Polymers containing transition elements

Selective extraction experiments were then performed to see transference of some transition elements (Cu ", Ni ", Co ", and Fe " ) from the aqueous phase to the organic phase by the synthesized polymeric calixarenes. Phase-transfer studies in water-chloroform confirmed that polymer 2b and 3b were Fe ion-selective as was its monomer (1). Extraction of Fe " cation with 2b and 3b was observed to be maximum at pH 5.4. Only trace amounts of other metal cations such as Cu, Ni ", and Co " were transferred from the aqueous to the organic phase (Table 3). Furthermore, the extracted quantities of these cations remained unaffected with increasing pH. The effect of pH on the extraction of 3b was lower and 56% extraction was accomplished even at pH 2.2. The extraction experiments were also performed with calix[4]arene (1) the ratio was 8.4% at pH 2.2. The polymeric calix[4]arenes were selective to extract Fe " from an aqueous solution, which contained Cu +, Ni, Co ", and Fe " cations, and it was observed that the... 

A wide range of p-block elements and transition metals have been incorporated into silicon-oxygen ring systems (heterocyclosiloxanes), primarily with a view to their use as precursors to Si-O polymers incorporating another element. The most common synthetic approaches to six-membered heterocyclosiloxanes containing another p-block element involve cyclocondensation reactions between 1,3-dichloro- or 1,3-dihydroxytetraalkyl/aryldisiloxane... 

MOFs/CPs, as the majority of these materials are based on transition metal, and more recently, lanthanide chemistry, yet a review of polymeric materials containing uranium (from more of a polymer chemistry perspective) has appeared recently. We will compare and contrast some uranium specific issues to those of the transition elements as we feel that the unique coordination geometries of the actinides (in particular U(VI)) result in a number of stmctural features, synthetic challenges, relevance to environmental issues, and opportunities for development of functional materials. 

D. R. Tyler, Mechanistic Aspects of the Photodegradation of Polymers Containing Metal-Metal Bonds Along Their Backbones, Chapter 4 in Macromolecules Containing Metals and Metal-Like Elements, Vol. 6, Transition Metal Containing Polymers, Eds., A. Abd-EI-Aziz, C. E. Carraher, C. H. Pittman, Jr., and M. Zeldin, pp. 77-109, Wiley, Hoboken, NJ, 2006. 

Two poly(cyclodiborazane) polymers containing group-10 transition metal-acetylide groups P50 and P51 were prepared by Chujo et al. and represent a new kind of organometal-lic acetylide polymers functionalized with group-13 boron elements in the main chain.78 The structures of P50 and P51 were confirmed by IR and NMR ( H, 31P, and nB) spectra. The optical properties were studied by UV-vis absorption and emission measurements. It was shown that these polymers display extended -conjugation length via transition metal and boron atom with enhanced air- and moisture stability. 

The technology of plasma formation of metal-containing polymers in the form of thin films dates from 1963, when Bradley and Hammes(15) prepared specimens from some forty different materials, and studied their electrical conductivities. Included in the study were organic compounds of iron, tin, titanium, mercury, selenium, and arsenic. The presence of a metal or transition element in the polymer did not lead to special electrical properties compared to the purely organic polymers studied. 

The selectivity to furfuryl alcohol is not influenced by the size of the active site. Promotion of the platinum catalyst by compoimds containing non-transition elements enhances the selective activation of the carbonyl group considerably. In the hydrogenation over the PtSn catalysts it is shown that the selectivity to furfuryl alcohol is dependent on the reaction temperature. At higher temperatures the catalyst is probably self-poisoned by carbonaceous deposits or polymers made from furfural or its fragments and the selectivity decreases. 

Polymers that Contain Main-chain Metal-Metal Bonds that Involve Transition Elements... 

The goal of this chapter is to present an overview of reports in the scientific literature that involve the use of microwave heating in the preparation of inorganic and organometallic compounds. For practical purposes, no attanpt has been made to cover compounds of all elements. The scope has been limited to coordination compounds and organometallic complexes containing transition metals. The focus is on molecular compounds and not on materials that could be classified as nanoparticles, polymers, supported catalysts, metal-organic frameworks, or solid-state materials. 

Polymers Containing Main-Chain Metal-Metal Bonds That Involve Transition Elements 1189... 

Supramolecular Polymers That Contain Metal-Metal Interactions Involving Transition Elements 1199 6.5... 

Transition Metal cr-Acetylide Polymers Containing Main Group Elements in the Main Chain Synthesis, Light Emission and Optoelectronic Applications... 

Transition Metal tr-Acetylide Polymers Containing Main Group Elements... 

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