ChemInform Abstract: ANION COORDINATION CHEMISTRY: POLYGUANIDINIUM SALTS AS ANION COMPLEXONS

Dietrich, B.; Fyles, Deborah L.; Fyles, Thomas M.; Lehn, Jean‐Maríe

doi:10.1002/chin.198014086

Cited by 2 publications

(3 citation statements)

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“…The I3C-NMR. spectra of all the ligands prepared in general, and of 5 b in particular, are independent of counter anion (at constant pH) [25]. The observed protonation shifts reflect primarily the degree of protonation of the ligand and are not due to changes in the proportions of free and complexed 5b.…”

Section: -mentioning

confidence: 96%

“…6 ) All stability constants reported here were determined relative to a large (20-fold) excess of chloride anion; in general, when measured at two or more anion concentrations (hence two or more anion/chloride ratios), they were virtually independent of chloride concentration (within the limits of the experiment). No association could be detected between TREN3+ (5b3+) and chloride anion in methanollwater 9: 1 at pH 4.0 using a chloride specific ion electrode technique [25]. A complex having K s r 5 0 (log K,> 1.7) would have been observable under the conditions of the experiment (Ligand concentration, chloride concentration).…”

Section: B)mentioning

confidence: 97%

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Anion Coordination Chemistry: Polyguanidinium Salts as Anion Complexones

Dietrich¹,

Fyles²,

Fyles³

et al. 1979

Helvetica Chimica Acta

181

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SummaryThe synthesis of a series of polyguanidinium salts of potential interest as anion complexones is described. Among the various synthetic methods investigated, the polyguanidinium salts were found to be most conveniently prepared from polyamines via polypitroguanidine intermediates. The complexation of phosphate and carboxylate anions by these complexones and by related polyammonium salts were studied by analysis of pH-metric titration data. The ligands studied form relatively stable complexes (log K,= 2.0-4.0 for PO:-in water) which also present good selectivities in some cases. Both the stability and the selectivity of complexation are primarily governed by electrostatic forces and thus depend on charge accumulation in the interacting species; structural effects are also observed. Since the binding is primarily electrostatic, polyammonium salts form more stable complexes (at a given charge) than do polyguanidinium salts. However, whereas the complexation properties of the latter are independent of pH, the complexes of the former are observed only in the limited ranges of pH where both the protonated polyamine and the anion of interest can coexist. The polycationic ligands may, in principle, form chelate type anion complexes. Comparison with the corresponding single binding sites reveals an increase in complexation constant of about two or three orders of magnitude; this may be considered as a thermodynamic indication of a chelate effect for the polydentate ligands (by analogy with the well known effects displayed by cation complexones); however, structural data on the formation of chelate 'rings' are not yet available. The nature of the complexes and the prospects of anion complexones in various fields are discussed.

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Section: -mentioning

confidence: 96%

Section: B)mentioning

confidence: 97%

Anion Coordination Chemistry: Polyguanidinium Salts as Anion Complexones

Dietrich¹,

Fyles²,

Fyles³

et al. 1979

Helvetica Chimica Acta

181

View full text Add to dashboard Cite

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“…[30] However, the guanidinium groups present a more favorable geometry to form two linear hydrogen bonding interaction sites with various anionic groups. Since the charge on the guanidinium group is more delocalized than on the ammonium group, electrostatic interaction is expected to be stronger with the latter.…”

Section: Huval Et Al 240mentioning

confidence: 99%

Ammonium and Guanidinium Functionalized Hydrogels as Bile Acid Sequestrants: Synthesis, Characterization, and Biological Properties

Huval¹,

Holmes‐Farley²,

Mandeville³

et al. 2004

Journal of Macromolecular Science, Part A

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Novel cationic polymers as bile acid sequestrants (BAS) have been considered to be an attractive long-term therapy for the treatment of hypercholesterolemia. Due to the poor in vivo efficacy of the first generation of BAS like cholestyramine and colestipol, there is a need for discovering new generations of potent BAS. As part of our polymeric drug discovery efforts, we have developed a facile route to prepare functional hydrogels bearing pendant amine and guanidinium groups. The polymeric amines were prepared either by direct polymerization of amine containing monomers or by chemical modification of suitable polymeric precursors. Polymers bearing guanidinium groups were obtained by a polymer analog reaction on crosslinked polymeric amines (primary or secondary) using a readily available guanylating agent in aqueous medium. Incorporation of guanidinium groups to these polymers occurs under mild reaction condition. A numbers of polymer structures with pendant amine and guanidinium groups located at varying distances from the polymer backbone were obtained. These ORDER REPRINTS polymeric ammonium and guanidinium salts were evaluated in vivo as BAS and hence cholesterol lowering agents.

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ChemInform Abstract: ANION COORDINATION CHEMISTRY: POLYGUANIDINIUM SALTS AS ANION COMPLEXONS

Abstract: Die bequemste Art, die Titelverbindungen (IV)‐(VI) darzustellen, ist die Umsetzung z.B. des Diamins (I) in Wasser bei 5°C mit dem Nitroisoharnstoff (II) zum Derivat (III), dessen Hydrogenolyse in saurer Lösung zum Ethylendiguanidinium (IV) führt.

Cited by 2 publications

References 1 publication

Anion Coordination Chemistry: Polyguanidinium Salts as Anion Complexones

Anion Coordination Chemistry: Polyguanidinium Salts as Anion Complexones

Ammonium and Guanidinium Functionalized Hydrogels as Bile Acid Sequestrants: Synthesis, Characterization, and Biological Properties

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