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1.
The formation of SiSi-bonds by a photochemical reaction of silylmercury compounds is described. The silylmercury compounds [(X
3Si)3Si]2Hg (X=Cl, OCH3) were synthesized via theVyazankin Hydrid method with (X
3Si)3SiH and Bis(t-butyl)mercury. By UV-irradiation of these products in hexane as a solvent, the oligosilanes [(X
3Si)3Si]2 are formed in good yields. All these compounds are charactericed by spectroscopical methods. 相似文献
2.
Akram M. El-Didamony 《Central European Journal of Chemistry》2005,3(3):520-536
Three simple, accurate, and sensitive spectrophotometric methods (A, B and C) have been described for the indirect assay of
diltiazem hydrochloride (DIL.HCl), either in pure form or in pharmaceutical formulations. The first method (A) is based on
the oxidation of DIL.HCl by N-bromosuccinimide (NBS) and determination of unconsumed NBS by measuring the decrease in absorbance
of amaranth dye (AM) at a suitable λ
max
=521 nm. Other methods (B) and (C) involve the addition of excess cerric ammonium sulfate (CAS) and subsequent determination
of the unconsumed oxidant by a decrease in the red color of chromotrope 2R (C2R) at a suitable λ
max
=528 nm or a decrease in the orange-pink color of rhodamine 6G (Rh6G) at λ
max
=525 nm, respectively. Regression analysis of Beer-Lambert plots showed good correlation in the concentration ranges 3.0–9.0,
3.5–7.0 and 3.5–6.3 μg ml−1 for methods A, B and C, respectively. The apparent molar absorptivity, Sandell's sensitivity, detection and quantification
limits were calculated. The proposed methods have been applied successfully for the analysis of the drug in its pure form
and its dosage form. No interference was observed from a common pharmaceutical adjuvant. Statistical comparison of the results
with the reference method shows excellent agreement and indicates no significant difference in accuracy and precision. 相似文献
3.
Lee Ju-No Lee Jin-Suk Shin Chul-Seung Park Soon-Chul Kim Seung-Wook 《Applied biochemistry and biotechnology》2000,84(1-9):329-342
Possible methods to minimize the toxic effects of SO
x
and NO
x
on the growth of a highly CO2 tolerant and fast-growing microalga, Chlorella sp. KR-1, were investigated. Maintaining the pH of the culturing media at an adequate value was quite important to enhancing
the tolerances of the microalgae to SO
x
and NO
x
. Controlling the pH by adding an alkaline solution, using a low flow rate of gas fed to the culture, and using a high concentration
of inoculating cells were effective methods to maintaining the proper pH of the culture. Controlling the pH was the most effective
method but could be applied only for some specific microalgae. 相似文献
4.
Robert Ott Erfried Pinter Peter Kajtna 《Monatshefte für Chemie / Chemical Monthly》1980,111(4):813-820
In acetic (aqueous or chloroform) solutionp-benzoquinones yield with primary aliphatic amines mainly 2-(N-alkyl-p-hydroxy-anilino)-1,4-benzoquinones besides the 2-alkylamino- and 2,5-bis(alkylamino)-quinones. The methyl-, ethyl-,n-propyl-,n-butylhomologues ofp-benzoquinone and the isomer methylderivatives of toluquinone are described. Their structure were established by spectroscopic (UV/VIS, IR, NMR) methods and by synthesis of the methylderivative3 a fromp-benzoquinone andp-hydroxy-N-methylaniline. The influence of other acids on the reaction was studied.
Herrn Prof. Dr.G. Zigeuner, Universität Graz, mit den besten Wünschen zum 60. Geburtstag gewidmet. 相似文献
5.
Axel-Rüdiger Schulze Hanskarl Müller-Buschbaum 《Monatshefte für Chemie / Chemical Monthly》1981,112(2):149-156
The hitherto unknown compound Ca3Ga4O9 was prepared and investigated by X-ray single crystal methods. Ca3Ga4O9 has orthorhombic symmetry:a=1435.8;b=1682.5;c=532.1 pm; space group C
2v
11
–Cmm2,Z=6. The tetrahedra network (circles of 4 and 5 GaO4-tetrahedra) and the surrounding of Ca2+ are described and discussed with respect to other oxogallates. 相似文献
6.
Heinz Falk Günther Höllbacher Otmar Hofer Norbert Müller 《Monatshefte für Chemie / Chemical Monthly》1981,112(3):391-403
A force field model was designed with respect to the special needs of bile pigments. It is parametrized and tested using partial structures of bile pigments as well as an integral pigment; the solution structures of the molecules were previously deduced using independent experimental methods.
38. Mitt::Falk, H., Schlederer, T., Wolshann, P., Mh. Chem.112, 199 (1981). 相似文献
7.
Victoria Sharratt Callum A.S. Hill Darwin P.R. Kint 《Polymer Degradation and Stability》2009,94(9):1589-1594
A detailed study of early colour change in Scots pine (Pinus sylvestris) due to accelerated simulated sunlight exposure was undertaken focusing on the first 24 h of change. Colour changes were monitored with a Datacolor check spectrophotometer and compared with a set of controls. Measurements on both samples and controls were performed hourly for the first 24 h and there after daily until 168 h’ exposure with extra measurements at 200, 350 and 500 h. A subset of samples was extracted prior to exposure to check the effects of any colour change due to the presence of extractives. Data was analysed using the reflectance spectra (400–700 nm) as well as the CIE-L*a*b* system and ΔE. The majority of colour changes were found to occur within the first 24 h. This was unaffected by the removal of extractives from the wood and was independent of temperature. Mechanical properties and weight changes were also monitored to allow a comparison of sensitivity between the differing methods. 相似文献
8.
Harald Lehner Helmut Paulus Karl Schlögl 《Monatshefte für Chemie / Chemical Monthly》1981,112(4):511-516
The absolute configuration of (+)-12-bromo-[2.2]metacyclophane-4-carbonitril [(+)-4 e] was determined by theBijvoet X-ray diffraction method as(R)
p (Fig. 1). This result allows the unambigous assignment of the absolute chiralities of all optically active 4-monosubstituted, 4,14-homodisubstituted, 4,12- and 4,14-heterodisubstituted [2.2]metacyclophanes chemically correlated with (+)-4 e. The result is compared with those obtained by other methods for establishing the absolute configuration.Stereochemistry of Planar Chiral Compounds, Part 8. Part 7:Krieger, Ch., Lehner, H., Schlögl, K., Mh. Chem.107, 195 (1976). 相似文献
9.
Dmitrenok A. S. Radhika P. Anjaneyulu V. Subrahmanyam C. Subba Rao P. V. Dmitrenok P. S. Boguslavsky V. M. 《Russian Chemical Bulletin》2003,52(8):1868-1872
Sphingolipids and glycolipids including previously unknown (2S,3S,4R)-1,3,4-trihydroxy-2-(2-(R)-hydroxyoctadecanoylamino)octadec-8E-ene, (2S,3R)-1,3-dihydroxy-2-octadecanoylamino-4E,8E-hexadecadiene, and (2-hydroxy-3-hexadecyloxypropyl)--L-fucopyranoside were isolated from soft corals collected on the shelf near the Andaman Islands (Indian Ocean). The structures of all compounds were established by spectroscopic methods and chemical analyses. The lipids possessed antibacterial activity against Bacillus subtilis, Bacillus pumilus, Escherichia coli, and Pseudomonas aeruginosa and antifungal activity against Aspergillus niger, Rhizopus oryzae, and Candida albicans. 相似文献
10.
Richard Vytlacil 《Monatshefte für Chemie / Chemical Monthly》1980,111(5):1075-1086
In the ternary system silver chloride-lithium chloride-sodium chloride the kinetics of the galvanic deposition of silver on graphite electrodes was investigated as well as its dissolution without current in the molten salt saturated with chlorine gas.In addition the emf-values were measured in the temperature range between 923 K and 1,173 K by means of, the formation cell graphite/Ag(s)/AgCl(l)–LiCl(l)–NaCl(l)/Cl2 graphite From these data the partial molar free excessGibbs energies were calculated. Using the equation for a multicomponent system as suggested byRedlich-Kister
1
G
AgCl
E
values were obtained by a non-linear fitting process, where the fit was performed for all investigated temperatures and over the entire concentration range in the ternary system. With the parameters obtained the partial and integral excess valuesG
i
E
,G
E
,H
i
E
,H
E
,S
i
E
andS
E
were calculated. 相似文献
11.
Gubskaya V. P. Konovalova N. P. Nuretdinov I. A. Fazleeva G. M. Berezhnaya L. Sh. Sibgatullina F. G. Karaseva I. P. 《Russian Chemical Bulletin》2002,51(9):1723-1726
New fullerenopyrrolidines were synthesized by the three-component reactions of fullerene C60, N-methylglycine, and aromatic aldehydes, viz., N,N-bis(2-chloroethyl)-4-aminobenzaldehyde, N-(2-chloroethyl)-N-methyl-4-aminobenzaldehyde, indole-3-carbaldehyde, 4-phenylbenzaldehyde, and anthracene-9-carbaldehyde. The structures of the resulting compounds were established by spectroscopic methods. 相似文献
12.
麝香草的新单萜配糖物的分离与合成 总被引:1,自引:0,他引:1
从麝香草(Thymus vulgaris L)的甲醇萃取物中分离出三个单萜配糖物. 用核磁共振光谱确定了它们的结构为对伞花-9-基-β-D-葡糖苷(1), 5-β-D-葡糖苷百里氢醌(2)和2-β-D-葡糖苷百里氢醌(3). 其中1是新化合物, 用以对伞花-9-醇为原料的对映体选择性合成方法确定了化合物1的8位的立体化学为R型. 相似文献
13.
The derivatives of cyano complex compounds of iron, cobalt and manganese with the triphenylphosphonium-cation were prepared and investigated by IR- andMössbauer-spectroscopic methods. The thermal decomposition of the triphenylphosphonium-cyanometallates leads to intermediates which can be isolated.
Als 6. Mitt. gilt:S. Papp undM. Pál, Magy. Kém. Folyóirat83, 346 (1977). 相似文献
14.
Erich Zobetz 《Monatshefte für Chemie / Chemical Monthly》1980,111(6):1253-1263
KAg(NO3)2 crystallizes in space group P21/a-C
2h
5
,a=13.953,b=4.955,c=8.220 Å, =97.76°,Z=4. X-ray intensities were collected with a two-circle diffractometer. The structure was solved by means of direct methods andFourier syntheses and was refined by the least squares method toR=0.034 with 1346 observed reflexions.
1
{Ag2(NO3)4}2–-chains run parallel toy and are linked by potassium ions. Ag shows a distorted tetrahedral coordination with four relatively close O. K is irregularily surrounded by ten O. The isotypic compounds NH4Ag(NO3)2 and RbAg(NO3)2 were refined toR=0.032 and 0.035, respectively. The coordination figures are compareable with those in KAg(NO3)2. 相似文献
15.
16.
Charge-density calculations have been made on six aromatic molecules by making use ofHückel MOLCAO andDel Re methods and correlated with experimental activation energy values to test certain earlier interpretations given.
Korrelation von Ladungsdichte und Aktivierungsenergie für elektrophile aromatische Substitutionsreaktionen
Zusammenfassung Für sechs aromatische Moleküle wurden mittelsHückelrechnung (MO-LCAO) und nach der Methode vonDel Re die Ladungsdichten errechnet und diese mit experimentellen Aktivierungsenergien korreliert.相似文献
17.
Capillary electrophoresis approaches have been utilized for the study of bacteria under specific experimental conditions.
The main objective within our research work was to study electrophoretic behaviors of Pseudomonas aeruginosa by means of capillary electrophoresis with UV and fluorescence detection. Edwardsiella tarda and Enteropathogenic escherichia coli were also included in the study. The results showed that proper pretreatment (vortexing or sonication) for each bacterial
sample before injection was necessary to disperse the clusters of cells, which is helpful to observe the single peaks and
better peak shape of bacteria during electrophoresis. Apart from this, it was found that ionic strength of buffer affected
mobilities of Pseudomonas aeruginosa as a result of increasing of buffer concentration from 25 mM to 150 mM. Moreover, sharp and single peaks were still observed
without significant increase of noise in the concentration range. Eventually, mixtures of bacteria were well separated under
optimized separation conditions with UV and fluorescence detection. In the mean time, comparison of concentration sensitivities
for Pseudomonas aeruginosa by UV and fluorescence detection was made. Blue light emitting diode induced fluorescence detection was found to be more
sensitive (8.5-fold higher) than UV detection with home-made fluorescence detection system. Generally, proposed CE methods for the analysis of bacteria could be potentially valuable for the monitoring of bacteria contamination in real life. 相似文献
18.
Hansjörg Meyer Hanskarl Müller-Buschbaum 《Monatshefte für Chemie / Chemical Monthly》1981,112(1):51-57
Solid state reaction of CuO and Al2O3 with a flux of PbO about 930°C and reaction time of 8d gives the new compound Cu2Al4O7. The red single crystals were examined by energydispersive microanalysis and X-ray diffraction methods. Cu2Al4O7 has cubic symmetry, space group
,a=908.0 pm. The typical coordination of Cu+ (CN=6 and CN=12) and the interstitial arrangement of the AlO4-tetrahedra are discussed with respect to related compounds. 相似文献
19.
The nuclear magnetic resonance spectra of the systems isopropanol/n-hexane and isopropanol/n-heptane are recorded to deduce thermodynamic functions. A discussion ofSaroléa-Mathot's methods follows.Für die im Titel genannten Systeme werden aus den NMR-Spektren thermodynamische Funktionen abgeleitet. Eine Diskussion derSaroléa-Mathot-Methode wird präsentiert.
Zur Thermodynamik des Isopropanol/n-Hexan und Isopropanol/n-Heptan Systems, II. NMR-Untersuchungen相似文献
20.
B离子掺杂TiO2催化剂(TiO2-xBx)光催化活性的研究 总被引:3,自引:0,他引:3
采用溶胶-凝胶法制备出纳米TiO2和TiO2-xBx催化剂. 光催化实验证明, TiO2-xBx催化剂的紫外、可见光催化活性均高于TiO2. XRD, XPS和Raman结果表明, B离子是以取代式掺杂占据了TiO2的O2-的晶格位置. UV-Vis和PL谱的结果表明, B离子的2p轨道与O的2p轨道形成混合价带, 产生可见光响应, B离子的掺入有效地阻止了光生载流子的复合, 促进了其分离, 是TiO2-xBx催化剂紫外、可见光催化活性提高的主要原因. 相似文献