Monoacidic base

GHC13). It is readily soluble in alcohol, chloroform or benzene, less so in ther, and almost insoluble in cold water, but sparingly so in ammonia or me-water. Thebaine behaves as a monoacidic base. The hydrochloride,... 

Harmine, C13H12ON2, crystallises from methyl alcohol in colourless rhombic prisms, m.p, 266°, [a]D 0°. The hydrochloride, m.p. 269-5-270-5° (Chen ), nitrate, platinichloride, m.p. 264-6°, acid chromate and oxalate crystallise well. The salts show a deep blue fluorescence in dilute solution. Harmine behaves as a monoacidic base. It gives a methiodide, from which methylharmine, needles, m.p. 209°, may be prepared, and this in turn yields methylharmine methiodide. On demethylation harmine yields the phenolic base harmol, C12H10ON2, m.p. 321°.i ... 

Brucine is a monoacidic base the salts crystallise well and are readily soluble in water. The hydrochloride, B. HCl, forms needles, the hydriodide, B. HI, leaflets, sparingly soluble in water and the sulphate, B2. H2SO4.7H2O, long needles. 

Strychninic Acids fStrychnic Acids). Although strychnine contains two atoms of nitrogen, it behaves as a monoacidic base. Warmed with a solution of sodium ethoxide it takes up a molecule of water, forming strychninic acid, which crystallises in minute needles, m.p. 215°,... 

HjO) and Bj. H2SO4.4HjO, m.p. 203-4°, [a] ° + 120° the acid sulphate, B. HjSO, occurs in yellow prismatic needles, m.p. 246-8° (corr., dec.), [a]n + 113-1° (HjO) the hydrochloride forms yellow, pentagonal plates, m.p. 286° (corr., dec.), and shows a purple fluorescence in solution in alcohol the picrate separates from alcohol in rosettes of reddish-orange needles, m.p. 194-5° (cort.). Dilute solutions of the salts are yellow and show a marked blue fluorescence. Alstonine behaves as a monoacidic base, contains one methoxyl but no methylimino group, and, unlike echitamine, does not give indole colour reactions. 

An inflection point in a pH-rate profile suggests a change in the nature of the reaction caused by a change in the pH of the medium. The usual reason for this behavior is an acid-base equilibrium of a reactant. Here we consider the simplest such system, in which the substrate is a monobasic acid (or monoacidic base). It is pertinent to consider the mathematical nature of the acid-base equilibrium. Let HS represent a weak acid. (The charge type is irrelevant.) The acid dissociation constant, = [H ][S ]/[HS], is taken to be appropriate to the conditions (temperature, ionic strength, solvent) of the kinetic experiments. The fractions of solute in the conjugate acid and base forms are given by... 

Buffer mixtures are not confined to mixtures of monoprotic acids or monoacid bases and their salts. We may employ a mixture of salts of a polyprotic acid, e.g. NaH2P04 and Na2HP04. The salt NaH2P04 is completely dissociated ... 

The acidity of a base is the number of hydroxy ions formed per molecule of the base in aqueous solution. It may also be considered as the number of H+ ions that can be accepted by one molecule of the base. Thus, NaOH and KOH are monoacid bases, Ca(OH)2 and Mg(OH)2 are diacid bases, and Al(OH)3 and Fe(OH)3 are triacid bases. 

Guanidine is a strong monoacid base, indistinguishable from potassium hydroxide in an electrometric titration. There is considerable evidence 5 which indicates that the charge of the guani-donium ion resides upon its carbon atom. 

Andronati and co-workers reported a detailed study of the A-basicity of compounds 203 (X = H, Me R1 = H R2 = H, Br, Cl, Me) which contain amide, imine, and amine nitrogens in one molecule. The basicities, obtained from the half-neutralization potentials in potentiometric titrations, showed 203 to be monoacidic bases the basicity varied predictably with substitution and fell between the stronger quinoxaline-2-ones and the weaker l,4-benzodiazepine-2-ones. Ultraviolet spectroscopic studies demonstrated that the amino, not the imino, nitrogen was N-protonated (83CHE337). 

Uncarine-A and formosanine are monoacidic bases, which contain one... 

Gelsemicine, C20H26N2O4, mp 171°-172°, [a]D-142°, is a monoacidic base, which contains one C -methyl and two methoxyl groups (14,16,18) the presence of a methylimino group, reported earlier, has since been shown to be erroneous. The UV-spectrum of gelsemicine has a comparatively unfamiliar appearance and it is difficult to deduce the nature of the chromophore present. The spectrum shows some resemblance to those of 7-methoxyindole derivatives, although it does not possess a pronounced minimum at 250-260 mp. in neutral solution (18, 100). In alkaline solution, the curve is more like that expected for a substituted indole derivative. 

If a is the initial concentration (molality) of the weak or moderately weak acid HA, and h is the amount of strong, monoacid base MOH added at any instant, then h is also equal to mM > the molality of ions at that instant, since the salt MA produced on neutralization may be taken as being completely dissociated. The acid HA is only partially neutralized to form A ions, and so... 

If to a solution containing the acid H2A at molality a there are added b equivalents of a strong monoacid base, MOH, the solution will contain H+, M+, HA , A— and OH ions for electrical neutrality therefore,... 

Approximate Methods for Dissociation Constants.—Approximate, but more rapid, methods, similar to those used for simple monobasic acids and monoacid bases, have been frequently employed to determine dissociation constants of ampholytes. Upon taking logarithms, the equation for Ki may be written as... 

For all monobasic acids (HCl), monoacid bases (NaOH), and their salts, i is nearly equal to 2, for dibasic acids and their salts approximately 3. 

For monobasic acids and monoacid bases and their salts, we have w = 2, and hence... 

Morphine is a monoacidic base and readily forms wain-soluble. salts with most acids. Thu.s. becau.se murpliinc ilsck is so poorly. soluble in water, the salts are the preferred fomi for most uses. Numerous salts have been marketed, but ih ones in use are principally the. sulfate and. to a lesser e.ueni. the hydrochloride. 

It iK dirs as levorotatory. colorless, efflorescent crystals orasawhitc crystalline powder. It is light sensitive. Codeine U slightly soluble in water (1 120) and sparingly soluble in ether (1 50). It is freely soluble in alcohol (1 2) and very soluble in chloroform (1 0.5). Codeine is a monoacidic base and readily forms salts with acids, with the most important being the sulfate and the phosphate. The acetate and methyl-bntniide derivatives have been used to a limited extent in tough preparations. 

The formation of salts with melamine (1.3,5-triazine-2,4,6-triamine) is the most extensively studied reaction of this type. In most cases, melamine acts as a monoacidic base and forms salts with mineral acids, e.g. hydrochloric acid, nitric acid or sulfuric acid, inorganic complexes, e.g. hydrogen tetrachloroaurate(III) or dihydrogen hexachloroplatinate(IV) and a large variety of organic acids, e.g. acetic acid, oxalic acid, picric acid or some sulfonic acids.30... 

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