摘要:

AbstractDirect information regarding the primary process in photosynthesis is obtained by measurement of the very short‐lived primary and intermediate products with the aid of (1) flash photometry, (2) periodic flash photometry, and (3) flash manometry. The analysis of the primary process using these methods on normal plant cells and chloroplasts and on those which have been chemically or physically modified has led to the formulation of a reaction scheme for the transport of electrons in photosynthesi

ISSN:0570-0833    

DOI:10.1002/anie.196507991

出版商:Hüthig&Wepf Verlag    

年代:1965

数据来源: WILEY

摘要:

AbstractThe intensity of electrons scattered by a gas can be calculated with classical as well as with quantum‐mechanical methods. The range of validity of the equations obtained can be found experimentally. Comparison of the calculated and empirical intensity or radial distribution curves allows the determination of the structure and amplitudes of vibration of a molecul. – For example, it has been found that the two bromine atoms in cis‐1, 3‐dibromocyclobutane occupy equatorial positions. The benzene rings in biphenyl derivatives are inclined at about 45° to each other. In biscyclopentadienylberyllium, the metal atom is not located midway between the t

ISSN:0570-0833    

DOI:10.1002/anie.196508191

出版商:Hüthig&Wepf Verlag    

年代:1965

数据来源: WILEY

摘要:

AbstractA few examples of preparatively useful syntheses using alkylidenephosphoranes and substances containing a CN or CC double bond are the preparations of olefins, allenes, pyran derivatives, and cyclopropane derivatives. Olefins, ketones, and monocyclic compounds can be obtained by autoxidation of alkylidenephosphoranes; α, β‐dioxo compounds (including cyclicones) can be prepared by oxidation with peroxy‐acids. Alkylidenephosphoranes can also be used for the synthesis of azines and Schiff bases. Of the many possibilities offered by the Wittig reaction, only the preparation of tritiated aldehydes and olefins will be c

ISSN:0570-0833    

DOI:10.1002/anie.196508301

出版商:Hüthig&Wepf Verlag    

年代:1965

数据来源: WILEY

摘要:

AbstractAn apparatus first described in 1961 for the measurement of circular dichroism down to 220 mμ has been improved and its range extended down to 185 mμ. Some examples are given in the field of dienes, conjugated ketones, and aromatic chromophores. A more extensive study of protein structures was developed with the following results: (a) helical polypeptides show a complex dichroism in the far ultraviolet with three components (192 mμ, 204 mμ, 225 mμ), characteristic of the helical array of peptide groups; (b) human serum albumin shows a very similar curve of dichroism and is 60% helical; (c) urea denaturation, as judged by dichroism, is a reversible phenomenon; (d) a solvent such as chloroethanol increases the helical content of human serum albumin and clupein and has only a very small action on poly‐L‐glutamic acid; (e) the rupture of SS bonds in human serum albumin favors the attack of denaturing agents such as urea; (f) detergents help to maintain the rigid structure of human serum albumin after the rupture of

ISSN:0570-0833    

DOI:10.1002/anie.196508381

出版商:Hüthig&Wepf Verlag    

年代:1965

数据来源: WILEY

摘要:

AbstractThe principal physiological function of lipoic acid appears to be its action as coenzyme in the oxidative decarboxylation of α‐oxo acids. In order to find out whether lipoic acid is essential to higher organisms, structurally modified lipoic acids were prepared as potential antagonists. Only 4‐oxalipoamide promotes the growth of S. faecalis 8043; the other substances tested are inactive or else inhibit growth. In experiments to determine the substrate specificity of lipoamide oxidoreductase and its inhibition by structurally modified lipoic acids, no strong inhibitors were discovered. –; Ring strain, spectra, and ring cleavage of compounds containing the 1, 2‐dithiolane ring are discussed in relation to the biological function and the reactivity of lip

ISSN:0570-0833    

DOI:10.1002/anie.196508461

出版商:Hüthig&Wepf Verlag    

年代:1965

数据来源: WILEY

摘要:

AbstractThe more recent applications of electron paramagnetic resonance (EPR) to organic chemistry include the investigation of triplet states, donor‐acceptor complexes, short‐lived free‐radical intermediates, and reaction kinetics. The principles of the theoretical calculations required to obtain the maximum information from EPR spectra are outlined for free radicals containing π‐electron systems. EPR intensities, line widths, hyperfine splitting, and g factors permit the determination of free‐radical yields, ionic charges, rotation frequencies in rotamers, electron density distributions, electronegativities, intramolecular torsion angles, solvent effects (resulting from hydrogen bonding), and π‐orbital energies. – The production of free radicals with the aid of initiation reaction in flow systems, by irradiation, and by electrolysis seems particu

ISSN:0570-0833    

DOI:10.1002/anie.196508561

出版商:Hüthig&Wepf Verlag    

年代:1965

数据来源: WILEY

ISSN:0570-0833    

DOI:10.1002/anie.196508682

出版商:Hüthig&Wepf Verlag    

年代:1965

数据来源: WILEY

ISSN:0570-0833    

DOI:10.1002/anie.196508693

出版商:Hüthig&Wepf Verlag    

年代:1965

数据来源: WILEY

ISSN:0570-0833    

DOI:10.1002/anie.196508701

出版商:Hüthig&Wepf Verlag    

年代:1965

数据来源: WILEY

ISSN:0570-0833    

DOI:10.1002/anie.196508712

出版商:Hüthig&Wepf Verlag    

年代:1965

数据来源: WILEY