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991.
The surface enhanced Raman spectrum of benzotriazole (BTAH) adsorbed on a copper electrode has been studied as a function of the potential applied to the electrode. The effect of pH and of the type of halide in the electrolyte solution has also been investigated. The presence of some complexes involving Cu(I), benzotriazole or benzotriazolate (BTA-) and the halide has been characterized. The protective film formed on copper surface, in the presence of benzotriazole, has been identified as cuprous benzotriazolate [Cu(I)BTA]. 相似文献
992.
Methods for the investigation of pore and molecular structure of synthetic membranes are reviewed. Membranes are classified as coarse-porous, fine-porous, and solution-diffusion membranes, on one hand; and homogeneous, asymmetric, and composite on the other, Pore structure of synthetic membranes can be elucidated in detail only by electron and raster electron microscopic investigations. Inspection of molecular structure requires diversely specific test probes such as low-energy neutron scattering and/or diffraction, and gas sorption and permeability measurements, as well as thermodynamic and thermomechanical analysis. Other methods used to elucidate pore and molecular structure of synthetic membranes are discussed and, concurrently, membrane structure is correlated with membrane permeability. 相似文献
993.
W. Gombler 《无机化学与普通化学杂志》1978,439(1):193-206
The Sulfenic Fluorides CF3SF and CF2CISF and their Dimers The reactions of RfSCl (Rf = CF3, CF2Cl) with HgF2 and AgF give RfSF and the dimer product RfSF2SRf in high yield and various ratios, in contrast, activated KF leads only to RfSF in low yield. A complex of transition metal and sulfenic halide as an intermediate step is discussed for the dimerisation. As liquid CF3SF2SCF3 disproportionates into CF3SF3 and CF3SSCF3 and the hydrolysis of CF3SF2SCF3 gives the stable compound CF3S(O)SCF3 · PF3 reacts with RfSF as well as with RfSF2SRf to RfSPF4. The products of the spontaneous decomposition of CF2ClSF were investigated. I.r., n.m.r., and mass spectra are reported and discussed. It was possible to carry out vapour pressure measurements of CF2ClSF. 相似文献
994.
Stoffwechselprodukte von Mikroorganismen 6-Chlorgenistein und 6,3′-Dichlorgenistein. 164. Mitteilung
Metabolites from Microorganisms, 6-Chlorogenistein and 6,3′-Dichlorogenistein A strain of Streptomyces griseus produced chlorinated metabolites in media containing soybean meal. Two of these metabolites were isolated together with a chlorine free compound which could be identified as the isoflavone genistein (I) by its spectral properties and by comparison with an authentic sample. By NMR. and mass spectroscopy the chlorinated compounds were shown to be 6-chlorogenistein (II) and 6,3′-dichlorogenistein (III). The 7-glucoside of genistein is a constituent of soybean meal; it is hydrolysed and chlorinated by Streptomyces griseus. 相似文献
995.
The naphthalene absorption in the spectral region of 3500–4100 Å consists of two perpendicularly polarized band systems. This can be shown by polarization measurements. The arguments given do not allow a decision as to whether or not the short axis polarized band is the 3Ag− ← 3Biu+ transition or an induced vibronic band of the 3B3g− ← 3Biu+ transition generated by a b3g vibration mode. The T-T polarization of phenanthrene as a function of the excitation wavenumber is quantitatively compared with the equivalent S1 ← S0 fluorescence polarization. There is a good agreement between the calculated and the measured curve. 相似文献
996.
Zusammenfassung Ein Gemisch von-Naphthylisocyanat mit etwa 6 1,4-Diazabicyklo-[2,2,2]-oktan (10–15 ml) reagiert quantitativ und sofort mit mg-Mengen Wasser unter Bildung von Kohlendioxid, das anschließend automatisch titriert wird. Wassermengen von etwa 0,3–3 mg lassen sich in etwa 8 min mit einer Standardabweichung von 0,8% rel. bestimmen.
The automatic determination of carbon and hydrogen. IV
Summary A mixture of about 10–15 ml of-naphthylisocyanate with about 6%. 1,4-diazabicyclo [2,2,2]-octane reacts instantaneously and quantitatively with water in mg quantities. The resulting carbon dioxide is automatically titrated. Amounts of water of about 0.3–3 mg were determined within 8 min. with a standard deviation of 0.8% rel.相似文献
997.
Zusammenfassung Einige Änderungen an der Apparatur zur Stickstoffschnellbestimmung nachMerz wurden vorgenommen. Dadurch wird erreicht, daß zwischen den einzelnen Verbrennungen Sauerstoff das Verbrennungsrohr durchspült und vor dem Reduktionsrohr nach außen tritt. Der Verbrennungsraum ist daher bereits zu Beginn jeder Analyse mit Sauerstoff gefüllt, wodurch günstigere Bedingungen für die schlagartige Verbrennung erzielt werden. Der Umbau der von der Firma Heraeus gelieferten Apparatur und die Herstellung eines Oxydationskatalysators (Kobaltoxid-Wolframoxid) werden beschrieben.
Contribution to the rapid nitrogen determination according to merz
Summary The apparatus for rapid nitrogen determination according toMerz has been modified. Between each two combustions, oxygen is flushed through the combustion tube and is vented before the reduction tube. Therefore, at the beginning of each analysis, the combustion chamber is filled with oxygen, providing a more favorable atmosphere for the rapid ignition. The alterations in the Hereaus apparatus and the preparation of an oxidation catalyst (cobalt oxide and tungsten oxide) are described.相似文献
998.
A series of phenylated dihydrophthalimides has been synthesized by the Diels-Alder reaction of tetraphenylcyclopentadienone with maleimide, N-phenylmaleimide, and N,N'-o-, -m-, and -p-phenylenedimaleimide. Subsequent dehydrogenation of these compounds yielded the corresponding phenylated phthalimides. These phthalimides were also obtained in one step when the initial reactions were carried out in refluxing nitrobenzene. 相似文献
999.
Spectra of fluorobenzene (FB), pentafluorobenzene (PFB) and hexafluorobenzene (HFB) from 50000 to 93000 cm−1 are presented. Rydberg series converging to the first and to a higher ionization limit are found in each molecule. The orbital natures of the excited states and ions are discussed. 相似文献
1000.
Zusammenfassung Es werden die Eigenschaften und Reaktionen von 1,3-Dichloruretidindion, einem neuen Dimeren des Chlorisocyanats, beschrieben. Durch thermische Isomerisierung entsteht der bereits bekannte N,N-Dichlor-N-carbonylharnstoff. Die IR-Spektren beider Verbindungen werden mitgeteilt.
Mit 2 Abbildungen 相似文献
Chemistry of chloro-isocyanate, III: 1,3-Dichlorouretidinedione, a new chloroisocyanate dimer
The properties and reactions of 1,3-dichloro-uretidinedione, a new dimer of chloro-isocyanate, are described. Its thermic isomerization gives the known N,N-dichloro-N-carbonyl-urea. The IR-spectra of both compounds are published.
Mit 2 Abbildungen 相似文献