Narrow Results

Vinylporphyrins containing one vinyl group at the pyrrole or benzene ring and their complexes with Cu²⁺ and Zn²⁺ have been obtained by the Wittig reaction. The compounds obtained were characterized by physicochemical methods. X-ray diffraction analysis of 5-(4-vinylphenyl)-10,15,20-triphenylporphyrin has been carried out. It is likely that the inclusion of the vinyl group is accompanied by weak electron effects on the macrocycles. The radical-induced copolymerization of meso-tetraphenylporphyrin monomers with the vinyl group in a benzene or pyrrole ring and their copper and zinc complexes with styrene and methacrylate was studied. Porphyrin comonomers decrease the overall polymerization rate and the number-average molecular weight of the products formed compared with the weight of polystyrene obtained under similar conditions. The main reasons for termination of chain growth by vinylporphyrins were revealed and some quantitative parameters of these reactions were obtained. IR and electronic absorption spectra of porphyrin-containing copolymers are discussed. According to the ESR spectra, the copper-containing centres in the copolymers are fairly remote from each other, and the metal-containing polymeric systems are magnetically dilute. The spectral luminescence properties of solutions of zinc 5-(4-vinylphenyl)-10,15,20-triphenylporphyrin–methyl methacrylate copolymers with various contents of porphyrin groups were studied. It was shown that a new long-wave band appears in the absorption spectra of the copolymers, the intensity of which depends on the copolymer composition, and the quantum yield of fluorescence decreases with increasing molar fraction of porphyrin groups.

A neutral nickel (II) catalyst D,{[O-(3-cyclohexyl)(5-Cl)C₆H₂-ortho-C(H)=N-2,6-C₆H₃(i-Pr)₂]Ni(Ph₃P)(Ph)} has been synthesized and characterized by ¹H-NMR, FTIR and elemental analysis. The results indicate that Al(i-Bu)₃ is an effective cocatalyst for the neutral nickel catalyst. With bis(1,5-cyclooctadiene) nickel(0) [Ni(COD)₂] or Al(i-Bu)₃ as a co-catalyst, the neutral nickel catalyst D is active for ethylene polymerisation and copolymerisation with polar monomers (tert-butyl 10-undecenoate(BU), methyl 10-undecenoate (MU), allyl alcohol (AA) and 4-penten-1-ol (PO)) under mild conditions. The resulting polymers were characterized by ¹H-NMR, FTIR, DSC, and GPC. From the comparative studies, Ni(COD)₂ is more active than Al(i-Bu)₃ for ethylene homopolymerization, while Al(i-Bu)₃ is more effective than Ni(COD)₂ for ethylene copolymerisation with polar monomers. The polymerization parameters which affect both the catalytic activity and properties of the resulting polyethylene were investigated in detail. Under the conditions of 20 μmol catalyst D and Ni(COD)₂/D = 3 (molar ratio) in 30 mL toluene solution at 45°C, 12 × 10⁵Pa ethylene for 20 min, the polymerization activity reaches as high as 7.29 × 10⁵gPE·(mol·Ni·h)^-1 and M_η is 7.16 × 10⁴g·mol^-1. For ethylene copolymerization with polar monomers, the effect of comonomer concentrations was examined. As high as 0.97 mol% of MU, 1.06 mol% of BU, 1.04 mol% of AA and 1.37 mol% of PO were incorporated into the polymer, respectively, catalyzed by D/Al(i-Bu)₃ system.

Rare-earth ternary catalysts Y(CCl₃COO)₃-ZnR₂-glycerin were prepared for the copolymerization of carbon dioxide and propylene oxide (PO), where dialkylzincs (ZnR₂) were diethylzinc, di(n-propyl)zinc, di(n-butyl)zinc, di(i-propyl)zinc, di(i-butyl)zinc, di(s-butyl)zinc, respectively. The Y(CCl₃COO)₃-ZnR₂-glycerin catalysts displayed the highest catalytic activity at the molar ratio of Y(CCl₃COO)₃:ZnR₂:glycerin = 1:20:10. In the same copolymerization condition, catalysts containing dialkylzincs with branched alkyl group showed lower catalytic activity than that with primary alkyl group. For those catalysts including dialkylzincs with primary alkyl group, their catalytic activity decreases with increasing number of carbon atom in the alkyl group with the following sequence: Y(CCl₃COO)₃-ZnEt₂-glycerin > Y(CCl₃COO)₃-Zn(n-Pr)₂-glycerin> Y(CCl₃COO)₃-Zn(n-Bu)₂-glycerin. However, the alkyl group in the dialkylzinc does not influence the insertion of PO into the propagation chain end.

Chloro(5,10,15,20-tetraphenyl-porphyrinato)-aluminum/tetraethylammonium bromide (Et₄NBr) in combination with bulky Lewis acid was used for the copolymerization of CO₂ and cyclohexene oxide (CHO). Bulky Lewis acid having substituents at the ortho positions of the phenolate ligands, like methylaluminum bis(2,6-di-tert-butyl-4-methylphenolate), significantly shortened the induction period and raised the catalytic activity, the corresponding turnover frequency reached 44.9 h^-1 in 9 h, which was 23.8% higher than that from (TPP)AlCl/Et₄NBr binary catalyst. The resulting polycarbonate has carbonate linkage over 93% with number average molecular weight of (4.5–6.5) × 10³ and polydispersity index below 1.10.

Precise, efficient copolymerizations of ethylene with cyclic olefins [norbornene (NBE), cyclopentene (CPE)] using nonbridged half-titanocenes of type, Cp'TiCl₂(L) (Cp' = cyclopentadienyl group, L = aryloxo, ketimide)-MAO catalyst systems have been summarized. CpTiCl₂(N = C^tBu₂) exhibited both remarkable catalytic activity and efficient NBE incorporation for ethylene/NBE copolymerization: The NBE incorporation by Cp'TiCl₂(X)X = N = C^tBu₂(X)(X = N = C^tBu₂, O-2,6-ⁱPr₂C₆H₃; Cp'=Cp, C₅Me₅, indenyl was related to the calculated coordination energy after ethylene insertion. (^tBuC₅H₄)TiCl₂(N=C^tBu) exhibited significant catalytic activities with efficient CPE incorporations in ethylene/CPE copolymerization in the presence of MAO. The polymerization proceeded with exclusive 1,2-CPE incorporation, affording high molecular weight (alternating) copolymers with uniform distributions. Therefore, the cyclopentadienyl fragment (Cp') plays an essential role in terms of both the activity and the efficient cyclic olefin incorporation.

Convenient synthesis of new methacryloyloxy-substituted phthalocyanines for polymerization reactions, i.e. copper(II) 2,9,16,23-tetra(methacryloxyethoxycarbonyl)phthalocyanine and copper 2,9,16-tris(tert-butyl)-23-(methacryloxyethoxycarbonyl)phthalocyanine, consisting of just a few steps, has been developed. The copolymerization with a dimethacrylate derivative was investigated. The substituted phthalocyanines are interesting materials for ophthalmosurgery in ophthalmology (contact vision correction of eye lenses).

In this review, free-base and metalloporphyrins, functionalized on meso-positions by quaternary pyridinium units, also referred to as cationic porphyrins, are presented. The article consists of five parts. In the first part free-base porphyrins are described, especially taking account on generation of singlet oxygen; next parts concern metalloporphyrins. The second and third parts deal with zinc and manganese porphyrins, respectively; in the fourth part copper, palladium, and platinum porphyrins are presented. In the fifth part, describing porphyrins with various metal ions an attention is paid to porphyrin metal-organic frameworks (MOFs) and metal-organic materials (MOMs) in which metalloporphyrins are immobilized; syntheses and characterization of obtained products are shown.

The methods for the synthesis of porphyrins containing active vinyl groups on a periphery of the tetrapyrrole macroheterocycle are described. The possibility of their usage as comonomers in a copolymerization reaction with methyl methacrylate is given.

Polyaniline, poly(o-bromoaniline) and poly(aniline-co-o-bromoaniline)s have been prepared by chemical oxidative polymerization methods. A series of poly(aniline-co-o-bromoaniline) derivatives has been prepared by the chemical oxidative copolymerization of aniline with different mole ratio of o-bromoaniline by varying the feed ratios of the monomers with the introduction of o-bromoaniline units along the polymer backbone. The morphology of each poly(aniline-co-o-bromoaniline) derivative is observed as a porous network of aggregated nanoparticles with each nanoparticle having smaller nanoflake structures. Room temperature electrical conductivity studies reveal that polyaniline has a conductivity value of the order of 10${}^{-3}$S/cm. However, the corresponding poly(aniline-co-o-bromoaniline), with 10% o-bromoaniline content, shows a fivefold increase of the electrical conductivity relative to the polyaniline homopolymer. The different polymer derivatives were characterized by ¹H NMR spectrometry, Scanning electron microscopy (SEM) and Transmission electron microscopy (TEM) methods, AC conductivity and dielectric permittivity measurements.

Microemulsions are isotropic, transparent or translucent, and thermodynamically stable multicomponent fluids, normally composed of an aqueous component, an amphiphile as surfactant, and frequently a co-surfactant. The microemulsions have unique properties such as low viscosity, high stability, and transparency. Their uniformly dispersed smaller droplets have made them attractive media for polymerization. In this paper, the inverse microemulsion copolymerization kinetics of acrylamide (AM), sodium allylsufonate (SAS), and sodium 4-styrenesulfonate (SSS) initiated by ammonium peroxodisulfate (APS) and sodium bisulfite redox initiators in Span-80/Tween-80 mixture emulsifier system were reported. This study aims to elucidate the copolymerization conversion mechanism in the microemulsion media. The inverse microemulsion copolymerization factors of emulsifiers, reaction time and temperature, and SAS /SSS mass ratio on the copolymer conversion were investigated using gravimetric method. High copolymer materials are achieved, and these additives will apply to modifying working fluids for oil and gas engineering.