P.M.R. analysis of several phosphorylated aziridines

Several new phosphorylated aziridines of related structure were prepared. P.m.r. analysis via decoupling experiments provided cis H-H, trans H-H, gem H-H and PNCH coupling values. Similar to simple aziridines, the cis H-H coupling is larger than trans H-H coupling (on vicinal ring carbons) which in turn is larger than gem H-H coupling. In one example operating at 100 MHz and 0° it was possible to detect the presence of two invertomers.     

Ueber ein neues photographisches Entsilberungsverfahren. D.R.P.a

Ohne Zusammenfassung     

P. M. R. Spectroscopic Analysis of Bacterial Polysaccharides Containing Pyruvic Acid

Abstract

The characteristic p.m.r. signal at τ 8.4–8.6 given by the CH₃-C group of a pyruvic acid ketal (1-carboxyethylidene derivative)may be used to demonstrate the presence of such a substituent in polysaccharides. Similar signals are given when the pyruvic acid ketal is methylated or reduced. The method is convenient for monitoring purification procedures and chemical transformations of polysaccharides such as are involved in structural studies. In certain cases the molar ratio of pyruvic acid may be estimated.     

31P N.M.R. studies of some pseudo-halogeno-derivatives of phosphorus

Abstract

Several new pseudo-halogeno phosphorus species, including isomeric N- and O-bonded cyanato-derivatives of the PCl₆ ^? ion, cyano-derivatives of RPCl₅ ^? ions (R [dbnd] Ph or Me), and organo-phosphorus (III) cyanide adducts RP(CN)₂X^? (R [dbnd] Me, Et, Ph or C₆F₅; X [dbnd] Cl, Br or I) have been prepared in solution, and identified by means of ³¹P n.m.r. spectroscopy. Isomeric configurations in the six-coordinate species have been assigned by the method of pairwise interactions.     

Gewinnung von alkoholfreiem Aether (D. R. P. Nr. 88051)

Ohne Zusammenfassung     

An E.P.R. study of peptides after U.V. irradiation

Abstract— Various peptides of Gly, Ala, Phe, Tyr, and Trp have been irradiated with U.V. light in the solid state or in frozen aqueous solution. The radicals produced were studied by E.P.R. spectroscopy at low temperature and at room temperature. Radicals seem to occur preferentially on Gly or Ala when in the C-terminal position and there is evidence for a photosensitization of these amino acids by aromatic amino acids.     

THE STRUCTURE OF myo-INOSITOL HEXAPHOSPHATE IN SOLUTION: 31P N.M.R. INVESTIGATION

Abstract

Changes in the ³¹P n.m.r. spectrum of myo-inositol hexaphosphate at different pH reveal that the conformation of this molecule varies with its degree of protonation. Above pH 12 it has the equatorial structure (Ie), below it has the axial conformation (Ia) which it retains to pH 5 when it reverts to le on the addition of a seventh proton. These changes are explained by strong hydrogen bonding between phosphate groups. There is also evidence that at low pH (2) the molecule again reverts to la.