Poly polymer complexes

Polymer/Polymer Complexes. PVP complexes with other polymers capable of interacting by hydrogen-bonding, ion-dipole, or dispersion forces. For example mixing of PVP with poly(acryHc acid) (PAA) in aqueous solution results in immediate precipitation of an insoluble complex (113). Addition of base results in dismption of hydrogen bonding and dissolution (114—116). Complexes with a variety of poly-acids (117) and polyphenols (118) have been reported. The interest in compatibiHty on a molecular level, an interesting phenomenon rarely found to exist between dissimilar polymers, is favored by the abiHty of PVP to form polymer/polymer complexes. 

We also found the saturation kinetics for alkaline hydrolyses of 44 (PNPA), 3-nitro-4-acetoxybenzoic acid 56 (NABA), and 3-nitro-4-acetoxybenzenearsonie acid 57 (NABAA) in the presence of QPVP1025. If ester-polymer complex formation occurs prior to the attack of OH-, Eq. (5) holds, according to Bunton etal. 103 where K is the equilibrium association constant of polyelectrolyte (PE) and ester (S), and kt the first-order rate coefficients1035, PE, S, and P indicate the poly-... 

The organoboron polymer complex was prepared as follows. First, poly(organoboron halide)55 was prepared according to the reported method, by hydroboration polymerization between 1,7-octadiene and the monobromoborane dimethylsuffide complex. The polymer obtained was then reacted with half an equivalent of methanol and 1-methylimidazole to give the corresponding copolymer efficiently (scheme 4). The structure of the polymer was characterized by H- and UB-NMR spectra. 

Seki and Tirrell [436] studied the pH-dependent complexation of poly(acrylic acid) derivatives with phospholipid vesicle membranes. These authors found that polyfacrylic acid), poly(methacrylic arid) and poly(ethacrylic acid) modify the properties of a phospholipid vesicle membrane. At or below a critical pH the polymers complex with the membrane, resulting in broadening of the melting transition. The value of the critical pH depends on the chemical structure and tacticity of the polymer and increases with polymer hydro-phobicity from approximately 4.6 for poly(acrylic acid) to approximately 8 for poly(ethacrylic acid). Subsequent photophysical and calorimetric experiments [437] and kinetic studies [398] support the hypothesis that these transitions are caused by pH dependent adsorption of hydrophobic polymeric carboxylic acids... 

Bis(2,2 -bipyridyl)ruthenium(II) was anchored onto poly(4-vinyIpyridine) (PVP) (6) 28>29), but the polymer complex is not suitable as photocatalyst, because it is susceptible to photoaquation. A polymer complex containing Ru bpy) + pendant groups was first prepared by reaction of polystyrene (PSt) as shown in Eq. (15)30). 

Polymer complexes of Ru(bpy)2+ (16, 17) were prepared from poly(6-vinyl-2,2 -bipyridine) and poly(4-methyl-4 -vinyl-2,2 -bipyridine)36) the sensitized reduction of MV2 + with these complexes was studied by flash photolysis37). In the electron transfer... 

In this system RuO, powders were coated with the water insoluble polymer complex (i8) and used as suspensions. Ru02 colloids were stabilized by the water soluble Ru complex prepared from poly(Vbpy) and used (see also Sect. 3.4). 

Scheme 6 represents coordinate polymers. A low-molecular-weight compound with multidentate groups on both ends of the molecule grows into a linear polymer with metal ions, and the polymer chain is composed of coordinate bonds. The parquetlike polymer complexes, poly(metal-phthalocyanine) and poly(metal-tetracyano-ethylene), are classified into Scheme 7. They are formed by inserting metal ions into planar-network polymers or by causing a low-molecular-weight ligand derivative to react with a metal salt and a condensation reagent.

The suggested rod like structure of the pendant-type FVP-Co(III) complex is supported by the viscosity behavior of the polymer-complex solution (Fig. 3)2 The PVP-Co(III) complexes have higher viscosity than PVP this suggests that the polymer complex has a linear structure and that intra-polymer chelation does not occur. The dependence of the reduced viscosity on dilution and the effect of ionic strength further show that Co(en)2(PVP)Cl] Cl2 is a poly(electrolyte). The polymer complexes with higher x values have a rodlike structure due to electrostatic repulsion or the steric bulkiness of the Co(III) chelate. On the other hand, the solubility and solution behavior of the polymer complex with a lower x value is similar to that of the polymer ligand itself. 

This reaction profile of the polymer complex has some similarities with the phenomenon of the polyelectrolyte-catalyzed reactions. It has been reported that the reactions between two positively charged species in aqueous solution are drastically accelerated in the presence of polyanionsS2 84 For example, the electron-transfer reaction between [Co(IIIXen)2(Py)Cl]2+ and [Fe(IIXOH2)6]2+ is very slow because the reaction occurs between two cations however, the addition of a small amount of poly(styrenesulfonate) accelerates the reaction by a factor of 103 84). This result is also interpreted as indicating that the two positively charged reactants are both concentrated in the polyanion domain, so that they encounter each other more frequently [Fig. 17(b)]. 

The first example of catalysis by a polymer-metal complex was presented by Lautsch et al. u3 Metalloporphyrin was linked to a poly(phenylalanine) chain by a peptide bond. The catalytic properties of this polymer-Fe(III)porphyrin complex were compared with Fe(III)porphyrin in the oxidative reaction of phenylenedi-amine. The catalytic activity of the polymer complex was twice as large as that for the corresponding analog. 

The hydrolysis of sodium pyrophosphate was effected by using some metal complexes of poly(methacrylacetone) as catalysts138. The catalytic activity of the polymer complexes declined in the following order Zr(IV)0 > U(VI)02 >... 

Kitano, S., Koyama, Y., Kataoka, K., et al. A novel drug delivery system utilizing a glucose responsive polymer complex between poly (vinyl alcohol) and poly( V-vinyl-2-pyrrolidone) with a phenylboronic acid moiety. J. Contr. Rel. 19 161—170, 1992. 

Mi, K. Y., Yong, K. S., Young, M. L., and Chong, S. C. Effect of polymer complex formation on the cloud-point of poly(Al-isopropylacrylamide) (PNIPAAm) in the poly(NIPAAm-co-acrylic acid) polyelectrolyte complex between poly(acrylic acid) and poly(l-lysine). Polymer 39 3703-3708, 1998. 

Schmidt, G, Enkelmann, V., Westphal, U., Droscher, M., and Wegner, G. (1985) Preparation of urea-poly(tetrahydrofuran) complexes and their application for fractionation of oligomers, Colloid Polym. Sci. 263, 120-127. 

Figure 4.15 Schematic representation of the sequential steps taken for the formation of multilayers based on electrostatic self-assembly using cationic polymers and anionic a-ZrP sheets (see text for further details). Reprinted from Coord. Chem. Rev., 185-186, D.M. Kaschak, S.A. Johnson, C.C. Waraksa,J. Pogue and T.E. Mallouk, Artificial photosynthesis in lamellar assemblies of metal poly(pyridyl) complexes and metalloporphyrins, 403-416, Copyright (1999), with permission from Elsevier Science...

Starburst polyacrylamines and their semiconducting complexes as potentially electroactive materials. [H. K. Hall, Jr., D. W. Polis, Polym. Bull. 1987, 77(5), 409-416] [ 604]. 

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