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1.
A sensitive and selective spectrophotometric determination of gallium is described. It is based on extraction of gallium from 3 M hydrochloric acid solution as a chloro-complex into 1,2-dichlorobenzene and exchange of the chloro ligand with 4-(2-pyridylazo)resorcinol (PAR); the final association complex of Ga—PAR with tetraphenylarsonium ions is measured in the organic phase. The absorption maximum occurs at 510 nm and the effective molar absorptivity is (8.2 ±0.3) ·1O4 l mol-1cm-1. Beer's law is obeyed over the range 0.2–2 p.p.m. of gallium. Few ions interfere. 相似文献
2.
2-Hydroxy-3-napthoic acid is presented as a new, highly sensitive and selective reagent for its colour reaction with ferric ion. The sensitivity of the reaction is 0.025 μg/cm2 (SANDELL). The blue-coloured complex is maximally absorbed at 590 mμ and obeys Beer's law up to 24 p.p.m. of iron. The optimum range of concentration is from 4 to 20 p.p.m. of iron, where the percent relative analysis error per 1% absolute photometric error is 2.9. The composition of the complex, as evaluated by JOB's method and as verified by the Molar and Slope ratio methods, shows that in solution, the complex contains the iron and the reagent in a ratio of l : 1. The empirical formula of the complex is suggested to be [Fe(C11H7O3)]+2. The molar extinction coefficient is 2212 and the instability constant of the complex is about 4.29 ? 10-4. Coloured ions or those ions that give coloured products are tolerated to a limited extent during the determination of iron. 相似文献
3.
N. K. Moroz Yu. V. Seryotkin I. S. Afanassyev V. V. Bakakin 《Journal of Structural Chemistry》2002,43(4):595-600
The location and diffusive mobility of ammonium ions and water molecules in the channels of the NH4substituted forms of the natural zeolites clinoptilolite (NH4)6.5[Al6.5Si29.5O72] · 12.6H2O and chabazite (NH4)9.6Ca0.6Na0.3[Al11.1Si24.9O72] · 25.8H2O were studied by Xray diffraction analysis and 1H NMR spectroscopy. The arrangement of the extraframework subsystem was shown to be largely determined by hydrogen bonds N—H...O(H2O) of length 2.7–2.9 . The diffusive mobility of the ions was found to correspond to abnormally low energy barriers, similar to those for H2O diffusion. The activation parameters for the diffusion jumps of the ions and molecules are E(NH4) = E(H2O) = 31(2) kJ/mole, 0(NH4) = 2 · 1011 sec-1, 0(H2O) = 4 · 1012 sec-1 in NH4chabazite and E(NH4) = E(H2O) = 25(1) kJ/mole, 0(NH4) = 2 · 1010 sec-1, 0(H2O) = 3 · 1011 sec-1 in NH4clinoptilolite. It is suggested that the development of ion and molecular diffusion is caused by the same defects, whose formation with temperature rise is controlled by Hbond rearrangement. 相似文献
4.
Franz Pertlik 《Monatshefte für Chemie / Chemical Monthly》1987,118(12):1349-1355
1-(2-hydroxybenzoyl)piperidine, C12H15NO2, orthorhombic, Pbc21-C
2v
5
;a=9.529 (1),b=10.001 (1),c=11.652 (1) Å;Z=4. The structure was determined from 1 510 single crystal X-ray data by direct methods and the refinement of the structure parameters yieldedR=0.040. There is one molecule in the asymmetric unit.4-(2-hydroxybenzoyl)morpholine, C11H13NO3, orthorhombic, P212121-D
2
4
;a=13.006 (1),b=17.258 (2),c=9.125 (1) Å;Z=8. The structure parameters of the isotypic compound 4-(2-hydroxythiobenzoyl)morpholine were used in a starting set of refinement; finallyR=0.054 was obtained for 1 900 single crystal X-ray data. There are two molecules in the asymmetric unit.In both compounds the hydrogen atoms could be located by means of differenceFourier summations. The intermolecular hydrogen bonds with O ... O distances of 2.649 (2) Å for the piperidine derivate and 2.688 (3) resp. 2.754 (3) Å for the morpholine derivate are typical for intermediate bond strengths.
Die Strukturen von 1-(2-hydroxybenzoyl)piperidin und 4-(2-hydroxybenzoyl)morpholin
Zusammenfassung 1-(2-hydroxybenzoyl)piperidin, C12H15NO2, orthorhombisch, Pbc21-C 2v 5 ;a=9.529 (1),b=10.001 (1),c=11.652 (1) Å;Z=4. Die Struktur wurde aus 1 510 Einkristallröntgendaten mittels direkter Methoden bestimmt; die Strukturverfeinerung ergabR=0.040. Es ist ein Molekül in der asymmetrischen Einheit.4-(2-hydroxybenzoyl)morpholin, C11H13NO3, orthorhombisch, P212121-D 2 4 ;a=13.006 (1),b=17.258 (2),c=9.125 (1) Å;Z=8. Die Strukturparameter der isotypen Verbindung 4-(2-hydroxythiobenzoyl)morpholin wurden als Startsatz für die Strukturverfeinerung benutzt. Es wurdeR=0.054 aus 1 900 Einkristallröntgendaten erreicht. Es befinden sich zwei Moleküle in der asymmetrischen Einheit.In beiden Verbindungen konnten mittels Differenz-Fourier-Summierungen die Wasserstoffatome lokalisiert werden. Die intermolekularen Wasserstoffbrükken mit O ... O-Distanzen von 2.649 (2) Å für das Piperidinderivat und 2.688 (3) bzw. 2.754 (3) Å für das Morpholinderivat sind typisch für mittlere Bindungsstärken.相似文献
5.
A new ligand incorporating a dioxime moiety, (2E,3E)-3-[(2-{[(1E,2E)-2-(hydroxyimino)-1-methylpropylidene]amino}phenyl)imino]butan-2-one oxime, (H2Phmdo) (3) has been prepared by reacting 2,3-butanedionemono-{O-[4-(1-methyl-2-oxo-propylideneaminooxy)-2,3-bis-(1-methyl-2-oxo-propylideneaminooxy-methyl)-but-2-enyl]-oxime} (2) with 1,2-phenylenediamine. Mono-, di- and trinuclear copper(II) and/or nickel(II) complexes of H2Phmdo were characterized by elemental analyses, magnetic moments, 1H-n.m.r. and 13C-n.m.r., i.r. and mass spectral studies. The mononuclear copper(II) and nickel(II) complexes of H2Phmdo were found to have a 1:1 metal:ligand ratio. Elemental analyses, stoichiometric and spectroscopic data of the metal
complexes indicated that the metal ions are coordinated to the oxime and imine nitrogen atoms (C=N). In the dinuclear complexes,
in which the first Cu(II) or Ni(II) ion was complexed with nitrogen atoms of the oxime and imine groups, the second Cu(II) ion is ligated with dianionic oxygen atoms of the oxime groups and are linked to the 1,10-phenanthroline nitrogen atoms.
The data support the proposed structure of H2Phmdo and its complexes. 相似文献
6.
Serbest Kerim Karaböcek Serdar Değirmencioğlu İsmail Güner Saadettin Kormali Fatma 《Transition Metal Chemistry》2001,26(4-5):375-379
A new ligand incorporating a dioxime moiety, 3-{2-[2-(2-hydroxyimino-1-methylpropylideneamino)ethylamino]ethylimino}butan-2-one oxime, (H2mdo), has been synthesized and its mono-, di- and trinuclear copper(II), and hetero-dinuclear copper(II)–manganese(II) complexes have been prepared and characterized by elemental analyses, magnetic moments, 1H- and 13C-n.m.r., i.r. and mass spectral studies. A mononuclear copper(II) complex of H2mdo was found to have a 1:1 metal:ligand ratio. Elemental analyses, stoichiometric and spectroscopic data of the metal complexes indicated that the metal ions are coordinated to the oxime and imine nitrogen atoms (C=N); the data support the proposed structure of H2mdo and its complexes. 相似文献
7.
A new dioxime ligand, (2E,3E)-3-[(6-{[(1E,2E)-2-(hydroxyimino)-1-methylpropylidene]amino}-pyridin-2-yl)imino]butan-2-one oxime, (H2Pymdo) (3) has been synthesized in H2O by reacting 2,3-butenedione monoxime (2) with 2,6-diaminopyridine. Mono-, di- and tri-nuclear copper(II) complexes of the dioxime ligand (H2Pymdo) and/or 1,10-phenanthroline have been prepared. The dioxime ligand (H2Pymdo) and its copper(II) complexes were characterized by 1H-n.m.r., 13C-n.m.r. and elemental analyses, magnetic moments, i.r. and mass spectral studies. The mononuclear copper(II) complex of H2Pymdo was found to have a 1:1 metal:ligand ratio. Elemental analyses, stoichiometric and spectroscopic data of the metal complexes
indicated that the metal ions are coordinated to the oxime and imine nitrogen atoms (C=N). In the dinuclear complexes, in
which the first Cu(II) ion was complexed with nitrogen atoms of the oxime and imine groups, the second Cu(II) ion is ligated
with dianionic oxygen atoms of the oxime groups and are linked to the 1,10-phenanthroline nitrogen atoms. The trinuclear copper(II)
complex (6) was formed by coordination of the third Cu(II) ion with dianionic oxygen atoms of each of two molecules of the mononuclear
copper(II) complexes. The data support the proposed structure of H2Pymdo and its Cu(II) complexes. 相似文献
8.
Hiroyuki Ito Toru Sakurai Takekiyo Matsuo Toshio Ichihara Itsuo Katakuse 《Zeitschrift für Physik D Atoms, Molecules and Clusters》1997,40(1):102-104
Mass spectra of doubly charged mercury clusters (m/z=30-1065) were investigated by secondary ion mass spectrometry. Positively charged ions were generated from an amalgam of mercury and silver by bombardment with a xenon ion beam and mass analysis by a grand-scale sector type mass spectrometer. Hg n 2+, n=1-10 and Hg n +, n =1- 5 were observed. Some doubly charged mercury clusters, (Hg n 2+) survived at least for 0.1 ms. 相似文献
9.
M. Judith Percino Víctor M. Chapela Omar Urzúa Ling-Fa Montiel Cecilia Rodríguez-Barbarín 《Research on Chemical Intermediates》2007,33(7):623-629
The novel intermediate 1-(p-fluorophenyl)-2-(2′-pyridyl)ethanol or 2-[2′-(1-hydroxy-1-(p-fluorophenyl)ethyl]pyridine and the corresponding novel dehydration compound 1-(p-fluorophenyl)-2-(2′-pyridyl)ethene or 2-[p-fluorophenylvinyl]pyridine were obtained from the condensation reaction of p-fluorophenylaldehyde and 2-picoline under catalyst-and solvent-free conditions. The intermediate 1-(p-fluorophenyl)-2-(2′-pyridyl)ethanol was obtained at 42 h reaction time and temperature of 120°C, respectively. 1H-NMR, IR spectroscopic data of the 1-(p-fluorophenyl)-2-(2-pyridyl)ethanol clearly showed the presence of the-CH2-CHOH-group. The compound was obtained as a white powder with m.p. 121–122°C and a yield of 8%. For 1-(p-fluorophenyl)-2-(2-pyridyl)ethene, the reaction conditions were similar, but the reaction temperature was increased to yield
the double bond in the 1-(p-fluorophenyl)-2-(2′-pyridyl)ethene. At the reaction temperature of 140°C, the compound was a slightly brown powder with a
m.p. of 78°C and yield of 18%. 1H-NMR, IR spectroscopic data for the 1-(p-fluorophenyl)-2-(2′-pyridyl)ethene showed the presence of a double bond in trans configuration (-CH=CH-), characteristic of a styrylpyridine. 相似文献
10.
(Extraction of alkali on alkaline earth metal ions with (sym-dibenzo-14-crown-4-oxy)- and (sym-dibenzo-16-crown-5-oxy)-carboxylic acids.)The extraction of lithium, sodium, potassium, calcium and some other metal ions with dibenzo-4-crown-4-oxy- and dibenzo-16-crown-5-oxycarboxylic acids containing the groups -CH2COOH, -(CH2)2COOH, -(CH2)3COOH, -CH(C2H5)COOH and -CH(C4H9)COOH was studied. The extraction increases as a function of the lipophilic character of the carboxylic acid group. Calcium, barium and strontium ions are better extracted than Li+, Na+ and K+; there are only small differences among the alkaline earth metal ions. Evaluated from the extraction data, the composition of the extracted species was 1:1 (metal/ligand) for Li+, and 1:2 for CaCa2+; Na+ and K+ favour the formation of 1:2 complexes with dibenzo-14-crown-4-derivatives bbut 1:1 complexes with dibenzo-16-crown-5-oxy-carboxylic acids. The dependence of the distribution ratio on pH does not provide unequivocal evidence for the composition of the extracted compounds. 相似文献
11.
The reagent 5,6-diphenyl-2,3-dihydro(asym)triazine-3-thione produces a green complex with perrhenate in hydrochloric acid medium in presence of stannous chloride. The complex on extraction in chloroform shows a peak at 685 nm. The system obeys Beer's law from 2–10 p.p.m. of rhenium and its molar absorptivity is 1.53-l0-4. It tolerates the presence of a large number of ions, including MoXXX and WXXX. Job's and molar ratio methods suggest that rhenium and the reagent are present in the ratio 1:2 and the isolated complex is of the same composition, i.e. ReO(C25H10N3S)2. 相似文献
12.
《Analytical letters》2012,45(7):471-477
Abstract An indirect method for the determination of OsO4, in the p.p.m. region is possible by measuring the decrease in fluorescence of the 4,6-bismethylthio-5-aminopyrimidine when OsO4, is added. At liquid N2 temperatures 10 p.p.b. OsO4, can be detected. The OsO4, to ligand ratio was found to be 2:3. For 1 p.p.m. OsO4, 10 p.p.m. Ir+3, 1 p.p.m. Fe+3 and less than 1 p.p.m. Ru+3 and Pd+2 can be tolerated. The fluorescent system is not affected by pH in the 3–12 ranges. It is suggested that the decrease in fluorescence results from a complexation reaction with the first site of reaction being the NH2. group. With increasing OsO4, concentration, oxidation appears to occur which produces a black product. This oxidation was not observed at p.p.b. concentrations of Os. 相似文献
13.
L. V. Klyba N. A. Nedolya O. A. Tarasova E. R. Zhanchipova O. G. Volostnykh 《Russian Journal of Organic Chemistry》2010,46(2):218-225
Mass spectra were investigated for the first time of four structural isomers of heterocycles, formerly inavailable 7-methyl-2-(methylsulfanyl)-3-(1-ethoxyethoxy)-4,5-dihydro-3H-azepine, 2,2-dimethyl-6-(methylsulfanyl)-5-(1-ethoxyethoxy)-2,3-dihydropyridine, 1-isopropyl-2-(methylsulfanyl)-3-(1-ethoxyethoxy)pyrrole,
and N-isopropyl-N-methyl-3-(1-ethoxyethoxy)-2-thiophenamine prepared from a single linear precursor, adduct of α-lithiated 1-(1-ethoxyethoxy)allene
and isopropyl isothiocyanate. All compounds formed a molecular ion (I
rel
1–6%) whose primary fragmentation at the electron impact (70 eV) occurs in two principal directions related to the cleavage
of the C-O bonds in the 1-ethoxyethoxy-substituent: with a simple rupture of the bonds C-OEt and C-O(heterocycle) and with
the elimination of an ethoxyethene molecule. In the spectra of 4,5-dihydro-3H-azepine and 2,3-dihydropyridine the first fragmentation
channel of [M]+· dominates. The second direction prevailes at the fragmentation of pyrrole and thiophene molecular ions leading to an odd-electrons
ion with m/z 171. Further fragmentation of this ion is characteristic of each isomer and resulted in the formation of diagnostic
ions providing a possibility of identification of these isomers by mass spectrometry. 相似文献
14.
4-(2-Pyridylazo)resorcinol (PAR) forms 2 red chelates with scandium in aqueous solution at pH ? 2 or 5: SCRH2+ and ScR2-. The former can be used to determine 0.05–2.4 μg Sc/ml at pH 3.5–4.5 with μ = 0.4; measurement is done at 530 mμ. Many ions interfere and separation is necessary. 相似文献
15.
Preparation and Characterization of Chromium of Chromium(V)- and Manganese(V)- nitridophthalocyanines(1-) and -(2-): [MNPc(1-)]+ and [MNPc(2-)] (M=Cr, Mn) Nitridophthalocyaninatochromium(V), [CrNPc(2-)], is prepared by oxidation of [Cr(OH)2PC(2-)] with chlorine in the presence of excess ammonia as a paramagnetic (μeff = 1,99 B.M.), Microcrystalline blue powder. Through chemically very stable it reacts as well as the isostructural nitridophthalocyaninatomanganese(V) with bromine or concentrated nitric acid giving ring- oxidized darkblue nitridophthalocyaninatomental(poly)bromides or -nitrates, [MNPc(1-)]X (M=Cr, Mn; X=Bry, NO3; y≈?2). The nitrido-metal stretching vibration (ν(N?M)) is independent of the oxidation state of the Pc-ligands at ca. 1017 cm?1 for the chromium and at ca. 1055 cm?1 for the manganesenitridophthalocyanines. ν(N?Mn) is resonance Raman (r.r.) enhanced, ν(N?Cr) not. The characteristic differences in the u.v. -vis., f.i.r./m.i.r. and r.r. spectra of [MNPc(2-)] and [MNPc(1-)+ and the influence of aggregation of phthalocyanine-radicals are discussed. 相似文献
16.
The synthesis, characteristics and analytical reactions of 1-(1,2,4-triazoly 1-3-azo)-2-naphthol are described. Coloured complexes are formed with 21 metal ions. For the cadmiuin(II) complex, the molar absorptivity is 2.8 × 104 1 mol-1 cm-1 at 515 nm for 40% () ethanolic solutions at pH 8.0. For the mercury(II) complex at pH 10, the molar absorptivity is 2.7 × 104 mol-1 cm-1 at 530 nm. Complexes of the ML2 type are formed. 相似文献
17.
Muhammad Mufazzal Saeed 《Journal of Radioanalytical and Nuclear Chemistry》2006,267(2):427-433
Summary The sorption of microquantities of Tm(III) ions on washed polyurethane foam (PUF) from a mixture of aqueous solution and ethanol
containing PAN was examined. The maximum sorption of 3.18. 10-6M solution of Tm(III) ions was observed at pH 8 with 30-minute equilibration time. The optimum ratio of aqueous-ethanol phase
for the sorption of Tm(III) ions was found to be 3:1 v/v, respectively. The sorption rate of metal ions on PUF is followed a first order kinetics and obeyed the equation for an intra
particle diffusion process. The equilibrium concentration data of Tm(III) ions could be described satisfactorily by several
adsorption isotherms. The Freundlich adsorption isotherm constants 1/nand KFare 0.66±0.02 and (5.7±0.3). 10-3mol. g-1, respectively. The Langmuir isotherm constants for monolayer coverage (Q) and binding strength of sorption (b) are (2.5±0.7). 10-5mol. g-1and (1.6±0.1). 104l. mol-1, respectively. The sorption capacity derived from Dubinin-Radushkevich (D-R) isotherm is (1.7±0.2). 10-4mol. g-1and the sorption free energy (E) is 9.8±0.2 kJ. mol-1indicating chemisorption phenomena. The thermodynamic parameters indicate that the sorption of Tm(III) ions onto PUF is endothermic,
entropy driven and spontaneous in nature. 相似文献
18.
In this article a new coated platinum Cu2+ ion selective electrode based on 2-((2-(2-(2-(2-hydroxy-5-methoxybenzylideneamino)phenyl)disufanyl)phenylimino) methyl)-4-methoxyphenol Schiff base (L1) as a new ionophore is described. This sensor has a wide linear range of concentration (1.2 × 10−7-1.0 × 10−1 mol L−1) and a low detection limit of 9.8 × 10−8 mol L−1of Cu(NO3)2. It has a Nernstian response with slope of 29.54 ± 1.62 mV decade−1 and it is applicable in the pH range of 4.0-6.0 without any divergence in potentioal. The coated electrode has a short response time of approximately 9 s and is stable at least for 3.5 months. The electrode shows a good selectivity for Cu2+ ion toward a wide variety of metal ions. The proposed sensor was successfully applied for the determination of Cu2+ ion in different real and environmental samples and as indicator electrode for potentiometric titration of Cu2+ ion with EDTA. 相似文献
19.
D. Carbone S. Fisichella S. Occhipinti G. Scarlata 《Journal of heterocyclic chemistry》1982,19(6):1505-1509
The mass spectra of some (Z)α-(4-R′-phenyl)-β-(2-thienyl-5-R)acrylonitriles (R = H, CH3, Br; R′ = H, CH3O, CH3, Cl, NO2) at 70 eV are reported. Mass spectra exhibit pronounced molecular ions. The compound's where R = H, and CH3 are characterized by the occurrence of a strong [M - H]+ peak. Moreover, in all the compounds a m/z 177 peak occurs. In the compounds where R = H, [M - HS]* and [M - CHS]* ions are present except the nitroderivatives. Where R = CH3, [M - HS]+ ion occurs. 相似文献
20.
Bei Yan Guang-ji Wang Jian-guo Sun Fen-zhi Sun Xiao-yu Li Xiao-ming Wu Jin-yi Xu Yuan-ting Zheng Hua Lv 《Chromatographia》2007,66(1-2):55-61
A simple and sensitive reversed-phase LC-ESI-MS method to identify and quantitate 5-n-butyl-4-{4-[2-(1H-tetrazole-5-yl)-1H-pyrrol-1-yl]phenylmethyl}-2,4-dihydro-2-(2,6-dichloridephenyl)-3H-1,2,4-triazol-3-one (1b), a new Angiotensin II type 1 receptor antagonist in rat plasma has been developed and validated.
Sample preparation used a simple liquid–liquid extraction with ethyl acetate. Separation was achieved by gradient elution
on a C18 column. The mobile phase consisted of acetonitrile and water (0.05% triethylamine and 0.05% acetic acid) at a flow rate of
0.2 mL min−1. The detection utilized selected ion monitoring (SIM) in the negative mode at m/z 507.1 and m/z 407.2 for the deprotonated molecular ions of 1b and the internal standard irbesartan, respectively. The lower limit of quantification
was reproducible at 5 ng mL−1 with 100 μL of plasma and the good linear was observed in the 5–500 ng mL−1 range. This concentration range corresponded well with the plasma concentrations of 1b in pharmacokinetic studies. Recoveries
of 1b in rat plasma were 76.1, 74.6 and 79.0% at 5, 50 and 500 ng mL−1. The RSD of intra-assay and inter-assay variations were all less than 5%. This validated LC-ESI-MS assay is an economic,
quick, precise and reliable method for the analysis of 1b in pharmacokinetic studies. 相似文献