ISSN:0021-2148    

DOI:10.1002/ijch.197100101

出版商:WILEY‐VCH Verlag    

年代:1971

数据来源: WILEY

摘要:

AbstractThe chemical technology of the future will require a deeper knowledge of fundamental molecular‐dynamical processes. It will no longer suffice to be able to systematize (and even calculate) static properties of simple molecules in equilibrium or to produce tables of Arrhenius kinetic parameters characterizing the rate constants of a host of elementary chemical reactions. In order to make significant gains, in the sense of “breakthrough technology”, an intimate knowledge of basic molecular dynamical behavior will be needed. Such insight is derivable from a new class of experiments at the atomic and molecular level and from new theoretical‐computational approaches to molecular‐dynamical problems. To illustrate these new requirements, and the potential practical applications of an improved understanding at the basic level, examples are presented in the areas of combustion and atmospheric pollution, atmospheric and ionospheric chemistry, synthetic applications of selective excitation, lasers in chemistry and chemical‐to‐radiation ener

ISSN:0021-2148    

DOI:10.1002/ijch.197100088

出版商:WILEY‐VCH Verlag    

年代:1971

数据来源: WILEY

摘要:

AbstractThe triplet absorption spectrum of tryptophan in ethylene‐glycol/water glass at 77°K has been registered. It is demonstrated that light of wavelength 250 nm produces trapped electrons by a two‐photon process in this system. In both UV‐ and X‐ray‐induced ionization the probability that an ejected electron will recombine with its mother ion is around 0.5. Bleaching with visible light causes the trapped electrons to react with the solvent and there is also a considerable degree of retrapping. The retrapping becomes more probable when the temperature

ISSN:0021-2148    

DOI:10.1002/ijch.197100089

出版商:WILEY‐VCH Verlag    

年代:1971

数据来源: WILEY

摘要:

AbstractExperiments indicated that adsorptive forces lower the potential energy of water inside uncharged cellulose acetate membranes. As a result it is postulated that the steady‐state pressure distribution during osmosis is affected. In particular, a sudden rise in pressure should occur across the water‐membrane interface. Thus, in this region, water may flow against a pressure gradi

ISSN:0021-2148    

DOI:10.1002/ijch.197100090

出版商:WILEY‐VCH Verlag    

年代:1971

数据来源: WILEY

摘要:

AbstractThe possibility of direct spectrographic analysis for the routine determination of boron in steels in the range 10–150 ppm was investigated. The procedure was worked out that requires no specialized equipment, is rapid and simple, and suitable for routine control analyses when precision is not of prime importance. The method uses DC‐arc excitation of the samples in the form of powder or chips, with LiF added both as buffer and volatilizing agent. The electrodes are deep, with large capacity so that they can hold samples of about 150 mg, as the use of a large sample lowers the detection limit. The analytical line used is BI 2089.6 Å and the spectra are recorded on Ilford Q‐2 plates. One of the results of this work is a correction of the wavelength of the BII 3451

ISSN:0021-2148    

DOI:10.1002/ijch.197100091

出版商:WILEY‐VCH Verlag    

年代:1971

数据来源: WILEY

摘要:

AbstractThree distinct cobalt complexes of 2‐hydroxy‐4‐benzamidothiosemicarbazide, [Co(C8H9N4O2S) (H2O)3] Cl (I), [Co(C3H9N4O2S) (OH) (H2O)2] (II) and Na [Co(C8H9N4O2S) (OH)3] H2O (III) have been prepared at pH 3.0, 9.0 and 12.5, respectively. Magnetic measurements show subnormal values of the magnetic moment for high‐spin octahedral cobaltous complexes. A possible correlation has been sought in nephelauxetic ratio, calculated from electronic spectral data. The values of 10 Dq, L.F.S.E. and Racah's interelectronic repulsion parameters have also been evaluated. The complex (III) is diamagnetic in

ISSN:0021-2148    

DOI:10.1002/ijch.197100092

出版商:WILEY‐VCH Verlag    

年代:1971

数据来源: WILEY

摘要:

Abstract3,5‐Dihydroxy‐4‐phenylisoxazole, which is described here, is the first known 3,5‐dihydroxy derivative of isoxazole. Its unusual physical and chemical properties were studied. The tautomeric structures and the methylation products are elu

ISSN:0021-2148    

DOI:10.1002/ijch.197100093

出版商:WILEY‐VCH Verlag    

年代:1971

数据来源: WILEY

摘要:

AbstractHumic acids were extracted from Ah horizons of a Solonetz, a Solod, and a Chernozem soil. A portion of each extracted humic acid was methylated in order to make it more resistant to attack by electrophilic KMnO4. Both the methylated and unmethylated humic acids were then oxidized with KMnO4. The oxidation products were extracted into ethyl acetate and separated by preparative gas chromatography into relatively pure components, which were then analyzed by mass spectrometry and micro‐infrared spectrophotometry. A matching of the mass and IR spectra and gas chromatographic retention times of the isolated components with those of authentic specimens led to their identification.The most prominent compounds produced by the oxidation of methylated humic acids were 1,3,5‐benzenetricarboxylic acid and a complex phenolic acid, tentatively identified as propanone‐hydroxy‐methyl acetoxy‐benzene‐dicarboxylic acid. These two compounds accounted for between 18 and 23% of the original methylated humic acids. The main products resulting from the oxidation of unmethylated humic acids were benzenetri‐, benzenetetra‐ and benzenepenta‐carboxylic acids, which constituted between 10 and 12% of the weights of the original unmethylated humic acids. The results show that methylation of humic acids prior to oxidation is a useful procedure which substantially increases the yields and types of oxidation products. From the similarities in analytical data and in the quality of the oxidation products, we conclude that the three humic acids have similar chemical structures, yielding benzenecarboxylic and phenolic acids on oxidation. These compounds either originate from more complex structures or they exist in the humic acids in the forms in which they were isolated, held together

ISSN:0021-2148    

DOI:10.1002/ijch.197100094

出版商:WILEY‐VCH Verlag    

年代:1971

数据来源: WILEY

摘要:

AbstractSteranes (cholestane, stigmastane) and triterpanes (lupane, gammacerane) were identified in a bitumen obtained from a shale of Nebi Musa, near Jericho, using combined gas‐liquid — mass spectroscopic techni

ISSN:0021-2148    

DOI:10.1002/ijch.197100095

出版商:WILEY‐VCH Verlag    

年代:1971

数据来源: WILEY

摘要:

AbstractAdsorption of benzidine on montmorillonite (bentonite) particles suspended in aqueous solutions was studied by measuring the absorbance of the solution at 280 nm before and after mixing the two reactants. Benzidine adsorption decreased with an increase of suspension pH from 7 to 9.3. NaCl and calgon (Na‐hexametaphosphate) decreased the adsorption, the latter being more effective at the equivalent concentration. The interaction between benzidine and montmorillonite was connected to cation exchange processes and was influenced by the specific adsorption of the metaphosphate ion on the crystal edge

ISSN:0021-2148    

DOI:10.1002/ijch.197100096

出版商:WILEY‐VCH Verlag    

年代:1971

数据来源: WILEY