This paper deals with some new methods for synthesis of the polymeric semiconductors by conjugated reactions and also with electrophysical properties of the polymers. Elimination of hydrogen halides from α,β-dihalo derivatives by bases (calcium oxide or tertiary amines) yields polymers with conjugated bonds. The reaction proceeds at 200–300°C. under atmospheric or elevated pressures, acetylenes being the intermediates. α,β-Dihalo compounds with calcium carbide above 150°C. produce polyacetylenic copolymers by elimination of two moles of hydrogen halide, also by generating acetylene from calcium carbide. The identical reaction (elimination of water) was observed between carbonyl compounds and calcium carbide. Elimination of water from monoand bifunctional phenols in the presence of zinc chloride under pressure above 200°C. yields polyphenylenes and polyhydroxyphenylenes, dehydrobenzene (benzyne) and hydroxybenzyne being intermediates. The polyhydroxyphenylenes prepared have a degree of polymerization from 4–5 to several thousand and are of interest as intermediates for thermostable resins, inhibitors etc. Linear polycyanamide and polycyanic acid were first prepared by polycondensation of urea with ammonium bicarbonate in the presence of zinc chloride. Analogous polymers were obtained from the ring-opening polymerization of melamine and cyanuric acid. The polymers show good semiconductor and ion-exchange properties. Polycondensation of ketones with ammonium bicarbonate also gave conjugated polymers. Thus, organometallic polymers were prepared from acetyl- and diacetyl ferrocene. We have also studied electrophysical, magnetic, and catalytic properties of the conjugated polymers prepared by the new methods. The electrical conductivity of the best specimens ranged from 10?3 to 10?6 ohm?1 cm.?1; the number of electrons unpaired was 1018–1019 spins/g. 相似文献
In order to determine the stereoregularity of poly(4-vinylpyridine), 4-vinylpyridine-β,β-d2 was synthesized from 4-acetylpyridine. The 1H-NMR spectra of the deuterated and nondeuterated polymers were measured and analyzed. From the 1H-NMR spectra of poly(4-vinylpyridine-β,β-d2), triad tacticity can be obtained, while the 1H-NMR spectra of nondeuterated poly(4-vinylpyridine) give the fraction of isotactic triad. The 13C-NMR spectra of poly(4-vinylpyridine) were also observed, and the spectra of C4 carbon of polymers were assigned by the pentad tacticities. The fraction of isotactic triad of poly(2-vinylpyridine) and poly(4-vinylpyridine) obtained under various polymerization conditions were determined. The radical polymerization and anionic polymerizations with phenylmagnesium bromide and n-butyllithium as catalysts of 4-vinylpyridine gave atactic polymers. 相似文献
Abstract Analytical data and infrared spectral measurements down to 200 cm?1 on the 1:1 compounds formed by the interaction of zinc(II) and cadmium(II) thiocyanates and mercury(II) chloride and bromide with 4-aminomethylpyridine indicate that the compounds are coordination polymers having tetrahedral stereochemistry with bidentate bridging 4-aminomethylpyridine molecules and terminally bonded halogen/pseudohalogen groups in the solid state. 相似文献
The reaction of 1H‐tetrazole‐1‐acetic acid (Htza) and perchloric acid with cuprous chloride with slow evaporation at room temperature gave a novel 3D porous CuII coordination polymer, [Cu2(tza)4] · ClO4 · 4H2O ( 1 ), (tza = tetrazole‐1‐acetate). The structure exhibits an unusual 3D microporous coordination framework built up by four coordinated CuII nodes and bidentate bridging tza ligands with lvt‐type topology. Furthermore, the magnetic properties of complex 1 were also investigated. 相似文献
Recently, metal-coordinated orthogonal self-assembly has been used as a feasible and efficient method in the construction of polymeric materials, which can also provide supramolecular self-assembly complexes with different topologies. Herein, a cryptand with a rigid pyridyl group on the third arm derived from BMP32C10 was synthesized. Through coordination-driven self-assembly with a bidentate organoplatinum(II) acceptor or tetradentate Pd(BF4)2•4CH3CN, a di-cryptand complex and tetra-cryptand complex were prepared, respectively. Subsequently, through the addition of a di-paraquat guest, linear and cross-linked supramolecular polymers were constructed through orthogonal self-assembly, respectively. By comparing their proton nuclear magnetic resonance (1H NMR) and diffusion-ordered spectroscopy (DOSY) spectra, it was found that the degrees of polymerization were dependent not only on the concentrations of the monomers but also on the topologies of the supramolecular polymers. 相似文献
1,1-Dichloro-2-vinylcyclopropane ( Ia ), 1,1-dichloro-2-methyl-2-vinylcyclopropane ( Ib ), 1,1,2-trichloro-2-vinylcyclopropane ( Ic ) were prepared from the corresponding dienes and chloroform in the presence of a phase transfer catalyst (PTC), R4N+Cl?. Monomers Ia – Ic underwent a clean 1,5-type radical ring-opening process to afford the corresponding polymers in good yield. Further, the relative rate of polymerization and reaction of ( I ) with thiophenol were studied. 相似文献
The radiation-induced polymerization of acrylonitrile in the frozen aqueous solutions of various metal chlorides and zinc halides was studied to compare the accelerating effect of metal cations and halogen anions. Among metal chlorides examined, zinc, stannous, manganese, and nickel cations gave greater rates and degrees of polymerization. Of the halogen anions, the rate of polymerization decreased in the order, Br?, CI?, SCN? ? I?, CH3CO2?, and the degree of polymerization decreased in the order, Br?, SCN? ? CI? ? I? ? CH3CO2?. The increase of the rate and the degree of polymerization was confirmed below the eutectic temperatures of the hydrated metal chlorides and ice. This suggests that the increment of the rate and the degree of polymerization is attributed to formation of hydrated metal chloride-acrylonitrile complexes accompanied by their solidification in eutectic mixtures with ice. The radioactivation analysis of polymers obtained in frozen dilute aqueous zinc bromide solution reveals appreciable contribution of water to generation of initiating species. 相似文献
Dialkylzinc–Lewis base systems are found to be active catalysts for the polymerization of alkylene oxides. The diethylzinc–dimethyl sulfoxide system is especially effective in the preparation of high polymers of ethylene oxide and propylene oxide. Diethylzine does not react with dimethyl sulfoxide, but there is strong association between the compounds. The proton magnetic resonance spectrum of a poly(ethylene oxide) prepared by the catalyst system suggests that the n-butoxyl group is attached to the end of the polymer chain. Polymerization of ethylene oxide seems to be initiated by the ethyl–zinc bond. The active species of the system seems to be diethylzinc coordinated with dimethyl sulfoxide. The efficiency of the catalyst system for the formation of high molecular weight polymer is 10?1?10?2. The other part of the catalyst is responsible for the formation of low polymers. 相似文献
The syntheses of two new pyrene-containing monomers—2-(1-pyrenyl)methyl-2-oxazoline ( 6 ) and methyl 2-(1-pyrenyl)acetamidopropenoate ( 12 )—and their polymerization are described. Cationic isomerization polymerization of 6 with ethylene glycol ditosylate initiator gave poly[N-(1-pyrenyl)acetyl ethylenimine] ( 7 ) and free-radical polymerization of 12 with AIBN initiator gave poly[methyl 2-(1-pyrenyl)acetamidopropenoate] ( 15 ). The monomer model compounds of the two polymers, namely, N,N-diethyl(1-pyrenyl)acetamide ( 9 ) and methyl 2-methyl-2-(1-pyrenyl)acetamidopropanoate ( 14 ), were also synthesized. The polymers were characterized by elemental analysis, IR spectroscopy, and a comparison of their 1H-NMR spectra with those of the respective monomer model compounds. 相似文献
The formation of “guest-host” complexes from dimeric zinc octaalkylporphyrinates with a poly(ethyleneoxy) bridge and various
bidentate ligands containing two N atoms was studied by spectrophotometric titration and 1H NMR spectroscopy in toluene-methanol (5: 1). The reactions of dimeric porphyrinates with 1,4-diazabicyclo[2.2.2]octane and
1,4-diazine gave 1: 1 or 1: 2 complexes, depending on the molar ratio of metal porphyrin and the ligand. The stability constants
of the complexes obtained and the concentration ranges for their formation were determined. 相似文献
Novel organoarsenic polymers, poly(vinylene-arsine)s, were synthesized by a free-radical alternating copolymerization of phenylacetylene with cyclooligoarsines as an atomic biradical equivalent. The polymerization between pentamethylpentacycloarsine (1a) or hexaphenylhexacycloarsine (1b) with phenylacetylene (2) in the presence of a catalytic amount of AIBN (in benzene; refluxing; for 12 h) gave the corresponding poly(vinylene-arsine)s. The obtained polymers were soluble in common organic solvents such as THF, chloroform, and benzene. From gel permeation chromatographic analysis (chloroform, PSt standards), the number-average molecular weights of the polymers from 1a and 1b were found to be 11500 and 3900, respectively. The structures of the polymers were supported by 1H and 13C NMR spectroscopies. The corresponding polymer was also obtained by irradiation of a benzene solution of 1a and 2 with xenon lamp at room temperature. After the polymer from 1a was stirred vigorously with 30% H2O2, the 1H NMR spectrum of the polymer showed the methyl proton that was assigned to As(III)-Me, suggesting the insensitivity of the trivalent state arsenic in the main chain to the oxidation. The structures and the molecular weights of the polymers were insensitive to the feed ratio of the monomers. This result indicates that the addition of the arsenic radical to phenylacetylene was a rate-determining step in the copolymerization. 相似文献
Some classes of organometallic catalysts what induce stereospecific polymerization of methacrylonitrile have been found. They include organolithium aluminum compounds of the type LiAlR4, Li[R3AlOAlR2], and Li[R3AlN(R)AlR2], organosodium aluminum compounds of the type NaAlR4, organolithium zinc compounds of the type LiZnR3 and Li2ZnR4, organomagnesium aluminum compounds of the type RMg[AlR4] and Mg[AlR4]2, and organomagnesium compounds containing an Mg? N bond, such as and their related compounds. One of the features of the polymerization with these catalysts was that the crystalline polymers were formed at moderately high temperatures. Total conversion, solubility index, and molecular weight of the polymer increased with increasing polymerization temperature, as observed in the case of polymerization with diethylmagnesium catalyst. Catalysts with an Mg? N bond were found to be highly effective for the stereospecific polymerization. The acetone-insoluble fractions of the polymers gave x-ray diagrams identical to the crystalline polymer produced with diethylmagnesium. This indicates that the acetone-insoluble crystalline polymers produced with these catalysts have an isotactic structure. The viscosity–molecular weight relationship for crystalline polymer was conveniently determined in Cl2CHCOOH at 30°C.; [η] = 2.27 × 10?4M0.754. 相似文献
Abstract Zinc (II) was selectively extracted from aqueous solutions of pH 7.8–8.5 into chloroform with N-p-methoxyphenyl-2-furylacrylohydroxamic acid (MFHA). 1-(2-pyridylazo)-2-naphthol (PAN) or 2-[(5-nitro-2-pyridyl)azo]-1-naphthol (NPAN) were added to the extract to form intensely coloured ternary complexes measurable spectrophotometrically at 550 nm (? = 6.03 × 104 1 mol?1 cm?1) and 625 nm (? = 8.15 × 104 mol?1 cm?1) respectively. For atomic absorption spectrometric analysis, methyl isobutyl ketone (MIBK) was used as extracting solvent instead of chloroform and the zinc-MFHA-MIBK extract was aspirated directly into an air-acetylene flame. The absorbance was measured at the 213.9 nm resonance line with a detection limit of 0.05 ppb, which was significantly better than the limit of 1.0 ppb achieved for zinc previously with flame AAS. The method tolerated a large number of anions and cations normally occurring with zinc in environmental samples, and was applied to the trace analysis of zinc in alloys, coal, plant tissues, animal tissues and natural waters. The combinations of MFHA and PAN/NPAN were chosen from eleven hydroxamic acids and nine pyridylazo reagents as detailed in the paper. 相似文献
The synthesis of optically active p-sec-butylstyrene (I) has been carried out starting with (S)-2-phenylbutane (II) having optical purity 88–91%. The optical purity of I thus obtained was found to be 73–75%. The polymerization of I with stereospecific coordinated anionic catalysts gave amorphous polymers, as in the case of many other p-substituted styrene derivatives. The fractions obtained from these polymers have very similar rotatory power at 589 nm which is practically equal to that of polymer of I obtained by nonstereospecific radical initiator and of low molecular weight structural models. Accordingly the 1Lb electronic transition of the aromatic chromophore shows a very low rotatory strength in all samples examined. This result is related to the lack in solution of conformations with a predominant single chirality of the main chain of the macromolecules derived from I. 相似文献