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1.
A new kinetic method of analysis based on catalysed reactions is described. The principle is as follows: to a reaction mixture containing the catalyst to be determined and a large excess of one reactant is added the other reactant at a constant rate; the concentration of the second reactant reaches a steady-state value which can be measured to provide a measure of the catalyst concentration. Iodide and osmium were determined in the p.p.b. range by their catalytic effect on the cerium(IV)-arsenic(III) reaction, the cerium(IV) concentration in the steady state being determined photometrically. Mercury(II) and silver(I) prevent the catalytic action of iodide and so can be determined indirectly. L-Cystine was determined in the p.p.m. range by means of its catalytic action on the iodine-azide reaction; the iodine concentration prevailing in the steady state was followed potentiometrically.

Résumé

On décrit une nouvelle méthode d'analyse cinétique, basée sur des réactions de catalyse: on ajoute, à un mélange contenant catalyseur à doser et un réactant en grand excès, l'autre réactant à vitesse constante. La concentration en catalyseur est fonction de la quantité du deuxième réactant nécessaire pour atteindre une valeur constante. Iodure et osmium, en quantité de l'ordre du p.p.b., ont pu être dosés grâce ù leur effet catalytique sur la réaction cérium(IV) -arsenic(III) ; la concentration en cérium(IV) est déterminée par photométrie. Mercure(II) et argent(I) empêchent l'action catalytique de l'iodure et peuvent être dosés indirectement. La L-cystine est dosée grâce à son action catalytique sur la réaction iode-azoture. La concentration en iode est déterminée par potentiométrie.  相似文献   


2.
Thiopyrano[4,3,2-cd]benzofuran 9 possessing benzofuran and methylenethiopyran structures in the molecule was synthesized starting from 1-chloro-4-methoxy-2-nitrobenzene 11. Some reactions (formylation, protonation and catalytic hydrogenation) on 9 were examined. The 2-position of 9 was highly reactive toward electrophilic reagents and the furan ring was readily reduced by catalytic hydrogenation with palladium-charcoal. Thiopyrano[4,3,2-cd]benzofuran 9 has both properties of methylenethiopyran and benzofuran.  相似文献   

3.
A number of cis-9-propenylcarbazoles were synthesized in good yields by isomerization of 9-allylcarbazoles by the action of tert-BuOK in dimethyl sulfoxide. It was established that cis-9-propenylcarbazole is less thermodynamically stable than its trans isomer. It was shown by13C NMR, UV, and IR spectroscopy that the effect of p-π conjugation in cis-9-propenylcarbazole decreases as compared with the trans isomer as a result of the noncoplanarity of the C=C bond and the carbazole ring. See [1] for communication 5. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 340–343, March, 1980.  相似文献   

4.
The uv irradiation of phenanthrene 9, 10-imine has been shown to give 9H-tetrabenzo[a, c, g, i]carbazole as the major photo-product both in argon purged acetone and in dichloromethane. Phenanthrazine, N-9-phenanthrenyl-9-phenanthrenamine and phenanthrene were formed in smaller quantities. 9-Phenanthrenamine was found to be a minor by-product. N-Butylphenanthrene 9, 10-imine yielded under similar conditions phenanthrene and N-butyl-9-phenanthrenamine as the only isolable polycyclic compounds. In the presence of air the substituted imine gave mainly 2-propylphenanthro[9, 10-d]oxazole.  相似文献   

5.
A novel acrylic monomer bearing acridinyl group, acridine-9-N-acrylamide (Ac-9AA) was synthesized from 9-aminoacridine (9AA) and acryloyl chloride in the presence of triethylamine in dry dichloromethane (CCl2) at room temperature. The synthesized Ac-9AA was identified by IR, MS and 1H NMR spectra. Homopolymer of Ac-9AA was obtained using AIBN as a thermal initiator in THF under 65-70 °C and the average molecular weights (Mw) of poly(Ac-9AA) obtained was very low, being in the order of ca. 103. Copolymer of Ac-9AA and acrylamide was synthesized with thermal initiator and poly(Ac-9AA-co-AM) was characterized by the method of IR, UV-vis and DSC. The photophysical behaviors of Ac-9AA and its polymers were explored by recording the fluorescence spectra in solution, solid and film. In addition, the pH and temperature dependence on fluorescence of the water-soluble poly(Ac-9AA-co-AM) were investigated in detail. The results showed that the relative fluorescence intensity of poly(Ac-9AA-co-AM) had an excellent linear response to temperature in the range of 0-60 °C. Moreover, the fluorescence intensity increased continuously from low pH to high pH while the excitation maxima at 388 nm and emission maxima at 400 nm had redshift after the addition of HCl or NaOH, which results from the fact that the predominance of tautomeric forms of Ac-9AA changed at different medium. This investigation may provide a convenient way to prepared multifunctional macromolecule biomaterial bearing aminoacridine to probe pH and temperature in biological system.  相似文献   

6.
The novel 3-nitro-9-oxo-9H-xanthene- and 3-nitro-9-oxo-9H-thioxanthene-l-carboxylic acids 2a–d were prepared by intramolecular acylation of 3-aryloxy- and 3-arylthio-5-nitrophthalic anhydrides 1 (Scheme). The 3-nitro group was readily substituted by O- and S-nucleophiles and halide and azide ions to give a range of 3-substituted thioxanthone derivatives 3 with varied λmax.  相似文献   

7.
The N-oxide 2 of furo[3,2-b]pyridine ( 1 ) was cyanated by the Reissert-Henze reaction with potassium cyanide and benzoyl chloride to give 5-cyano derivative 3 , which was converted to the carboxamide 4 , carboxylic acid 5 , ethyl ester 6 and ethyl imidate 8 . Chlorination of 2 with phosphorus oxychloride yielded 2-9a , 3- 9b , 5- 9c and 7-chloro derivative 9d . Reaction of 9d with sodium methoxide, pyrrolidine, N,N-dimethylformamide and ethyl cyanoacetate afforded 7-methoxy- 10 , 7-(1-pyrrolidyl)- 11 and 7-dimethylaminofuro[3,2-b]pyridine ( 14 ) and 7-(1-cyano-1-ethoxy-carbonyl)methylene-4,7-dihydrofuro[3,2-b]pyridine ( 12 ). Nitration of 2 with a mixture of fuming nitric acid and sulfuric acid gave 2-nitrofuro[3,2-b]pyridine N-oxide ( 15 ).  相似文献   

8.
The reaction of 9- and 7-(2-hydroyethoxymethyl)guanines and some of their derivatives with thionyl chloride inhexamethylphosphorustriamide was investigated. 9- and 7-(2-Chloroethoxymethyl)- and 8-chloro-, 8-bromo-, and 8-mercapto-9-(2-chloroethoxymethyl)guanines were synthesized. The structure of the compounds was confirmed by the UV and ESR spectra.See [1] for Communication 5.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 671–673, May, 1992.  相似文献   

9.
Diethyl 9-octadecene-1,18-dioate was obtained in 87% yield based on 50% theoretical conversion by the olefin metathesis reaction catalyzed by WOCl4-Cp2TiMe2. The Dieckmann condensation of this diester using potassium hydride afforded 2-ethoxycarbonylcyclo-9-heptadecenone, which was converted by hydrolysis and decarboxylation to cyclo-9-heptadecenone (civetone) as a mixture of cis and trans isomers (1.3 : 1) in 54% yield. Also 9-octadecen-18-olide was obtained in 17.9% by the metathesis of oleyl oleate.  相似文献   

10.
A procedure was developed for phase-transfer catalyzed alkylation of 5-hydroxyindolenine and 9"-hydroxy-substituted spiro[indoline-2,3"-naphtho[2,1-b]oxazines] by alkyl halides. New 9"-hydroxy- and 9"-alkoxy-substituted spironaphthooxazines, spirooxazinyloxyacetic acids, and their esters containing substituents with different length of the carbon chain in the indoline moiety were synthesized. The influence of the substituents on the spectroscopic properties of the starting and colored forms and the kinetic characteristics of photochromic transformations of 9"-substituted spironaphthooxazines in solutions and polymeric films was investigated. The bipolar merocyanine forms of spirooxazines were found to produce H-aggregates.  相似文献   

11.
The highly active peptide hormones isolated from pig thyroids – i.e. α-thyrocalcitonin and its sulfoxide, containing 32 amino acid residues – were subjected to sequence studies using chemical and enzymatic methods. On the basis of these studies the following structure was derived for α-thyrocalcitonin: In the α-thyrocalcitonin sulfoxide (designated formerly as β-thyrocalcitonin) the methionine residue is replaced by methionine sulfoxide.  相似文献   

12.
A study was conducted of the complementary base pair interactions between various pairs of electron-donor monomers, electron-acceptor monomers, homopolymers and alternating copolymers selected from the following group: ( 1 ) 9-(2-vinyloxyethyl)adenine; ( 2 ) 1-(2-vinyloxyethyl)thymine; ( 3 ) 1-(2-vinyloxyethyl)cytosine; ( 4 ) 9-(2-maleimidoethyl)adenine; ( 5 ) 6-chloro-9-(2-maleimidoethyl)purine; ( 6 ) 1-(2-maleimidoethyl)thymine; ( 7 ) 1-(2-maleimidoethyl)cytosine; ( 8 ) homopolymer of ( 4 ); ( 9 ) homopolymer of ( 6 ); ( 10 ) alternating copolymer of ( 2 ) and maleic anhydride; ( 11 ) alternating copolymer of ( 2 ) and ( 5 ); and ( 12 ) alternating copolymer of ( 2 ) and ( 4 ). By 1H-NMR, in CDCL3, the base pair interactions between ( 1 ) and ( 2 ) were shown to be hydrogen bonding, the extent of which was shown by a calculated binding constant, K = 61.81 L/mol. The nature of this interaction was conformed by IR. Neither monomer pairs ( 1 )/( 2 ) nor ( 4 )/( 6 ) exhibited hydrogen bonding in DMSO-d6. However, hydrogen bonding interaction was observed for DMSO-d6 solutions of homopolymers ( 8 ) and ( 9 ) and for alternating copolymer ( 12 ). On the basis of an upfield chemical shift of the 2- and 8-aromatic protons of ademine of ( 1 ) in D2O, a partial overlap stacking interaction is proposed. No charge-transfer interactions could be observed by UV between donor-acceptor monomer pairs.  相似文献   

13.
Various polyesters having pendant (9-anthryl)methyl groups were prepared from 2-(9-anthryl)methylpropane-1,3-diol and the esters or chlorides of dicarboxylic acids. These polyesters are poly[2-(9-anthryl)-methylpropane-1,3-diyl-oxy-(9-anthryl)methylmalonyl-oxy](PA-1A), poly-[2-9-anthrylmethylpropane-1,3-diyl-oxysuccinyloxy](PA-2), poly-[2-9-anthrylmethylpropane-1,3-diyl-oxyadipyloxy](PA-4), poly[2-(9-anthryl)methylpropane-1,3-diyl-oxysebacyloxy] (PA-8), poly[2-(9-anthryl)methylpropane-1,3-diyl-oxy-(1-naphthyl)methylmalonyloxy](PA-1N), and poly[2-(9-anthryl)methylpropane-1,3-diyl-oxyterephthaloyloxy](PA-Ph). Although the absorption spectrum of the anthryl group is not influenced by the change in the environment in which the anthryl group is located, the fluorescence spectra show characteristic change reflecting the environment around the chromophore. Dimer, aggregates, or excimer fluorescence of anthryl groups and energy transfer from naphthyl to anthryl groups for PA-1N were discussed. The rates of photodimerization of anthryl groups determined spectroscopically in dilute solutions for these polyesters and their monomer model compound(1,3-diacetoxy-2(9-anthryl)methylpropane) (MA), were in the following order; PA-8 > PA-4 > PA-1A > PA-2 > PA-Ph > MA. The effects of polymer structure on the photoreaction were discussed on the basis of information on molecular interactions obtained by fluorescence spectroscopy. The fraction of intramolecular cyclization was estimated from dependence of the rate of photoreaction on the concentration of the polyesters. When anthryl groups are linked by a long, flexible polymethylene chain (PA-8), intramolecular process predominates whereas intermolecular dimerization proceeds almost exclusively for a rodlike molecule(PA-Ph). These results are discussed from the viewpoint of the structure–functionality relationship in polymeric systems.  相似文献   

14.
The original article to which this Erratum refers was published in Surface and Interface Analysis Vol. 38, No. 9, 2006, pages 1252–1256. Copyright © 2006 John Wiley & Sons, Ltd.  相似文献   

15.
The total synthesis of 9β, 10α-testosterone via a BCD-tricyclic intermediate is described. The latter compound – 17β-hydroxy-des-A-androst-9-en-5-one – was obtained in optically active form by our previously reported scheme, using an efficient resolution step early in the synthesis. New results regarding the asymmetric induction step are also discussed.  相似文献   

16.
The first total syntheses of O-methylcularicine 9b and sarcocapnine 9c are described together with a new synthesis of cularine 9a using the Ullmann condensation reaction of the appropriate 2′-bromo-8-hydroxy-tetrahydrobenzylisoquinoline formed by phase-transfer alkylation of Reissert compound 2. When this strategy was combined with the lead tetraacetate treatment of the tetrahydrobenzylisoquinoline it yielded 4-hydroxycularines, from which highly oxidized members of the family can be obtained. This is exemplified by the first synthesis of 4-hydroxysarcocapnine 19 and its transformation to the 3,4-dioxoisocularine yagonine 20 , rearrangement of which afforded the aristoisocularine aristoyagonine 21.  相似文献   

17.
Wiley‐VCH, Weinheim 2009. 306 pp., hardcover, 129.00 €.—ISBN 978‐3527320370

  相似文献   


18.
The spectrum of 249Bk, excited in an electrodeless lamp, has been recorded between 3700 and 12,000 cm?1 on a Fourier-transform spectrometer. The strongest 90 lines are listed along with the classification for 77 of them. The lowest levels of the 5f96d7s, 5f97s7p, 5f97s8s, 5f86d7s2 , 5f87s27p and 5f86d7s7p configurations of Bk I and of the 5f96d and 5f97p configurations of Bk II have been identified. Lists of the energies and hfs data of the Bk I levels involved in the i.r. transitions are also included.  相似文献   

19.
A passage from deca-1,4,9-triene (I) to (E,E)-dodeca-8,10-dienol (II) in five stages with an overall yield of 23% has been found by the selective transformations of deca-1,4,9-trien-1-yltrimethylsilane. Thus, under mild conditions, by the hydrogenation of (I) with the aid of 9-borabicyclo[3.3.1]nonane (9-BBN) followed by oxidation with H2O2 (E,E)-deca-6,8-dienol was obtained with a yield of 60%, and this was converted quantitatively into the corresponding tosylate. The ethynylation of the latter with lithium acetylide gave (E,E)-dodecadien-1-yne (III) on a Lindlar catalyst followed by the reaction of the resulting triene with 9-BBN, as described above for (I) led to the desired codlemone (II). The IR, PMR,13C NMR, UV, and mass spectra of the compound obtained are discussed.Institute of Chemistry, Bashkir Branch, Academy of Sciences of the USSR, Ufa. Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 514–518, July–August, 1984.  相似文献   

20.
The title compound was prepared from compounds readily obtained from 2-carbomethoxy-I-indanone oxime ( 5 ) or from the N-chlorosulfonyl isocyanate adduct of indene ( 9 ). Apart from its ability to undergo transformation to the azetidine, compound 9 upon refluxing with excess LAII was found to undergo reductive decompostion to cis-2-hydroxymethyl-1-indanamine ( 2 ).  相似文献   

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