Polyamines basicity

Anion exchange resins- —gel type—weakly basic—polyamine functionality ... 

By virtue of their unique combination of reactivity and basicity, the polyamines react with, or cataly2e the reaction of, many chemicals, sometimes rapidly and usually exothermically. Some reactions may produce derivatives that ate explosives (eg, ethylenedinitrarnine). The amines can cataly2e a mnaway reaction with other compounds (eg, maleic anhydride, ethylene oxide, acrolein, and acrylates), sometimes resulting in an explosion. 

Polyalkylene polyamines find use in a wide variety of appHcations by virtue of their unique combination of reactivity, basicity, and surface activity. With a few significant exceptions, they ate used predominantly as intermediates in the production of functional products. End-use profiles for the various ethyleneamines ate given in Table 6. 

Vulcanisation can be effected by diamines, polyamines and lead compounds such as lead oxides and basic lead phosphite. The homopolymer vulcanisate is similar to butyl rubber in such characteristics as low air permeability, low resilience, excellent ozone resistance, good heat resistance and good weathering resistance. In addition the polyepichlorohydrins have good flame resistance. The copolymers have more resilience and lower brittle points but air impermeability and oil resistance are not so good. The inclusion of allyl glycidyl ether in the polymerisation recipe produces a sulphur-curable elastomer primarily of interest because of its better resistance to sour gas than conventional epichlorhydrin rubbers. 

Macrocyclic polyamines may be viewed as an extended form of linear polyamines 13-161 with one less degree of saturation. Polyamines with lower degrees of saturation, have important biological functions. Compounds such as macrocyclic polyimines 171 and porphyrines 18), function as 02 carriers and activators, promote photosynthesis, form the basic structure of vitamine B12, etc., and for these reasons have been subjects of intense investigation. 

The characteristic property distinguishing macrocyclic polyamines from their linear counterparts is seen in successive protonation. One is the higher N basicity to the first proton and another is a sudden drop of N basicities in the later stages of protonation. Table 1 lists the protonation constants (Eq. 1) for the macrocyclic polyamines in comparison with the corresponding values for their linear homologues. When a linear triamine (e.g. dien) 36,37) is cyclized to, say, (9)aneN3, the basicity of the first amine increases (log Kt = 10.59 us 9.70), but the basicity of the second and especially the third amine diminish (log K2 = 6.88 vs 8.95, log K3 < 1 vs 4.25)36)... 

Amines are ammonia derivatives in which one or more hydrogen atoms have been replaced by an organic radical. Amines are sometimes called nitrogen bases. Basic chemistries include fatty amines (as primary, secondary, tertiary, and polyamines), amine salts, quaternary ammonium compounds, amine oxides, and amides. 

Villanueva, V. R. and Adlakha, R., Automated analysis of common basic amino acids, mono-, di-, and polyamine phenolic amines, and indoleamines in crude biological samples, Anal. Biochem., 91, 264, 1978. 

While the basic and or applied chemistry of saturated macrocyclic polyamines, typically represented by 1,4,7,10-tetraazacyclododecane (cyclen, 1) and 1,4,8,11-tetraazacyclotetradecane (cyclam, 2), have both... 

These are the most common diazeniumdiolates, formed by the reaction of secondary amines and polyamines with nitric oxide in basic media [214, 215]. They are stable solids, capable of regenerating two equivalents of nitric oxide along with the starting amine in neutral or acidic buffers. The half-life of NO generation varies from a few seconds to many hours, depending on the amine. The decomposition to NO is a spontaneous, first-order reaction at constant pH. 

Of the primary monoamines, some, such as. aniline, o-toluidine, xylidine, are colourless liquids. Others, such as p-toluidine, pseudo-cumidine and the naphthylamines, are solids. They can be distilled without decomposition and are volatile with steam. In water they are rather sparingly soluble—a 3 per cent solution of aniline can be made. The di- and polyamines are usually solids, not volatile in steam and much more soluble in water than the monoamines. The amines are basic in character, but, as a result of the negative nature of the phenyl-group, the aromatic amines are considerably weaker bases than are the aliphatic amines. Consequently aqueous solutions of the (stoicheio-metrically) neutral aniline salts are acid to litmus because of the hydrolysis which they undergo. For the same reason a small amount of the free base can be extracted with ether from an aqueous solution of an aniline salt. (Test with a solution of hydrogen chloride in ether or, after evaporation of the ether, by the reaction with bleaching powder.)... 

While all strain effects in monoamines are basicity weakening, it is possible to find cases in di- and polyamines where strain is relieved upon protonation, leading to increased basicity. This phenomenon is observed in 1,4-diaminobutane derivatives where an almost linear N... H—(N+) hydrogen bond in the mono-protonated derivatives leads to a stable, seven-membered ring structure. Thus, for example, the measured PA of l,6-diazabicyclo[4.4.4]tetradecane (73) is 228.3 kcalmol-1, about 11 kcalmol-1 higher than its monoamine analog 75, despite the similar, inwardly pyramidalized, nitrogen conformation of both neutral amines. 

The direct A -nitration of the amino groups of the hexahydrotriazine (23) is only possible due to the inherent low basicity of the methylenediamine functionality. The methylenediamine unit is present in many cyclic and bicyclic polyamines and these are potential precursors to energetic polynitramines. Unfortunately, this route to polynitramines is rarely possible because such polyamines are usually intrinsically unstable and will readily equilibrate to a lower energy, less strained system. For the same reason, polyamines containing the methylenediamine functionality are difficult to prepare and isolate, often rapidly decomposing in both aqueous and acidic solution. A far more common route involves the preparation of iV-protected versions of the polyamine followed by nitrolysis (Section 5.6). Even so, examples of heterocyclic methylenediamine iV-nitration exist. 

Polyelectrolytes (most notably ionic cellulose derivatives and crosslinked polyacid powders) are also commonly used as matrices, binders and excipients in oral controlled release compositions. In these applications, the polyelectrolytes provide hydrophilicity and pH sensitivity to tablet dosage forms. Acidic polyelectrolytes dissociate and swell (or dissolve) at high pH values whereas basic polyelectrolytes (for instance, polyamines) become protonated and swell at low pH. In either case, swelling results in increased permeability [290], thereby allowing an incorporated drug to be released. 

One of the first so-called potassium sparing, nonthiazide diuretic agents contains a pterdine nucleus. This is reflected in the use of the pterdine staring material tetra-aminopyrimidine (38-2) in the synthesis. Thus, reaction of benzaldehyde with that polyamine and potassium cyanide leads to the formation of the cyanohydrinlike a-aminonitrile (63-2) from reaction of the most basic amino group. Treatment of the intermediate with a base leads to the addition of the amine to the nitrile to give the dihydropteridine (63-3). Simple exposure to air leads to dehydrogenation and the formation of triamterine (63-4) [65]. 

One of the earliest references to a reaction in solution, which, as we now realize, depends upon the formation of a coordination compound, was recorded by Pliny who stated that the adulteration of copper sulfate by iron sulfate could be detected by testing with a strip of papyrus soaked in gall-nuts, when a black colour developed if iron were present. A. Libavius (1540-1616) noted how ammmonia present in water could be detected by the blue colour formed with a copper salt and A. Jacquelain (1846) actually determined copper salts in terms of the blue colour formed on adding ammonia. Later developments used coordination compounds formed from ethylenediamine and other polyamines.3 T. J. Herapath determined iron(III) as its red isothiocyanate complex in 1852 and the basic procedure is used today.3... 

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