Ketones correlation table

IR interpretation can be as simple or as complicated as you d like to make it. You ve already seen how to distinguish alcohols from ketones by correlation of the positions and intensities of various peaks in your spectrum with positions listed in IR tables or correlation tables. This is a fairly standard procedure and is probably covered very well in your textbook. The things that are not in your text are... 

If X is a carbon-carbon unsaturated bond (and inductive effects are virtually absent) the contribution of (c) to the mesomeric hybrid is greatly increased, and this results in the carbonyl bond having less double bond character, with a consequent decrease in the frequency of absorption. Inspection of the correlation tables (Appendix 2, Table A2.8) clearly shows the effect of such conjugation in oc,/ -unsaturated aldehydes and ketones, and aromatic aldehydes and ketones. 

The expected change in Bronsted exponent with change in reactivity is illustrated by the results [49] shown in Table 9 for the hydrolysis of vinyl ethers (mono alkoxy-activated olefins) which occurs by initial slow protonation of olefinic carbon as in mechanism (28). The value of R which is the catalytic coefficient for an acid of pK 4.0 calculated from results for carboxylic acids with pK around 4.0 is taken as a measure of the reactivity of the system. The correlation of a with reactivity is scattered but the trend is in the expected direction. The results are quite similar to those shown for the ionization of ketones in Table 2. For the proton transfers shown in Table 9 the Bronsted exponent has not reached the limiting value of zero or unity even when reaction in one direction is very strongly thermodynamically favourable. The rate coefficient in the favourable direction is probably well below the diffusion limit, although this cannot be checked for the vinyl ethers. Non-limiting values for the Bronsted exponent have also been measured in the hydrolysis of other vinyl ethers [176]. 

It is important to point out at this point that the rate constant k and the quantum yield for a photochemical reaction are not fundamentally related. Since the quantum yield depends upon relative rates, the reactivity may be very high (large kr), but if other processes are competing with larger rates, the quantum yield efficiency of the reaction will be very small. That there is no direct correlation between the quantum yield and the rate is clearly seen from the data in Table 1.2 for the photoreduction of some substituted aromatic ketones in isopropanol ... 

The validity of this approximation is best illustrated by the results offered in Table 16.5. Although Eq. (16.4) permits accurate calculations of atomization energies and represents a simple and valuable tool, it must be made clear that the charge-NMR shift correlations used for the atoms of the carbonyl group (i.e., those involved in the A j Sca and A460 terms) are empirical. On the other hand, it turns out that for the ketones A j 8ca +A460 amounts to less than 5% of kAqk- Hence, with... 

The results in Table V support this ground state electron distribution effect. The data in italics show that the relative quantum yields are CN < Cl < CH3 with respect to the electron-donating substituent X, and CN > Cl > CH3 with respect to electron-withdrawing substituent Y. Unfortunately, the different quantities in which the quantum yields are expressed and the different reaction media do not allow a direct comparison of the results. Kobsa s data29 on ortAo-hydroxyphenyl ketone formation in the first column can be correlated with Hammett s a constants (Eq. 1, the fraction is proportional to the quantum yield). 

As shown in Table XVI, TA-NaBr-MRNi catalyzed the enantio-differentiating hydrogenation of ketones with a much higher EDA than TA-MRNi. The increase of EDA of TA-MRNi with NaBr for each substrate can be correlated with the hydrogenation rates of each substrate at the modified surface and the unmodified surface. 

The results of these experiments are summarized in Table V, which shows values of A0/A and Z for the ketone copolymer films. All of the polymers in the first section underwent significant damage and were very brittle. However, there was not much attenuation in the first section as indicated by the similar Z values of the PS-MIPK films placed at the beginning and the end of the section. It should be pointed out that the errors in determination of Mn by GPC are substantial — considerably greater than the FTIR measurements. Nevertheless, the Z values correlate quite well with A0/A, indicating the importance of the Norrish type I process in causing chain scission. 

Such correlation equations have been derived for many classes of compounds (Table 7.3). These examples illustrate that very good relationships are found when only members of a specific compound class are included in the LFER. One can also reasonably combine compound classes into a single LFER if only compounds that exhibit similar intermolecular interaction characteristics are used (e.g., alkyl and chlorobenzenes aliphatic ethers and ketones polychlorinated biphenyls and polychlorinated dibenzodioxins). 

Another physical study which used flash photolysis relates directly on the MB/amine system. Kayser and Young (36) examined a more extensive series of amines, both aromatic and aliphatic, than Steiner (33). Their results are shown in Table 3. Excellent correlation was obtained between the amine ionization potential and the rate constant for MB quenching the slope of the logarithmic plot was -1.75 eV-1- This value is relatively small compared to some oxidizing excited states (e.g. hydrocarbons, -17 eV l (37)), but it is similar to the value observed for ketone triplet quenching by amines (-1.5 eV l (38)), and does indicate that the quenching interaction becomes more facile as... 

TABLE 6. The correlation of predicted and observed n — n Cotton effects with the sign of the a,/3-unsaturated ketone torsion angle13... 

When we applied ketones. J-iX to Silicalite using the inclusion technique described earlier we observed phosphorescence in only a few examples, see Table I. Elemental analysis of the samples revealed a clear correlation between their carbon content and the relative phosphorescent intensity. The behaviour observed can be adequately analyzed by separating the ketones in three main groups ... 

In later discussion on the correlation of entropies of activation and reaction mechanism, we shall be particularly concerned with reactions in aqueous solution. Particularly germane in this respect is a recent study by Bell and McDougall (1960) on the hydration of ketones and aldehydes (Table 6). The reaction,... 

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