Polyammonium compounds

Indeed, most of the polyammonium compounds studied exhibited more or less pronounced catalysis of the hydrolytic cleavage of ATP. The most efficient compound in this series was 44 showing a pH-depent rate enhancement factor exceeding... 

Schueler, F. W. and Keasling, H. H. J. Am. Pharm. Assoc. 45, 792 (1956) see also chapter Interactions of Polyammonium Compounds with Acetyl Choline Receptors , this volume, J. Schmidt and M. A. Raftery, p. 175... 

INTERACTIONS OF POLYAMMONIUM COMPOUNDS WITH ISOLATED ACETYLCHOLINE RECEPTORS... 

Form I polyammonium catena-polyphosphate contains the shortest long-chain anions of several polymorphic forms having the same chemical composition.1 It is slightly soluble in water and gives a cloudy, viscous solution. The solubility increases with the quantity of solid phase present the apparent solubility of the pure compound at 25° has been estimated to be 0.15 g per 100 g of water.1 The compound is more soluble in hot water or in the presence of other dissolved... 

The complexation of coordination compounds may make it possible to control their photochemical behaviour via the structure of the supramolecular species formed. For instance, the binding of cobalt(m) hexacyanide by macrocyclic polyammonium receptors markedly affects their photoaquation quantum yield in a structure-dependent manner [8.73-8.77]. It thus appears possible to orient the photosubstitution reactions of transition-metal complexes by using appropriate receptor molecules. Such effects may be general, applying to complex cations as well as to complex anions [2.114]. 

Oxaazamacrocycles are molecules with combined crown ether and amino group properties for example, in dependence on the size of macrocyclic ring and the position of heteroatoms stable complexes with various metals can be formed [32]. Furthermore, when protonated, these compounds are excellent anion binders. In fully protonated polyammonium macrocycles, the coulom-bic attractions and hydrogen bond formation play a dominant role in the anion complexation. The receptors (R,R)-5 and (S,S,S,S)-6 were designed to bind dicarboxylates [33]. 

Polyammonium cryptands and tricyclic lactams probably represent the largest family of cryptand-type anion receptors known today and a detailed overview of the properties of these compounds lies outside the scope of this review. The interested reader is therefore referred to two recent reviews [11, 53]. Compound 35b in the following section is the only polyammonium cryptand besides 5 whose properties are described in this review in more detail to illustrate the effect of the incorporation of additional hydrogen bond acceptor sites on binding properties. 

Dry the residue on a good vacuum pump for 24 h. The free octaamine 17 (0.78 g, 87%) is obtained as a viscous oil. This compound turns yellow rapidly and should not be stored in this form but as its polyammonium salt (chloride or bromide as desired). Further details are given in Ref. 3. 

Recently, Frydman et al. successfully analysed the Co static powder spectra of a series of cobalamins and cobaloximes measured at 4,7, 7.1 and 11.8 TP As pointed out by the authors, there were considerable changes in the Co quadrupole coupling constants depending on the crystallization conditions of the cobalamins, whereas the Co chemical shift tensors remained fairly constant. It was suggested that the different behaviour of the EFG and chemical shift tensors is due to a different dependence of these tensors on an uncharacterized structural rearrangement when the cobalamins were recrystallized. Furthermore, the close resemblance between the Co NMR data of cobalamins and cobaloximes illustrates that cobaloximes are much better model compounds of cobalamins than cobaltoporphyrins. In a study of polyammonium cobalticyanide supercomplexes, Zhou et al. combined the use... 

Among the first to exploit totally synthetic water soluble host compounds to catalyze chemical reactions were Tabushi et. al. who found an accelerating influence of their newly developed polyammonium cyclophane 1 on the hydrolysis of aromatic chloroacetates These authors showed conclusively that a rapid association of substrate and 1 proceeds the rate limiting attack of solvent on the ester group. This step is amenable to buffer catalysis, too. Some relevant rate data are given in Table 1. The evaluation of these data now depends largely on definitions. Tabushi et al. chose to view their results in terms of a kinetic sul trate specificity manifested in ratios. As a corollary they state a marked specificity in the conversion of substrates 2-4. This is formally corr t but it bears the danger of misinterpretation and is certainly seductive to draw faulty conclusions. 

Pina. F. Parola, A.J. Photochemistry of supramolecular species involving anionic coordination compounds and polyammonium macrocyclic receptors. Coord. Chem. Rev. 1999. 185-186. 159-165. 

Polyammonium macrocycles are successful mimics of a variety of phosphoryl transfer enzymes. These simple compounds are noted for their capability to bind to a number of anions, including the simple phosphate and polyphosphates as well as more complex nucleotides. "Large" polyazacycloalkanes in their protonated forms have been found to exhibit ATP binding as well as ATPase activity. A general accepted mechanism for ATP hydrolysis catalyzed by polyaza macrocycles involve the formation of a ATP-receptor complex, held by electrostatic interaction and hydrogen bonds, followed by the formation of a covalent intermediate macrocyclic-phosphoramidate species, which is subsequently hydrolyzed (see Figure 2)P... 

There are many new and less well-known types of softening compounds such as pentaerythri-tol ditallowate [6], glycerine-based polyol esterquats [7], l,l-ethylene-( M(2-tallow-alkyl-3-methyl-imidazolinium) methyl sulfate [8], P-hydroxyethyl ethylenediamine derivatives [8], polyammonium... 

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