摘要:

Phthalocyanines1-3were used in combinations with polymers in order to investigate reduction/reoxidation of thin film electrodes, photoinduced reduction of dioxygen at the junction of thin film electrodes to an electrolyte, and dioxygen reduction in the dark (fuel cell reaction) at dispersions of phthalocyanines on carbon supports. Electrochromic reduction/reoxidation of phthalocyanines also occurs readily inside a polymer matrix if intermolecular particle contact exists. A significant photoreduction of dioxygen is observed if O2can form trapped states inside of the bulk of the film, with the result of enhanced photoconductivity. The kind of polymer is of striking influence. Phthalocyanines with central metals forming localized ionized states with dioxygen are active electrocatalysts for dioxygen reduction in the dark if they are finely dispersed on a carrier. The influence of both phthalocyanine and polymer component in each of the three-mentioned processes is discussed.

ISSN:0022-233X    

DOI:10.1080/00222339009349689

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

摘要:

Formation and magnetic properties of π-conjugated phenoxy radicals bearing a porphyrin macrocycle or a polyacetylenic backbone are described. Tetrakis(3,5-di-t-butyl-4-hydroxyphenyl)porphinato-metals (7-M) [M = Zn(II), VO(II), and Cu(II)] were oxidized to give the corresponding stable monoradical and biradical. Magnetic properties of the radical species depend on the magnetic orbital of the central metal ion. ESR hfs structure reveals that the biradical for7-Znand—VOare in the triplet (S = 1) and quartet state (S = 3/2), respectively. Poly(3,5-di-t-butyl-4-hydroxyphenylacetylene) (8) and poly(p-ethynylphenylhydrogalvinoxyl) (9) with molecular weights of ∼ /104are characterized. ESR spectra with hyperfine structure for8indicate that the phenoxy radicals are conjugated with the polyacetylenic main chain over ∼7 monomer units as a “neutral soliton.” Formed polyradicals for8and9are surprisingly stable, even in the solid state, due to resonance stabilization and/or steric effect of the conjugated main chain. An antiferromagnetic interaction is observed for oxidized8with a spin concentration above 10 mol%.

ISSN:0022-233X    

DOI:10.1080/00222339009349690

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

摘要:

Electron transfer reactions of Co(NH3)5PAA (PAA = polyacrylic acid) with either the polyanionic polymer-bound ferrous chelate, Fe11P-SS (P-SS = vinylbenzylaminediacetate-co-styrenesulfonate) or the uncharged polymer-bound ferrous chelate, Fe11P-VPRo (P-VPRo = vinylbenzylaminediacetate-co-vinylpyrrolidone), and the Ru(bpy)2+3photosensitized reduction of Co(NH3)5PAA have been investigated in aqueous solutions at pH 5.4,I= 0.06 (Iis ionic strength), and 25°C. For the ferrous chelate reductions, the second-order rate constants for Fe11-PSS and Fe11P-VPRo were almost equal to that for the corresponding nonpolymer-bound ferrous chelate, Fe11BDA (BDA = benzylaminediacetate). The results indicate that there is no appreciable steric hindrance due to the polymer chains of the polymer-bound ferrous chelates and that the effect of columbic repulsion force between the polyanion chains can be ignored for the reaction of Co(NH3)5PAA with Fe11P-SS. The results also suggest that there are two kinds of the pendant Co(III) species, “reactive” and “inert.” The inert Co(III) species are shielded by the polymer chains from attack of the Fe(II) chelates that are present in the bulk solutions. A similar reaction behavior was observed in the Ru(bpy)2+3photosensitized reduction of Co(NH3)5PAA at pH 5.4. For the Co(III) complex having an extremely few Co(III) complex moieties on the polymer chain, almost all of the Co(III) groups were hardly reduced by the excited state of Ru(bpy)2+3, and reverse quenching occurred due to binding of the Ru(bpy)2+3to the polyacrylic acid chain of the polymer complex. On the other hand, for Co(NH3)5PAA with a relatively large number of the Co(III) moieties on the polymer chain, lifetime measurements at a higher concentration of the Ru(bpy)2+3showed a double-exponential fit, which suggests that there are two parallel decay processes. The fast and slow components mainly correspond to the decays: Ru(bpy)2+3quenched by Co(III) and reverse quenching due to binding of Ru(bpy)2+3into the compact polymer chains.

ISSN:0022-233X    

DOI:10.1080/00222339009349691

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

摘要:

Macromolecule-copper(I) chloride complexes have been prepared for the separation of carbon monoxide and ethylene from gas mixtures with hydrogen, nitrogen, carbon dioxide, methane, and water. A toluene solution of a polystyrene-aluminum copper(I) chloride complex can separate carbon monoxide selectively and retains this function even on contact with gas containing water. Strong charge-transfer absorption bands have been found in the 380-500 nm region for the toluene solution of polystyrene-aluminum copper(I) chloride complex. A solution of 1, 3-diphenylpropane-aluminum copper(I) chloride complex also exhibits similar absorption bands. A continuous variation plot using the chemical shift change in13C-NMR shows a 1:1 interaction between 1,3-diphenylpropane and aluminum copper(I) chloride. These results suggest a two-way interaction between the adjacent phenyl groups of polystyrene and aluminum copper(I) chloride. A resin bead of crosslinked polystyrene-aluminum copper(I) chloride complex has been prepared as a solid adsorbent. The water resistance of the solid macromolecular complex depends on the nature of the solvent used in the preparation of the solid adsorbent. Carbon disulfide is a suitable solvent. A selective adsorbent of ethylene has been prepared from a macroreticular polystyrene resin with primary and secondary amino groups and copper(I) chloride. The selectivity of ethylene against ethane and that of carbon monoxide against carbon dioxide increase with an increasing amount of supported copper(I) chloride.

ISSN:0022-233X    

DOI:10.1080/00222339009349692

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

摘要:

The structure of 1,4,8,11-tetraazacyclotetradecane (cyclam) complexes with nickel(II) and copper(II) ions in aqueous solution has been determined by the x-ray diffraction method at 25°C. The [Ni-(cyclam)]2+complex has a square-planar structure with four nitrogen atoms of the cyclam, and the Ni-N bond length has been determined to be 198 pm. Upon the addition of ammonia, the color of the nickel(II)-cyclam solution turns to deep purple and the [Ni(NH3)2(cyclam)]2+complex is formed. The complex has a regular octahedral structure with an additional two NH3molecules along the axis vertical of the cyclam plane, and the Ni-N (NH3and cyclam) bond lengths are 209 pm. The copper(II)-cyclam complex in the aqueous solution is a distorted octahedron with two water molecules along the elongated axis. The axial Cu—O and equatorial Cu—N bond lengths are 277 and 210 pm, respectively.

ISSN:0022-233X    

DOI:10.1080/00222339009349693

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

摘要:

The functional group capacity and the percentage of functional group conversion of crosslinked polystyrene resin bearingN-methyl-2-thioimidazole (MTIR) synthesized under optimum conditions are as high as 4.08 mmol/g resin and 96.0%, respectively. The apparent activation energies of sorption of MTIR for Au(III) and Pt(IV) are 13.1 and 13.4 kJ/mol, respectively. The sorption behavior of MTIR for Au(III), Pt(IV), and Pd(II) obeys the Freundlich and Langmuir isotherms. The sorption capacities of MTIR for Au(III), Pt(IV), and Pd(II) are as high as 4.33, 2.12, and 2.33 mmol/g resin, respectively. Au(III), Pt(IV), and Pd(II) adsorbed on MTIR can be eluted quantitatively by the eluant. The resin can be regenerated easily and reused without an obvious decrease in the sorption capacity for Au(III) and Pd(II). The resin has high sorption selectivity for noble metal ions. Au(III) can be separated quantitatively in the presence of high concentrations of Cu2+, Fe3+, Ni2+, and Mn2+. The recovery of platinum from the spent industrial catalysts is 98.6% by MTIR. The preconcentration and separation of palladium and platinum from the anode deposits of electrolysis of crude copper have been investigated. The resin may have potential industrial uses.

ISSN:0022-233X    

DOI:10.1080/00222339009349694

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

摘要:

The sequence distribution of the monomelic units in the styrene-acrylic acid copolymer has been obtained by calculation. The probability of long sequences of styrene increases with an increase in the content of the monomer in the copolymer. The highest distribution of short sequences of styrene takes place for the copolymer containing equimolecular amounts of styrene and acrylic acid. The copolymer which has this latter structure is inadequate for the synthesis of highly active supported complexes. When the distributions of long and short sequences of styrene are approximately equal, the activity of the Nd and Fe prepared polymer complexes is higher.

ISSN:0022-233X    

DOI:10.1080/00222339009349695

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

摘要:

New types of air-stable metal-carbon composites which contain ultrafine metal particles (Fe, Co, Ni, Pd, Pt, Rh, Cu, etc.) uniformly dispersed in a carbon matrix were obtained by pyrolysis of a variety of soluble organometallic polymers, macromolecular-metal complexes, and blends of coal pitch with metal complexes at 400-1400°C in N2. Some of their unique physical properties and functions are noted.

ISSN:0022-233X    

DOI:10.1080/00222339009349696

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

摘要:

{η5-C5H4[CH(CH3)OC(O)CH = CH2])Mn(CO)3, {η5—C5[CH-(CH3)OC(O)C(CH3)=CH2]]Mn(CO)3, and {η5—C5H4[CH(CH3)-OC(O)CH=C(CH3)2])Mn(CO)3were synthesized (63, 57, and 51%, respectively) from {η5—C5H4[CH(CH3)OH])Mn(CO)3, toluene-sulfonic acid, and the acrylic, methacrylic, and dimethylacrylic acids, and from (η5-C5H4[CH(CH3)OH]}Mn(CO)3, pyridine, and the acrylic, methacrylic, and dimethylacrylic acyl chlorides [26, 48, and 25% (impure), respectively]. No product was obtained when NaH was used as the base in the latter method. The acrylate and methacrylate monomers were bulk homopolymerized at 65°C with AIBN (75% yield,Mn= 88,550 g/mol; 78% yield,Mn= 349,350 g/mol, respectively). The dimethylacrylate did not polymerize under these conditions. The polymers lost vinylcymantrene upon heating to 257 and 279°C, respectively. The polymers did not exhibit a clearTgbut were observed to soften at 85 and 160°C, respectively, and they could be pulled into fibers.

ISSN:0022-233X    

DOI:10.1080/00222339009349697

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

摘要:

Liquid crystalline side-chain polymers (3b-3f) crosslinked by atransPt(II) complex were synthesized by a ligand exchange reaction with dichlorobis(benzonitrile)platinum(II) and poly(methylsiloxane) (3a) bearing ap-cyanobiphenyloxy mesogen unit attached to the polymer backbone by a flexible spacer group. The amount (x) ofp-cyanobiphenyloxy mesogen coordinating to the Pt(II) ion in polymers3b, 3c, 3d, 3e, and3fwas 4.9, 9.7, 14.8, 20.2, and 49.6 mol%, respectively. The effect of Pt(II) coordination on the thermotropic liquid crystalline behavior of3awas examined by DSC, x-ray diffraction, and polarizing microphotography. Polymers3a-3dexhibited a nematic mesophase betweenTgandTc.On the other hand,3e-3f, which have a large amount of Pt(II)-coordinating mesogen, did not show a definite nematic mesophase, but exhibited an ambiguous one. The introduction of Pt(II) ion into3aresulted in a crosslinked structure and consequently prevented the formation of the ordered nematic mesophase.

ISSN:0022-233X    

DOI:10.1080/00222339009349698

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor