The acidities of some mineral acids in acetic acid; The acidity function (H0)I

1957 ◽  
Vol 22 (1) ◽  
pp. 1-13 ◽  
Author(s):  
J. Roček
1971 ◽  
Vol 49 (18) ◽  
pp. 2964-2976 ◽  
Author(s):  
Eberhard Kiehlmann ◽  
Pui-Wah Loo ◽  
B. C. Menon ◽  
Nora McGillivray

Strong mineral acids convert 1,1,1-trichloro-2-hydroxy-4-alkanones to 1,1,1-trichloro-2-aIken-4-ones and 1,1,5-trichloro-1-alken-4-ones via an intramolecular chlorine shift from C-1 to −5 of an enol allylic system. Alternatively, 1,1,1-trichloro-2-alken-4-ones may be synthesized from 1,1,1-trichloro-2-hydroxy-4-alkanones by acetylation and elimination of acetic acid or by nucleophilic substitution with thionyl chloride followed by dehydrohalogenation. The two diastereomeric 1,1,1-trichloro-2-hydroxy-3-methyl-4-hexanones do not epimerize during acetylation, and the erythro-acetate resists elimination of acetic acid. Pyrolysis of 2-(1-hydroxy-2,2,2-trichloroethyl-)cyclohexanone yields 2-(2,2-dichlorovinyl)-2-cyclohexenone while treatment of 1,1,1,7,7,7-hexachloro-2,6-dihydroxy-4-heptanone with strong acid leads to the formation of 1,1,1,7,7,7-hexachloro-2,5-heptadien-4-one.


1954 ◽  
Vol 76 (14) ◽  
pp. 3853-3854 ◽  
Author(s):  
Frederick J. Ludwig ◽  
Kenneth H. Adams

1966 ◽  
Vol 44 (16) ◽  
pp. 1899-1916 ◽  
Author(s):  
J. F. Bunnett ◽  
Fredric P. Olsen

Linear relationships exist between the logarithms of equilibrium quotients, [SH+]/[S][H+], of diverse bases as they vary with acid concentration in moderately concentrated mineral acids. For purposes of formulating these linear free energy relationships in standard form, the equilibrium quotient for protonation of a hypothetical aromatic primary amine of pKa zero has been chosen as horizontal coordinate; this is given by (−H0 − log [H+]). Log ([SH+]/[S]) + H0 is plotted against (H0 + log [H+]). The slope, [Formula: see text] of the linear plot is a parameter which characterizes the response of the equilibrium quotient to changing acid concentration. The intercept represents the thermodynamic pKa of the base. This constitutes a general method for estimating the pKa of any base which undergoes protonation in moderately concentrated mineral acid, with reference to the single acidity function, H0. For bases of diverse type, pK's estimated by this method are in good agreement with those estimated by the acidity function method. Use of the new correlation procedure as a check on the validity of several acidity functions and its application to equilibria not involving proton gain or loss are also discussed.


1999 ◽  
Vol 64 (9) ◽  
pp. 533-538
Author(s):  
D.S. Veselinovic ◽  
M.V. Obradovic ◽  
S.B. Tosic

The absorption spectra of monohydroxybenzene (Fen), 1,3-dihydroxybenzene (Rez), 1,4-dihydroxybenzene (Hi), 1,2,3-trihydroxybenzene (Pg) and 1,3,5-trihydroxy-benzene (Fg) in aqueous solutions of hydrochloric acid with different values of the Hammett acidity function(H0) have two absorption bands in the region between 190-220 nm and 260-290 nm. This behavior is similar in another mineral acids (H2SO4, H3PO4, HClO4). The absorbance decreases with increasing of acidity (with decreasing of H0 values) because of O-protonation. The absorption maxima shift to longer wave-lengths, and the graphic dependence of the absorption of the second band as a function of H0 gives characteristic S-curves. These curves show the different effect of the acid on the form the protonation of the investigated hydroxybenzenes. The potonation constants of the hydroxybenzenes were calculated: pKFen=-1.95; pKRez=-2.40; pKHi= -1.93; pKPg=-2.95; pKFg=-1.83.


1940 ◽  
Vol 11 (3) ◽  
pp. 243-265 ◽  
Author(s):  
A. Cunningham ◽  
A. M. Smith

1. The microflora of A.I.V. silage consists mainly of lactic acid bacteria—lactobacilli, streptococci, micrococci and sarcinae. Some samples also contain yeasts and yeast-like organisms.2. Among the lactobacilli, both homo- and heterofermentative types are represented. The former include strains ofLactobacillus plantarum(Orla- Jensen) Bergey et. al.; in the heterofermentative groupL. brevis(Orla-Jensen) Bergey et al. has been found.3. Cultures of a motile homofermentative lactobacillus were isolated; this appears to be a new type. Among the unidentified heterofermentative lactobacilli, forms which may prove to be similar to the inactive group of Pederson were encountered.4. The homofermentative streptococci were found to belong to the Streptococcus lactis group; the heterofermentative forms were identified withLeuconostoc mesenteroides(Cienkowski) van Tieghem.5. Strains of unidentified homofermentative micrococci and sarcinae were isolated and shown to possess characteristics not usually associated with organisms of these types.6. Streptococci, micrococci and motile lactobacilli were found mainly in fodder recently ensiled; the majority of the lactobacilli and sarcinae were associated with the older samples.7. The characteristics which proved to be most valuable for the differentiations of the organisms were ability to produce carbon dioxide, percentage of lactic acid formed and lactic-acetic acid ratio.


The chemotherapeutic action of compounds of bismuth in spirochætal infections was observed by Robert and Sauton. These workers found that sodium bismuthyl tartrate had a marked effect in preventing and curing infection with Spirochæta gallinarum (Fowl Spirillosis). Since then the action of compounds of bismuth has been extensively investigated in spirochætal infections (see Levaditi). The present work concerns the bismuth derivatives of organic hydroxy-acids. All the compounds investigated are white amorphous solids, of which only the derivatives of the monobasic sugar acids are at all soluble in water. They are stable to acetic acid, but are instantly decomposed by dilute mineral acids; and; with the exception of the citric acid and ester com­pounds, are soluble in alkali. The therapeutic action of these compounds was tested in the case of mice infected with Sp. laverani (Breinl and Kinghorn; Sp. muris of Wenyon). Infections with the strain used, which was non-pathogenic for mice, had the following characteristics:—As a rule, five or six days after subcutaneous in­ oculation with a suspension in saline of infected blood, the organisms were found in the peripheral circulation in small numbers. Thereafter they usually became more numerous and persisted for long periods. Their abundance in the blood appeared to vary from time to time and after some months they might become very scanty. The value of this infection as a test for chemotherapeutic pro­perties lies in the fact that it is susceptible to agents such as salvarsan, which are effective in the treatment of infections with Tr. pallidum .


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