synthesis, 25 82, 83 examples of, 25 82 Asymmetry factor, 42 123-124 Atom-by-species matrix, 32 302-303, 318-319 Atomic absorption, 27 317 Atomic catalytic activities of sites, 34 183 Atomic displacements, induced by adsorption, 21 212, 213 Atomic rate or reaction definition, 36 72-73 structure sensitivity and, 36 86-87 Atomic species, see also specific elements adsorbed... 

Initial research centered on the hydrogenolytic behavior of asymmetrically methyl-substituted diarylmethanes (hereafter abbreviated as asym DAMs) on C0O-M0O3-AI2O3 catalyst. 

Subsequently, the hydrogenolytic behavior of 2,5,3 -trimethyldiphenyl-methane (2,5,3 -TrMeDPM) was investigated as a function of the pretreatment of M0O3-AI2O3 catalyst. 

The relation between the structures of asym DAMs and (a) their hydrogenolytic behaviors and (b) their overall rates of hydrogenolysis. 

The relationship between the hydrogenolytic behavior of an asym DAM and the variations of the catalytic properties. 

HYDROGENOLYTIC BEHAVIORS OF ASYMMETRIC DIARYLMETHANES 237 TABLE I Continued)... 

The product selectivity was assumed to be markedly different as explained in Section I. The relations between the structures of asym DAMs and their hydrogenolytic behaviors, as well as their reactivities, are the next point for discussion. In our studies, a fixed catalyst was used in order to maintain the same effect on the hydrogenolysis of asym DAMs (53). 

Now for an explanation of the hydrogenolytic behavior of phenylaryl-methane, in which only one benzene ring has methyl groups. In the reaction of 4-MeDPM, the molar ratio of toluene and p-xylene was found to be 3.56 1 from the distribution of the reaction products. From this ratio it... 

The hydrogenolytic behaviors of a series of phenylarylmethanes are summarized in Table IV. 

These y and 8 will be the effect of the aryl group on the hydrogenolytic behavior. For example, 2,5,2 -TrMeDPM will be constituted from 2-MeDPM and 2,5-DMeDPM. When the value for the phenyl side is taken as 1, the value of the tolyl side becomes 4.88 (y), using the value obtained experimentally. In the same manner, that of a xylyl group becomes 7.33 ( ). 

The hydrogenolytic behavior of asym DAM can be estimated fairly well from two corresponding phenylarylmethanes. This suggests that the hydro-... 

A catalyst with different properties can be obtained by changing the treatment conditions of the catalyst. The relationships between the hydrogenolytic behavior and the treatment conditions of a catalyst are discussed here in order to clarify the interaction between an asym DAM and the catalyst. A M0O3-AI2O3 catalyst was selected because it is the most selective catalyst for the dearylation of asym DAM as shown in Table II (S4). 

The effects of calcination temperature on the hydrogenolytic behaviors are shown in Fig. 4. The activity increases as the calcination temperature is increased up to 600°C. Then, the conversion is constant until the temperature reaches 750°C, whereupon it drops rapidly. The values of bja indicate almost the same tendency as the conversion. However, the degree of demeth-ylation is almost constant for all calcination temperatures and a(T/TrMeB) = 1.02, j8 = 2.8-4.7%. The increase of conversion by calcination at temperatures... 

Fig. 4. Elfect of calcination temperature on conversion and hydrogenolytic behaviors catalyst 10 wt % M0O3-AI2O3 reduced at 450°C for 2 hr after calcination reaction temperature, 350°C WjF, 7.9 g catal hr mole , H2/(2,5,3 TrMeDPM -(- benzene) molar ratio, 2.0 total pressure, 1 atm.

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