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101.
Hiroyuki Nishide Naoki Yoshioka Yukoh Saitoh Ritsuko Gotoh Takeshi Miyakawa Eishun Tsuchida 《高分子科学杂志,A辑:纯化学与应用化学》2013,50(9):775-786
Abstract m- and p Bis(diphenylene)propenylphenylacetylene (m-, p-8) were synthesized and polymerized with WCI6, MoCl5, and Rh catalyst, yielding solvent-soluble poly(phenylacetylene)s bearing a π-conjugated bis(di-phenylene)propenyl groups (m-, p-7a). The polymers gave their polyanion derivatives, which were electrolytically and chemically oxidized to yield the corresponding polyradicals (m-, p-7b). The polyradicals were chemically very stable due to the resonance stabilization of an unpaired electron whose spin concentration could be increased up to ca. 2 × 1023 spins per molar monomer unit. ESR spectroscopy suggested an antiferro-magnetic interaction between unpaired electrons. 相似文献
102.
Sugimoto T Bamba T Izumi Y Nomura H Shiina T Fukusaki E 《Journal of separation science》2011,34(24):3587-3596
This study sought to develop techniques for LC/MS-based metabolomics and to verify that an MS/MS spectral tag (MS2T) could be used in practical secondary metabolite profiling. The retention time (RT), precursor ions, and fragment ions generated by nozzle-skimmer fragmentation were determined using ultra-performance liquid chromatography/time-of-flight mass spectrometry (UPLC/TOF-MS) and compared with the MS2T. A standard mix was analyzed with UPLC/TOF-MS under the same conditions as were used to construct the MS2T. The difference in RT for the standards was less than 0.15 min and the average RSD was about 2.8%, suggesting that the analysis was highly repeatable. Both precursor ions and fragment ions were observed when the cone voltage was 75 V. Experimental data and fragmentation pattern in the MS2T annotation list were highly similar. Wild-type and cas-1 mutant Arabidopsis thaliana samples treated with an elicitor were analyzed using UPLC/TOF-MS. Sixty-five peaks were successfully annotated. Fragment ions were observed with nozzle-skimmer fragmentation in 50 of 65 (77%) peaks. The reliability of annotation may have increased as a result of fragment ions. Results of multivariate analysis suggested that cas-1 was related to induction of the biosynthesis of these flavonoids. The devised method facilitated practical secondary metabolite profiling. 相似文献
103.
Amii H Ichihara Y Nakagawa T Kobayashi T Uneyama K 《Chemical communications (Cambridge, England)》2003,(23):2902-2903
N-Allylic difluoroenamines exhibited unusual behaviors under thermal conditions; N-allyl difluoroenamines in refluxing xylene afforded not only aza-Claisen rearrangement products, but also 2-azabicyclo[2.1.1]hexanes, whose formation could be explained via intramolecular [2+2]-cycloaddition, whilst N-prenyl difluoroenamine underwent an ene reaction to give the pyrrolidine as a sole product. 相似文献
104.
[reaction: see text] In the presence of MS 4A in DMSO, cyanobenzoylation of various aldehydes with benzoyl cyanide proceeded very smoothly to give the corresponding cyanohydrin benzoates in high to excellent yields without an acid or a base. On the other hand, reaction of aldehydes with BzCN in DMSO-H(2)O also occurred readily to afford the corresponding free cyanohydrins exclusively. 相似文献
105.
Commercially available powdered photocatalysts such as P-25 are known to show high photocatalytic performance. However, in practical use, their anchoring onto a substrate without any binders is still very difficult. The purpose of this study is to design and develop high-performance photocatalysts that can be anchored onto a substrate, and to this end we have prepared a titanium oxide photocatalyst using a wet process. The results of this study led to the successful development of rectangular column structured titanium oxide crystals which could be anchored onto silica sheets. The rectangular columnar crystal was 100- 500 nm wide and 1000- 5000 nm long. Moreover, investigations on the complete oxidation reaction of acetaldehyde into CO2 and H2O showed a high performance equivalent to that of the most efficient marketed powdered photocatalysts. 相似文献
106.
Yasuyuki Mori Atsushi Sudo Takeshi Endo 《Journal of polymer science. Part A, Polymer chemistry》2019,57(7):792-798
A series of soluble oligo(spiroorthocarbonate)s (OSOCs) were synthesized by polycondensation of tetraethylorthocarbonate with pentaerythritol derivatives. The pentaerythritol derivatives used herein were synthesized from pentaerythritol by attaching substituents on it to improve the solubility of themselves and the resulting OSOCs. The structures of the OSOCs were confirmed by NMR spectroscopy and MALDI‐TOF mass analysis. © 2019 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2019 , 57, 792–798 相似文献
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109.
A column-switching HPLC method employing both octadecylsilica (ODS) and chiral columns with fluorescence detection was developed for the determination of enantiomer of fluoxetine (FLX), an antidepressant drug, in rat plasma. Racemic FLX was derivatized with a fluorescent reagent, 4-(N-chloroformylmethyl-N-methyl)amino-7-nitro-2,1,3-benzoxadiazole (NBD-COCl) or 4-(N-chloroformylmethyl-N-methyl)amino-7-N,N-dimethylaminosulfonyl-2,1,3-benzoxadiazole (DBD-COCl) and the enantiomeric separation of the resultant derivatives was examined on an amylose-based chiral column (CHIRALPAK AD-RH) in the reversed-phase mode. The derivative with NBD-COCl (NBD-FLX) showed a sufficient separation factor (a) and resolution (Rs) compared with that with DBD-COCl. Thus, FLX was derivatized with NBD-COCl and the resultant NBD-FLX was first quantified on the ODS column and then introduced to the CHIRALPAK AD-RH column via a six-port switching valve to examine the enantiomeric ratio. The intra- and inter-day accuracy (97.6-112.7%) and precision (1.47-10.60%) were satisfactory in the range 10-1000 nM FLX and the limit of quantification was approximately 10 nM. The absolute recoveries of FLX with hexane from rat plasma were in the range 87.5-92.2% (n = 3). The method was applied to determine FLX enantiomers in the plasma of rats administered FLX orally, and it was shown that the R-isomer was eliminated faster than the S-isomer. 相似文献
110.
The present efficient synthesis of [5'-13C]ribonucleosides and 2'-deoxy[5'-13C]ribonucleosides is characterized by the synthesis of the D-[5-13C]ribose derivative as an intermediate via the Wittig reaction of 4-aldehydo-D-erythrose dialkyl acetals with Ph3P13CH3I-BuLi to introduce the 13C label at the 5-position of a pentose. This was followed by the highly diastereoselective osmium dihydroxylation for the preparation of 2,3-di-O-benzyl-D-[5-13C]ribose dialkyl acetal and the cyclization from D-[5-13C]ribose dialkyl acetal derivatives to the alkyl D-[5-13C]ribofuranoside derivative by the use of LiBF(4). The obtained D-[5-13C]ribose derivative was converted into [5'-13C]ribonucleosides and subsequently into the corresponding 2'-deoxynucleosides. 相似文献