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13C-NMR. Studies on Ion-Selective Liquid Membranes. A method for the 13C-NMR. study of solvent polymeric membranes in equilibrium with aqueous salt solutions is described. Neutral ion carriers incorporated in these membranes maintain a high degree of rotational mobility. The complexation by group IA and IIA cations of macrotetrolide antibiotics as well as of carriers of the type 3,6-dioxa-octanedioic diamides in the membrane phase was followed by 13C-NMR. chemical shift and spin-lattice relaxation studies. 相似文献
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Investigation of the interaction of neutral carriers with ions in membranes by 13C-NMR. and EMF.-measurements. Applying a simple model, information on the interaction of neutral carriers with cations as well as on the ion pair formation may be obtained through 13C-NMR. and potentiometric studies of PVC-supported ion selective liquidmembranes in contact with aqueous solutions. The results indicate that carriers for K+ (nonactin) and synthetic ionophores for Ca2+ show an association of the carrier-complexes with lipophilic anions. The extent of complex formation of the carrier in the presence of lipophilic anions in the sample solution is in agreement with earlier interpretations of the anion interference of cation selective liquid-membrane electrodes. 相似文献
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13C-NMR. Substituent Increments of the Azido-group in 1,4-Benzoquinones The empirical substituent increments of the azido-group in 1,4-benzoquinones have been derived from the 13C-NMR. chemical shifts of 2-azido-5-chloro-1,4-benzoquinone. The validity of the obtained values was tested by comparison of the empirical and computed 13C-NMR. chemical shifts of other azido-chloro-1,4-benzoquinones. 相似文献
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About the Availability of 13C-NMR Substituent Increments in 1,4-Benzo- and 1,4-Naphthoquinones The 13C-NMR spectra of a number of substituted 1,4-benzo- and 1,4-naphthoquinones have been obtained and assigned. Effects of CH3-, O-alkyl-, Cl-, NH2- and N3- substituents have been deduced for the quinoid part of the molecules and used for the calculation of 13C-chemical shifts. 相似文献
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1H- and 13C-NMR. Spectroscopy of the Nonadrides The 1H- and 13C-NMR. spectra of the nonadrides glaucanic acid ( 1 ), glauconic acid ( 2 ), heveadride ( 3 ), byssochlamic acid ( 4 ), scytalidin ( 5 ), rubratoxin A ( 6 ), and rubratoxin B ( 7 ) have been measured. Partial decoupling experiments permitted assignment of the majority of the signals. 相似文献
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《Tetrahedron letters》1988,29(8):921-924
1,3-Diazabutadienes react with diphenylketene in [2+2] - and [4+2] cycloaddition reactions, depending on the substitution pattern. Spectroscopic data (IR, 1H- and 13C-NMR) and results of quantummechanical model calculations (ab initio 3-21G) are presented. 相似文献
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Chun-qing Liu Yang Liu Zhong-rong Shen Ping Xie Rong-ben Zhang Chao-bin He Tai-shung Chung 《高分子科学》2001,(1):97-102
A novel alcohol-soluble polyorganosiloxane containing amino side groups, poly[3-(4-aminophenoxy)propylmethylsiloxane] (2), was first prepared by the reduction of nitro groups on 4-nitrophenoxypropyl side chains of poly[3-(4-nitrophenoxy)propylmethylsiloxane] (1). The reaction proceeded easily with nearly 100% conversion. The synthesized alcohol-soluble polymer 2, which has potential application as a precursor for preparing advanced functional polymers, was characterized by FTIR 1H-NMR, 13C-NMR, 29Si-NMR, VPO and GPC, respectively. 相似文献