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871.
Asei William Kawaguchi Atsushi Sudo Takeshi Endo 《Journal of polymer science. Part A, Polymer chemistry》2014,52(3):410-416
1,3‐benzoxazine 1 , bearing 4‐pyridyl moiety on the nitrogen atom, was synthesized from p‐cresol, 4‐aminopyridine, and paraformaldehyde. The efficient synthesis was achieved by adding acetic acid to suppress the strong basicity caused by the presence of 4‐aminopyridine derivatives. Upon heating 1 at 180 °C, it underwent the thermally induced ring‐opening polymerization. The resulting polymer was composed of two types of repeating unit, i.e., (1) Mannich‐type one (‐phenol‐CH2‐NR‐CH2‐) that can be expected from the general ring‐opening polymerization of conventional benzoxazines and (2) a typical phenolic resin‐type one (‐phenol‐CH2‐phenol‐) induced by release of 4‐aminopyridine and paraformaldehyde (unit B). Another structural feature of the polymer was that it possessed a benzoxazine moiety at the chain end. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014 , 52, 410–416 相似文献
872.
In articles by Kokalas et al.1,2 studies were made of the interaction of FeCl3 with diisopropyl methylphosphonate (DIMP), diethyl ethylphosphonate (DEEP), and dimethyl methyl phosphonate (DMMP) and structures were proposed for the reaction products. When the reactions are run under much milder conditions, there is much evidence3–5 to support a different mechanism than that proposed by Kokalas and an altogether different structure of the complexes formed. In the structures proposed by Kokalas et al. the iron atom is surrounded by six oxygen atoms and these are the only bonding atoms to the iron. But on the other hand, in donor-acceptor complexes as are formed in chemisorption reactions,3–5 some of these sites are filled by chloride ions and this difference should be ascertained quite easily by far-infrared spectroscopy. It was the purpose of this study to look at the far-infrared data and either further substantiate the structures proposed or to propose new ones. 相似文献
873.
S. Ravy P. A. Albouy S. Megtert R. Moret J. P. Pouget R. Comes 《Phase Transitions》2013,86(1-4):193-210
X-Ray diffuse scattering from a series of examples where the reason for the existence of incommensurable features is fairly well understood, is described. They include in particular non stoichiometric compounds such as [DIPS Φ4(l3)0.76] and such as intercalated graphite RbC24. and quasi one dimensional conductors. A particular emphasis is given on various 1 - D conductors and to the relation of the incommensurability to the characteristics of the electron conduction bands. 相似文献
874.
《Journal of Coordination Chemistry》2012,65(15):2639-2648
The polymeric ligand (BFP) was synthesized by condensation of bisphenol-A, formaldehyde, and piperazine in alkaline medium at 70–80°C. The polymer–metal complexes were synthesized by the reaction of BFP with Mn(II), Co(II), Ni(II), Cu(II), and Zn(II) acetates in 1?:?0.5 (ligand?:?metal) molar ratio. All the synthesized polymers were characterized by elemental, spectral (infrared, 1H-NMR, and UV-Vis), magnetic moment measurements, and thermal (TGA) analysis. The ligand-field and nephelauxetic parameters have been determined from UV-Vis spectra using ligand-field theory. Elemental analyses indicate the association of water with metal for Mn(II), Co(II), and Ni(II), which is also supported by TGA. The antimicrobial activities of the synthesized polymers were studied by agar well diffusion methods against Bacillus subtilis, Bacillus megaterium, Staphylococcus aureus, Escherichia coli, Salmonella typhi, Pseudomonas aeruginosa, and Shigella boydii. The antimicrobial activity and thermal stability of Cu(II)–polymer were higher than the other polymer–metal complexes due to the higher stability constant of Cu(II). 相似文献
875.
B. Lorenz R. Kirmse M. Findeisen K. Schmidt 《Isotopes in environmental and health studies》2013,49(1):125-130
Abstract The reaction of 2-pyridine carboxylic acid (Hpic) with (n-Bu4N)[TcNCl4] and (n-Bu4N)[TcOCl4] in ethanol and methanol, respectively, yields the dinuclear μ-oxo complex [(pic)2NTc-O-TcN(pic)(Hpic)Cl] and the monomeric complex [TcO(pic)2Cl]. Visible and infrared spectroscopy, ESR, 1H-NMR and 99Tc-NMR have been used to characterize the new compounds. The most important field of application for the new compounds synthesized is radiodiagnostics. 相似文献
876.
Encapsulation and Enhanced Luminescence Properties of IrIII Complexes within a Hexameric Self‐Assembled Capsule
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Dr. Shinnosuke Horiuchi Hirotaka Tanaka Prof. Dr. Eri Sakuda Prof. Dr. Yasuhiro Arikawa Prof. Dr. Keisuke Umakoshi 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(49):17533-17537
Encapsulation and luminescence studies of [Ir(ppy)2(bpy)]Cl (ppy=2‐phenylpyridinate, bpy=2,2′‐bipyridine) within a hexameric resorcinarene capsule are reported. One IrIII complex cation was encapsulated within the capsule, as demonstrated by NMR and dynamic light scattering (DLS) studies. The emission color of the IrIII complex was drastically changed from orange to yellow by encapsulation, in contrast with the lack of significant changes in the absorption spectrum. The hexameric capsule effectively hampers the non‐radiative pathway to increase both the luminescence quantum yield and the exited state lifetime. The luminescent properties of the encapsulated IrIII complex depend on the ratio of IrIII complex to the resorcinarene monomer as well as the concentration of resorcinarene monomer owing to the reversible process of self‐assembly of the hexameric capsule. Quenching experiments revealed that the IrIII complex in the capsule was effectively separated from quenchers. 相似文献
877.
Detrimental Ni(0) transfer in Kumada catalyst transfer polycondensation of benzo[2,1‐b:3,4‐b']dithiophene
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Anjan Bedi Julien De Winter Pascal Gerbaux Guy Koeckelberghs 《Journal of polymer science. Part A, Polymer chemistry》2016,54(12):1706-1712
This article deals with the Kumada Catalyst Transfer Polycondensation (KCTP) of 4,7‐dioctylbenzo[2,1‐b:3,4‐b']dithiophene ( BDP‐Oct ) using Ni(II) catalyst or In/cat combination. A combination of MALDI MS, GPC, and 31P NMR spectroscopy is used to reveal the failure of the KCTP of this particular monomer. Intermolecular transfer reactions to monomer appeared to prevent the formation of polymer. This result is remarkable, since isomeric benzo[1,2‐b:4,5‐b']dithiophene polymerizes in a controlled way. The presence of a “non‐aromatic double bond” in annulated monomers is discussed. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016 , 54, 1706–1712 相似文献
878.
879.
Identification of radical structures on 1‐pentamethylbenzyl‐3‐ethylimidazoliumsilver(I)bromide and 1,3‐bis(pentamethylbenzyl)‐4,5‐dimethylbenzimidazoliumsilver(I)bromide exposed to gamma rays: an EPR study
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Yusuf Ceylan Keziban Usta Ahmet Kunduracioglu Ayhan Usta Bekir Cetinkaya 《Magnetic resonance in chemistry : MRC》2016,54(11):864-869
1‐Pentamethylbenzyl‐3‐ethylimidazoliumsilver(I)bromide and 1,3‐bis(pentamethylbenzyl)‐4,5dimethylbenzimidazoliumsilver(I)bromide and their Ag+ complexes were synthesized and their polycrystal forms were produced by recrystallization in dichloromethane/Et2O solvent system. Structural determinations were carried out by 1H NMR and 13C NMR with a Varian 400 NMR system using tetramethylsilane as internal standard and CDCl3 as solvent. The disappearance of acidic N‐heterocyclic carbene proton showed the formation of Ag(I) complexes. Also, elemental analyses were carried out. Electron paramagnetic resonance (EPR) measurements were performed to determine the formed radical structure on the samples irradiated at the room temperature for 72 h by using 60Co‐source with dose rate of 0.680 kGy. The EPR measurements were carried out in the temperature range of 200 K–450 K. Identical radicals were determined on the irradiated compounds. It was observed that the shapes of the spectra of the samples were independent of the temperature but, the resonance line intensities changed linearly with the temperature. Also, it was detected that the free radical on the 1‐pentamethylbenzyl‐3‐ethylimidazoliumsilver(I)bromide is not stable compared to that on the 1,3‐bis(pentamethylbenzyl)‐4,5dimethylbenzimidazoliumsilver(I)bromide. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
880.