Platinum poly

Liquid crystal polymers (LCPs) have been a source of considerable interest for some time, as they have been shown to offer particular advantages in terms of their processability and physical properties which make them attractive in a wide range of engineering applications.346 Serrano and his colleagues have reviewed metallomesogenic polymers, including the liquid crystalline properties of several of the platinum poly-yndiyl polymers described above.85,86... 

Guha, S., Frazier, C. C., Porter, P. L., Kang, K., Finberg, S. E., Measurement of the 3rd-order hyperpolarizability of platinum poly-ynes. Optics Letters 1989,14, 952-954. 

Wong, W.-Y. Chan. S.-M. Choi, K.-H. Cheah, K.-W. Chan, W.-K. Synthesis, optical and photoconduction properties of platinum poly-yne polymers functionalized with electron-donating and electron-withdrawing bithiazole units. Macromol. Rapid Commun. 2000, 21, 453-457. 

Detailed studies have been performed on the photophysics of a range of Pt poly-ynes [68, 75-77], and the energy-gap law for triplet states in a series of platinum poly-ynes has been established [78]. Convincing evidence for Jt-conjugation between metal sites in the main chain has been provided by some of the experiments [75]. The photophysics of polymers with fluorene and carbazole spacers has also been investigated in depth, and the studies indicate that the singlet state extends over more than one repeat unit whereas the triplet state is strongly localized [79]. 

The nature of the stabilizing layer around the platinum catsdyst particles has a significant effect on the efficiency of the catalyst. A comparison of radiolytically produced platinum/poly-iV-methylol acrylamide sols with platinum sol (from HjPtClg chemical reduction) stabilized by a range of other polymers showed that... 

The platinum poly-ynes show attractive physical properties, third-order optical non-linearity [107-109] and the formation of lyotropic liquid crystalline... 

NONLINEAR OPTICAL THIN FILMS OF PLATINUM POLY-YNES... 

The imaginary part of the third-order hyperpolarizability (y) was measured for a series of platinum poly-ynes in both solution and thin-film form, and for a group of related platinum-organic species. 

The platinum poly-yne films presented here have figures of merit similar to that of film 1 (Table 2), a well-known film with high nonlinearity. While the nonlinearities of the platinum poly-yne films are usually higher than that of film i, the absorption coefficients, a, are also larger. 

PMMA migrate to the interfaces (i.e. act as a surfactant) and effectively compatibilise the polymer blend [234], TEM analysis of nanostructured cured elastomeric sealant compositions prepared by sonicating a mixture of silylated apophyUite filler in PDMS showed unambiguously that silicate layers are exfoliated [235]. Watkins et al. [174] have studied platinum/poly(4-methyl-l-pentene) (PMP) nanocomposites by means of TEM. For nanocomposite science and technology, cfr. also ref. [236]. 

Salts of neodecanoic acid have been used in the preparation of supported catalysts, such as silver neodecanoate for the preparation of ethylene oxide catalysts (119), and the nickel soap in the preparation of a hydrogenation catalyst (120). Metal neodecanoates, such as magnesium, lead, calcium, and zinc, are used to improve the adherence of plasticized poly(vinyl butyral) sheet to safety glass in car windshields (121). Platinum complexes using neodecanoic acid have been studied for antitumor activity (122). Neodecanoic acid and its esters are used in cosmetics as emoUients, emulsifiers, and solubilizers (77,123,124). Zinc or copper salts of neoacids are used as preservatives for wood (125). 

Platinum-cobalt alloy, enthalpy of formation, 144 Polarizability, of carbon, 75 of hydrogen molecule, 65, 75 and ionization potential data, 70 Polyamide, 181 Poly butadiene, 170, 181 Polydispersed systems, 183 Polyfunctional polymer, 178 Polymerization, of butadiene, 163 of solid acetaldehyde, 163 of vinyl monomers, 154 Polymers, star-shaped, 183 Polymethyl methacrylate, 180 Polystyrene, 172 Polystyril carbanions, 154 Potential barriers of internal rotation, 368, 374... 

Very low asymmetric induction (e.e. 0.3-2.5%) was noted when unsymmetrical sulphides were electrochemically oxidized on an anode modified by treatment with (— )camphoric anhydride or (S)-phenylalanine methyl ester299. Much better results were obtained with the poly(L-valine) coated platinum electrodes300. For example, t-butyl phenyl sulphide was converted to the corresponding sulphoxide with e.e. as high as 93%, when electrode coated with polypyrrole and poly(L-valine) was used. 

Several alkyl aryl sulfides were electrochemically oxidized into the corresponding chiral sulfoxides using poly(amino acid)-coated electrodes448. Although the levels of enan-tioselection were quite variable, the best result involved t-butyl phenyl sulfoxide which was formed in 93% e.e. on a platinum electrode doubly coated with polypyrrole and poly(L-valine). Cyclodextrin-mediated m-chloroperbenzoic acid oxidation of sulfides proceeds with modest enantioselectivity44b. 

Poly crystalline silver layer electrodeposited on a polycrystalline platinum electrode. 

ControlW potential electrolyses of dibromostilbenes at poly-7i coated platinum foils gave results similar to those previously observed The electrodes lose... 

Wang H, Baltruschat H. 2007. DEMS study on methanol oxidation at poly- and monocrystalline platinum electrodes The effect of anion, temperature, surface structure, Ru adatom, and potential. J Phys Chem C 111 7038-7048. 

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