Polymers Containing Metal Carbonyl Complexes

Bifunctional hydroxyl monomers functionalized with rhenium or iron complexes were reacted with terephtaloyl chloride to produce polymers containing metal-carbon o- or jt-bonds (scheme 31).  

The synthesis of homopolymers and copolymers of jt-(2,4-hexadienyl acry-late)tricarbonyliron with styrene, methyl acrylate, acrylonitrile, and vinyl acetate were first reported in 1973. These polymers could undergo protonation to yield the jt-allyliron polysalts 105. These compounds were easily transformed into new types of functional materials due to the ease of nucleophific attack on the positively 

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There are a number of different types of polymers that contain metal carbonyl complexes attached to polymer backbones and side chains. In the 1970s, Pittman and coworkers reported the synthesis and polymerization of a wide range of vinyl monomers containing transition-metal-coordinated cyclopentadienyl rings. Polymer 21 is an example of a copolymer containing chromium and manganese complexes in the side chain. Another class... 

In the case of metal-containing PAN the spectral picture is qualitatively the same (as compared with the initial PAN) however, ftie nature of tiie metal carbonyl introduced into the polymer somewhat influences the character of file transformations. By FTIR, ESCA and ESR, it was found that under thermal treatment in air at 220 C, first metal carbonyl complexes decompose (by FTIR spectroscopy tungsten and molybdenum carbonyl complexes lose carbon monoxide at 150-160 C, chromium carbonyl ones at 110°C) and chromium, molybdenum and tungsten oxide particles form. 

Studies on the immobilization of Pt-based hydrosilylation catalysts have resulted in the development of polymer-supported Pt catalysts that exhibit high hydrosilylation and low isomerization activity, high selectivity, and stability in solventless alkene hydrosilylation at room temperature.627 Results with Rh(I) and Pt(II) complexes supported on polyamides628 and Mn-based carbonyl complexes immobilized on aminated poly(siloxane) have also been published.629 A supported Pt-Pd bimetallic colloid containing Pd as the core metal with Pt on the surface showed a remarkable shift in activity in the hydrosilylation of 1-octene.630... 

It has become clear that the carbon-rich hb-PYs are readily curable (from ca. 150 °C), thermally stable (up to ca. 550 °C), and pyrolytically carboniz-able (yield up to 80% at 900 °C). Furthermore, their triple bonds are easily metallizable by the complexations with cobalt carbonyls. Since the polymer complexes contain a large number of metal atoms, we tried to utilize them as precursors for fabrication of metalloceramics. The pyrolyses of the polyyne-cobalt complexes at 1000 °C for 1 h under nitrogen furnished ceramic products 83 and 84 in 50%-65% yields (cf., Scheme 31). All the ceramics were magnetizable and could be readily attracted to a bar magnet. 

Micelle Formation via Complexation. Micellization of molecu-larly soluble block copolymers due to interaction with metal compounds was observed in both organic media and water, if one of the two blocks (for a diblock copolymer) is inert while the other is able to form complexes with metal compounds. Micellization of Pd-, Pt-, and Rh-containing polymers derived from PS-fc-PB with a short PB block was first reported in 1998 [48], The crosslinks formed due to complexes between metal atoms and PB blocks of different macromolecules were shown to cause micellization. By contrast, Fe carbonyl... 

The ratio of vinyl-to-carbonyl placement depends upon the nature of the complex. Polymers formed by complexes of metallic salts with triphenylphosjphine contain considerably less aldehyde groups than those formed with triphenylphosphine alone. ... 

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