Composite polyanion

The use of lanthanide cations as linkers in anions like 2 and 6, can be extended to the synthesis of even larger entities (7). We have recently shown that the building blocks themselves may be composite polyanions. Thus, reaction of 3 with lanthanide cations leads to dimeric (9) and polymeric (10) assemblies. 

Morishima et al. [42] prepared polyanions (A-x, 3) of various charge densities tagged with the merocyanine dye (Me) by terpolymerization of acrylic acid (AA), acrylamide (AAm), and a small mole fraction of l-(2-methacryloyloxyethyl)-4-(2-(4-hydroxyphenyl)ethenyl)pyridinium bromide (MA-Mc). Since these polyanions carry only 1 mol% of the MA-Mc units, they can practically be treated as copolymers of AA and AAm with a wide range of composition. 

A composition containing polyanionic cellulose and a synthetic polymer of sulfonate has been tested for reducing the fluid loss and for the thermal stabilization of a water-based drilling fluid for extended periods at deep well drilling temperatures [812]. 

Poly- anion Blend No. Composition of Polyanion Blend Composition of Polycation Blend Poly- cation Blend No. 

In a review, Van der Lugt (1996) observed that a number of liquid alloys (K-Pb, Rb-Pb, Cs-Pb, K-Sn, Rb-Sn, Cs-Sn, K-Te) behave as if all the anions were in the form of perfect simple Zintl anions like tetrahedra and dumbbells this being suggested by the behaviour of many physical properties (resistivity, thermodynamic properties, etc.) as a composition function. In this context a simple Zintl ion was defined as a polyanion that assumes the same configuration as a neutral isoelec-tronic element. A similar definition was reported by Van der Lugt and Verkerk... 

Figure 6,4 Ternary plot of singly bonded oxygen 0 , silicon Si and bridging oxygen in each kind of polyanion. Shaded areas compositional ranges 6.31 and 6.33. Reprinted from Ottonello (1983), with kind permission of Theophrastus Publishing and Proprietary Co.

Owing to these characteristics, PG has been extensively used for the adsorption of DNA and its derivatives. DNA was successfully adsorbed on PG by dry-adsorption at 100 °C [67]. The electrodes were stored in TriS buffer at 4 °C without loss of DNA, showing that DNA was firmly adsorbed on PG. It was demonstrated that the adsorbed ODN was also able to be hybridized with its complementary strand, suggesting that although DNA bases are compromised in the adsorption, they are still available for hybridization [67]. A composite film of DNA and the polyanionic perfluorosulfonated ionomer Nation was cast on PG by the layer-by-layer procedure performed by dry-adsorption [68]. In another approach, the PG surface was electrochemically pretreated at - 1.7 V for 60 s. DNA was then wet-adsorbed at the pretreated electrode surface from solutions containing 0.2 M NaCl, 10 mM Tris- HCl, pH 7.4, for 1 min followed by rinsing the electrode with distilled water [69,70]. 

Acidic properties of heteropoly compounds in the solid state are sensitive to countercations, constituent elements of polyanions, and tertiary structure. Partial hydrolysis and inhomogeneity of composition brought about during preparation are also important in governing the acidic properties. There are several possible types of origins of acidity (5) ... 

The quantum yield of the [Ru(bpy)3]2 + photosensitized reduction of Co(III)-Schiff base complex cation in aqueous solution is greately affected by the composition of the polymer-supported polyanionic donors such as vinylbenzylamine-iV,iV-diacetate-... 

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