杯芳烃钕/二正丁基镁/六甲基磷酰胺催化4-乙烯基吡啶的均聚及其与苯乙烯的共聚

聚4-乙烯基吡啶[P（4-VP）]是一种功能高分子,由于在吡啶环上有一个碱性的氮原子,它能进一步与酸反应生成各种盐,与卤代烃生成季铵盐以及与金属离子生成配合物,可用作高分子电解质,高分子试剂,高分子功能材料等,因此有不少文献对它的合成进行了报道,合成聚4-乙烯基吡啶及其与苯乙烯（St）的共聚物,除了用丁基锂作引发剂外,过渡金属的Ziegler-Natta催化剂,以及烷基铝和烷基锌等也常被用作催化剂,但用这些催化剂催化所得的聚4-乙烯基吡啶及其与苯乙烯的共聚物产率低,分子量小。     

Fabrication of Poly（4-vinylpyridine） Nanofiber and Fluorescent Poly（4-vinylpyridine）/Porphyrin Nanofiber by Electrospinning

Poly（4-vinylpyridine）（P4-VP） nanofiber and fluoresent poly（4-vinylpyridine）/porphyrin（P4-VP/TPPA） nanofiber were respectively prepared by electrospinning. The effect of the concentration of P4-VP/dimethylformamide （DMF） electrospinning solutions on the morphology of P4-VP nanofiber was investigated and it was found that the average diameter of the nanofiber of P4-VP/DMF increased with the increase of the concentration of the spinning solution. After the addition of TPPA to the P4-VP/DMF spinning solution, the diameter of P4-VP/TPPA nanofiber became even due to the increase of the conductivity of the P4-VP/DMF-TPPA solution. The photoluminescent（PL） spectral analysis indicates that the emission peak position of P4-VP/TPPA nanofiber is almost the same as that of pure TPPA at about 650 nm without peak shift, and when it was stored for 20 days, the emission peak of P4-VP/TPPA nanofiber is also at 650 nm, indicating that the fluorescent property of P4-VP/TPPA nanofiber is stable. Fourier-transform iufrared（FTIR） spectrum confirms the chemical composition of the resulting P4-VP/TPPA composite nanofiber.     

One-pot three-component synthesis of 1,4-disubstituted 1H-1,2,3-triazoles using green and recyclable cross-linked poly(4-vinylpyridine)-supported copper sulfate/sodium ascorbate in water/t-BuOH system

Cross-linked poly(4-vinylpyridine)-supported copper sulfate, [P₄-VP]CuSO4 as a green and recyclable, heterogeneous catalyst in the presence of sodium ascorbate (NaAsc), is reported for the regioselective synthesis of 1,4-disubstituted-1,2,3-triazoles from benzyl halides, sodium azide and terminal alkyne in water/t-BuOH (1/1:V/V) at 70 °C. Various alkyl halides and benzyl halides, with electron-withdrawing groups as well as electron-donating groups, were used for synthesis of various 1,4-disubstituted-1,2,3-triazoles in high yields. The present procedure offers as short reaction time and simple reaction work up. This catalyst can be recovered by simple filtration and recycled several consecutive runs without any loss of its efficiency.     

Polymerization of 4-vinylpyridine with acylating agents

The reaction of 4-vinylpyridine (4-VP) with acylating agents in diethyl ether was investigated. Acetyl chloride (AcCl) and trifluoroacetic anhydride [(TFAc)₂O] yield colored oligomers with 4-VP, denoted P-4VP—AcCl (III) and P-4VP—(TFAc)₂O (IV). Nuclear magnetic resonance spectrometry was used to analyze these products. A structure (XII), representing a random copolymer resulting from 1,2-polyaddition and 1,6-polyaddition to 4-VP, is proposed for III and IV. Alternative mechanisms which explain these observations are discussed. Acetic anhydride (Ac₂O) does not acylate 4-VP. It is proposed that this result is caused by the inability of Ac₂O to quaternize 4-VP as an initial step leading to polymerization.     

Etude de la nature des especes ioniques intervenant au cours de la polymerisation anionique de la vinyl-4 pyridine

Initiation of anionic polymerization of 4-vinyl-pyridine (4-VP) in tetrahydrofuran solution, using organo-metallic compounds of Na and K, involves the same type of side reactions as the polymerization of 2-vinyl pyridine (2-VP). The living polymers of 2- and 4-VP have similar u.v. spectra. The values of the dissociation constants of ionic species of 2- and 4-VP are similar when the chain [poly(styrene-b vinyl-4 pyridine)] contains one 4-VP unit (K_n ≈ 10^?9). But when the size of 4-VP block increases, the conductivity goes up to the value observed for living polystyrene (K_D ≈ 10^?7). This phenomenon could be due to a solvation of the counter-ion by the poly 4-vinyl pyridine chain, acting as a polydentate complexing agent.     

Effects of metal salts on polymerization. Part III. Radical polymerizabilities and infrared spectra of vinylpyridines complexed with zinc and cadmium salts

Radical polymerization of 4-vinylpyridine (4-VP), 2-vinylpyridine (2-VP), and 2-methyl-5-vinylpyridine (MVP) was studied in concentrated DMF solutions of ZnCl₂, ZnBr₂, ZnI₂, Zn(CH₃COO)₂, and Cd(CH₂COO)₂ at 50°C. Polymerization of 4-VP and MVP was accelerated by the addition of the metal salts, while the polymerization of 2-VP was greatly retarded. The sequence of the accelerating effect of metal salts for 4-VP was in the following order: Cd(CH₃COO)₂ > ZnCl₂ > Zn(CH₃COO)₂ > ZnBr₂ > ZnI₂. This sequence is almost the same as that reported in a previous report for MVP. However, the order was reversed for the retarding effect on the polymerization of 2-VP. At the intermediate concentration of metal salts, polymerization of 4-VP proceeded heterogeneously, which was explained by considering crosslinking of poly-4-VP by the metal ion. Since a linear correlation between the rate R_p and the degree of polymerization was observed for the 4-VP–Zn(CH₃COO)₂ system, the accelerating effect was postulated to be due to the enhancement in k_p. Results of copolymerization of VP with styrene as M₂ in a concentrated solution of Zn(CH₃COO)₂ indicated the strong activation of 4-VP by complex formation (r₁ = 2.7 ± 0.5, r₂ = 0.08 ± 0.03), whereas the change in the monomer reactivity of MVP is smaller (r₁ = 2.0 ± 0.2, r₂ = 0.35 ± 0.05). The behavior of 2-VP was abnormal (r₁ = 3.35 ± 0.3, r₂ = 0.55 ± 0.15, then r₁r₂ > 1), which was attributed to the steric effect by complex formation. Solid complexes formed between pyridine, 4-VP, 2-VP, or MVP and zinc salts were prepared as samples for infrared spectroscopy. The shifts in infrared absorption bands of these amines were studied by comparing the infrared spectra of the amines before and after the complex formation, and the results were interpreted in terms of electronic as well as steric interactions of metal salts with ligands. Conjugation of the metal salt with the ligand π-orbitals was necessary to explain both infrared spectra and polymerization results.     

Effects of metal salts on polymerization. Part VII. Radical polymerization and spectra of vinylpyridine in the presence of cobaltous chloride

The radical polymerizability of vinylpyridines in the presence of cobaltous chloride was studied in DMF solution, and the results were correlated with the spectroscopic data obtained for methanol solution. In general, the behavior of vinylpyridine complexed with cobaltous chloride is qualitatively the same as that of zinc complexes reported previously. The rates of polymerization were enhanced by the addition of cobaltous chloride when 4-vinylpyridine(4-VP) or 2-methyl-5-vinylpyridine(MVP) was the monomer, whereas the polymerization of 2-vinylpyridine(2-VP) was retarded by cobaltous chloride. The monomer reactivity of all the vinylpyridines was also enhanced by complex formation as studied by copolymerization with styrene. The enhancement of reactivity of 4-VP complexed with cobaltous chloride is somewhat smaller than that of the corresponding zinc complex.     

Rapid and facile synthesis of acyl azides from acyl halides using a polymer-supported azide ion under heterogeneous conditions

In this article a rapid and facile method for synthesis of acyl azide is described. The cross-linked poly(N-methyl-4-vinylpyridinium) azide ion, [P₄-VP]N₃ is prepared and used as an efficient polymeric reagent for synthesis of acyl azides from acyl halides at room temperature under heterogeneous conditions. Various benzoyl halides, with electron-withdrawing groups as well as electron-donating groups, were transformed into the corresponding benzoyl azides in high to excellent yields in short reaction times. The acyl azide products were characterized by FT-IR, and some of them were also characterized by ¹H-and/or ¹³C-NMR spectroscopy, and physical properties were compared to literature values of known compounds. The spent polymeric reagents can be regenerated and reused for several times without losing their activity. Relative to the reported methods, the present method has the advantages of operational simplicity, mild reaction conditions, fast reaction rates, simple reaction work-up and lower hazardous and potentially explosive nature. Also the present method is the first procedure for the synthesis of acyl azides from acyl halides by using a polymer-supported azide ion under heterogeneous conditions.     

4-乙烯基吡啶-氯化锌络合物与电子给体单体光照下共聚合研究

受电子单体4-乙烯基吡啶-氯化锌络合物(4-VP)_2ZnCl_2(M_1)可以和电子给体单体如苯乙烯(M_2)在365nm光照下共聚合。聚合是二者形成的基态电荷转移复合物(CTC)吸收光后产生自由基引发的。测得竞聚率为r_1=2.04,r_2=0.23。对溶剂极性的影响和(4-VP)_2Znal_2与其它电子给体单体光照下共聚合也作了研究。     

邻苯二甲酸-乙酸铜分子印迹聚合物识别性能的研究

以邻苯二甲酸与乙酸铜的配合物为模板, 在甲醇溶剂中制备印迹聚合物, 对其色谱保留行为及结构类似物的识别性能进行了研究. 结果表明, 在甲醇溶液中, 该印迹聚合物不仅能够区分模板分子的结构类似物, 而且对配合物的金属阴、阳离子都具有很好的识别作用. 以邻苯二甲酸为模板制备的聚合物对模板分子本身的保留较弱, 但对模板与铜的配合物却表现出了很强的保留值, 在此从结构分析的角度给出了解释.     

Antibacterial activities of polystyrene-block-poly(4-vinyl pyridine) and poly(styrene-random-4-vinyl pyridine)

Styrene was polymerized in the presence of benzoyl peroxide (BPO) and 2,2,6,6-tetramethyl-1-piperidinyloxy (TEMPO) to yield polystyrene-TEMPO (PS-TEMPO) macroinitiator. The PS-TEMPO macroinitiator with different molecular weight was reacted with 4-vinyl pyridine (4-VP) to synthesize polystyrene-block-poly(4-vinyl pyridine) (PS-b-PVP), which was then quaternized with n-octyl iodide. Antibacterial activity of the quaternized copolymers was assessed against a gram negative bacterium (Pseudomonas aeruginosa) and a gram positive one (Staphylococcus aureus) by using the shake flask test method, and the results were compared with those of poly(styrene-random-4-vinyl pyridine) (P(ST-r--VP)). The quaternized copolymers inhibited greatly the growth of the bacteria, and PS-b-PVP was more active than P(ST-r-VP), which was ascribed to the fact that the content of quaternized 4-VP units on the surface of the particles of the former copolymer was higher than that corresponding to the latter one.     

P(4-VP) based nanoparticles and composites with dual action as antimicrobial materials

Polymeric 4-VP (p(4-VP)) particles were synthesized in an oil-in-water microemulsion system using various amounts of ethylene glycol dimethacrylate (EGDMA) as crosslinker. The prepared p(4-VP) particles were chemically modified to obtain positively charged particles as polyelectrolytes. Furthermore, these p(4-VP) particles were used for in situ Ag and Cu metal nanoparticle syntheses to provide dual action with an additional advantage as bactericidal particles. The synthesized p(4-VP) particles with positive charges and metal constituents were tested for potential antibacterial action against various bacteria such as Staphylococcus aureus ATCC6538, Pseduomonas aeruginosa ATCC9027, Bacillus subtilis ATCC6633, Escherichia coli ATCC8739. It was found that p(4-VP) particles, especially the positively charged forms had potential as antibacterial materials. The synthesized particle dimensions were characterized with TEM, and DLS measurements. Chemical modification of the particles was confirmed by FT-IR spectroscopy and zeta potential measurements, and the metal nanoparticle contents were determined with thermogravimetric (TGA) studies.     

Effect of metal salts on polymerization. Part I. Polymerization of vinylpyridine initiated with cupric acetate

The polymerization of vinylpyridine initiated by cupric acetate has been studied. The rate of polymerization was greatly affected by the nature of the solvent. In general polar solvents increased the rate of polymerization. Polymerization was particularly rapid in water, acetone, and methanol. The initial rate of polymerization of 4-vinylpyridine (4-VP) in a methanol–pyridine mixture at 50°C. is R_p = 6.95 × 10^?6[Cu¹¹]^1/2 [4-VP]² l./mole-sec. The activation energy of initiation by cupric acetate is 5.4 ± 1.6 kcal./mole. Polymerization of 2-vinylpyridine and 2-methyl-5-vinylpyridine with the same initiator was much slower than that of 4-VP. Dependence of R_p on monomer structure and solvent is discussed. Kinetic and spectroscopic studies led to the conclusion that the polymerization of 4-VP is initiated by one electron transfer from the monomer to cupric acetate in a complex having the structure, (4-VP)₂Cu(CH₃COO)₂.     

Synthesis of polymer-supported Fe3O4 nanoparticles and their application as a novel route for the synthesis of imidazole derivatives

Research on Chemical Intermediates - Cross-linked poly(4-vinylpyridine) supported Fe3O4 nanoparticles, abbreviated as [P4-VP]-Fe3O4NPs, were easily prepared as a new magnetic polymeric catalyst and...     

丹酚酸A分子印迹聚合物制备及识别性能研究

以丹酚酸A为模板分子,丙烯酰胺(AM)、α-甲基丙烯酸(MAA)、2-乙烯基吡啶(2-VP)和4-乙烯基吡啶(4-VP)为功能单体,乙二醇二甲基丙烯酸酯(EGDMA)为交联剂,丙酮、乙酸乙酯、乙腈和甲醇为致孔剂,采用本体聚合法制备了一系列丹酚酸A分子印迹聚合物.通过静态平衡吸附实验和选择性实验考察了印迹聚合物的吸附性能...     

Miscibility of poly(vinyl chloride) with ethyl acrylate 4-vinyl pyridine copolymers

Blends (50:50, w:w) of poly(vinyl chloride) (PVC) and poly(ethyl acrylate-co-4-vinyl pyridine) (PEA–4-VP) of different 4-VP contents (2–14 mol %) were prepared. These were found to be partially miscible as evidenced by the presence of a single, through broad, tangent δ peak obtained from torsion pendulum experiments. Several possible types of interactions which might exist between PVC and PEA-4-VP, such as ion-dipole, crosslinking, charge transfer, hydrogen bonding, and dipole–dipole interactions, were explored. From ultraviolet, conductance, infrared, and solubility studies, it was shown that hydrogen bonding or dipole–dipole (or possibly a combination of the two) interactions were the most likely in this system. These interactions have been suggested previously for other systems by various investigators.     

Diphosphine derivatives: Part 5. Ligand behaviour and vibrational spectra of coordinated tetraalkyl-1,2-dithioxodi-λ5-phosphanes (tetraalkyldiphosphine disulphides)

Vibrational data are reported for complexes of tetraethyl-,tetrapropyl-and tetrabutyl-1,2-dithioxodi-λ⁵-phosphanes (tetraalkyldiphosphine disulphides) P₂R₄S₂ with zinc, cadmium, mercury and cobalt halides. The P—P stretching frequencies in the coordinated ligands occur near 500 cm^?1, substantially higher than in the corresponding P₂Me₄S₂ complexes, most probably because of interactions with P—C—C deformation modes. In the F—C stretching region the spectra of the P₂Et₄S₂ complexes are consistent with (but do not necessarily prove) cis-chelate ligand geometry with Zn, Cd and Co halides, and gauche-chelate geometry with Hg halides. No M—S stretching vibrations can be identified above 250cm^?1.     

Formation of unsaturated C3 hydrocarbons by the protolysis of magnesium sesquicarbide with ammonium halides

The protolysis of magnesium sesquicarbide, Mg2C3, with inorganic acids provides an interesting alternative to the more common hydrolysis of ionic carbides for obtaining their respective hydrocarbons. In particular, protolysis reactions with ammonium halides as precursors for hydrogen halides were investigated using in situ methods such as TGA/sDTA/MS and high-temperature XRPD. The protolysis reactions with NH4F and NH4Cl revealed two different reaction mechanisms yielding C3H4 and the respective magnesium halides as expected products. In the case of NH4Cl, intermediate phases that have not been previously observed, specificly (NH4)2MgCl4 (I4/mmm) and two modifications of NH4MgCl3 (P63/mmc), were structurally characterized.     

Pressure-induced formation of molecular B2X4(μ-X)2 (X = Cl, Br, I) species

Boron(III) halides (BX(3), where X = F, Cl, Br, I) at ambient pressure conditions exist as strictly monomeric, trigonal-planar molecules. Using correlated ab initio calculations, the three heavier halides (X = Cl, Br, I) are shown to possess B(2)X(4)(μ-X)(2) local minima, isostructural with the diborane molecule. The calculated dissociation barrier of the B(2)I(4)(μ-I)(2) species [≈14 kJ/mol with CCSD(T)/cc-pVTZ] may be high enough to allow cryogenic isolation. The remaining dimer structures are more labile, with dissociation barriers of less than 6 kJ/mol. All three dimer species may be stabilized by application of external pressure. Periodic density functional theory calculations predict a new dimer-based P1 solid, which becomes more stable than the P6(3)/m monomer-derived solids at 5 (X = I) to 15 (X = Cl) GPa. Metadynamics simulations suggest that B(2)X(4)(μ-X)(2)-based solids are the kinetically preferred product of pressurization of the P6(3)/m solid.     

Reduction of nitrobenzene catalyzed by immobilized copper catalyst under carbon monoxide and water

Catalytic activity for reduction of nitrobenzene to aniline (98%) and azobenzene (2%) using a poly(4-vinylpyridine)-immobilized Cu catalyst [Cu(II)/P(4-VP)] under a CO atmosphere in aqueous 2-ethoxyethanol was studied as a function of the various reaction parameters ([Cu], P(CO), T, and nitrobenzene/Cu molar ratio). Reaction rates were first-order in [Cu]_tot over 1.0–12.0?wt.% range and in P(CO) over the 6.8–27.2?atm range. The catalytic activity proved to be non-linear in nitrobenzene/Cu ratio over 41–500 molar ratio range. These results suggest that the rate-limiting step is preceded by reversible coordination of nitrobenzene to a carbonyl–Cu(I) immobilized species. A catalytic mechanism consistent with the data is proposed.