Addition compounds, formation

Of somewhat greater technical interest are the addition compounds and the cellulose esters and ethers. Of the apparent addition compounds the most important is alkali cellulose produced by steeping cellulose in caustic soda and considered to be of general form (CgHioOs), (NaOH) ) rather than a sodium alcoholate compound. Alkali cellulose is a particularly important starting point in the manufacture of cellulose ethers. The ability of aqueous cuprammonium hydroxide solutions to dissolve cellulose appears to be dependent on addition compound formation. 

I) The selection of the enthalpy of adduct formation, as an approximation to the change in internal energy of the donor and acceptor upon addition compound formation, results from the thorough discussion by J. E. Leffler and E. Grunwald in Rates and Equilibria of Organic Reactions, New York John Wiley 1963. 

The reaction of sodium with fiuorene is of considerable interest. Fluorene possesses a hydrogen acidic enough that it might be expected to react directly with sodium to form 9-fiuorenylsodium. Fluorene is aromatic enough to be expected to form the sodium addition compound in the presence of the specific ether solvents which promote addition compound formation. 

This reaction was studied in some detail in order to gain some insight into the relative ease with which addition compoimd formation and hydrogen displacement take place (20). It was shown that, under conditions which normally lead to addition compound formation, 9-fiuorenylsodium is formed, but the addition compound is an intermediate. Briefiy, the evidence leading to this conclusion is as follows ... 

Unsaturation may therefore be used as the property upon which the catalysis of these reactions depend. Without entering into the structural formulas of the addition products at present, this property means that addition compound formation of one or all of the reacting substances with the catalyst precedes or accompanies the reactions. D. Klein [Jour. Phys. Chem. 15, 1 (1911)] in studying the relative rates of the reaction between hydrogen sulfide and sulfur dioxide in a number of organic substances. 

Some theoretical relations with regard to catalytic reactions will now be taken up. A simple mechanical analogy developed by Professor J. M. Nelson and Dr. J. H. Northrop, may be of interest here in considering the energy or affinity relationships, although it does not include the view of addition compound formation. 

In looking at this reaction from the point of view of intermediate addition compound formation, it is evident that it belongs to the same group of reactions. The intermediate... 

The theory of reactions in aqueous solutions, heretofore based upon ionization relationships, can be accounted for by addition compound formation involving the solvent. 

Sugar-Bisulfite Addition Compound Formation Rate Constants (fc2) t t... 

Comparative Order of Rate Constants for Bisulfite Addition Compound Formation and Free Aldehyde Appearance for Aldoses... 

Investigation of the effect of substituents on the overall rate of benzaldehyde semicarbazone formation shows that there is a change in rate-determining step with a change in hydrogen ion concentration. At neutraUty, where the overall rate should depend upon both the equiUbrium constant for addition compound formation and the rate constant for its dehydration, the two substituent effects effectively... 

The rates of carbonyl addition reactions are strongly dependent on the steric requirements of the carbonyl compound. Bulky groups near the reaction center will usually stabilize the carbonyl compound relative to the carbinolamine, thereby decreasing the equilibrium j constant for addition compound formation and giving smaller overall rates of product formation. Several workers have investigated the i steric effect of ketones in oxime formation Methyl ketones are... 

The effect of the amine on the overall equilibrium constants of condensation reactions of carbonyl compounds and amines has been discussed above (see section II.A) where it was pointed out that the thermodynamic stability of the C=N— linkage increases with the type of amine used, in the order NH3 < aliphatic amines < aromatie amines < amines containing an adjacent electronegative atom with a free electron pair. In contrast to the overall equilibrium constants, the rate and equilibrium constants for addition compound formation appear to be dependent on the basicity of the amine. In studies in which different amines have been reacted with the same earbonyl compound under the same conditions, the following observations have been made. The equilibrium constants for addition compound formation with -chlorobenzaldehyde were found to be 21 7, 9-11, 4 14 1/mole for hydroxylamine (pJiTa = 6-0) methoxyamine (pA =... 

Kendall J, Booge JE, Andrews JC (1917) Addition compound formation in aqueous solutions. The stability of hydrates and the determination of hydration in solution. J Am Chem Soc 39 2303-2323... 

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