Up to the last years, the perchlorate anion, as a coordinating agent was scarcely known at all. The discovery of the ionic structure of the chlorine trioxides ClO2+ ClO4- has confirmed its perchlorating part and has permitted to consider again the synthesis of anhydrous perchlorates. From 1975 to 1980 characterization of 25 new anhydrous perchlorato metals or perchlorato metallates in our laboratory was a contribution to the destruction of the myth: ClO4 is a non coordinating anion. The binding of the ligand to the metal is determined by Infrared and Raman Spectroscopy and by X ray diffraction for [Sn2O3(ClO4)4]2. This study permits to propose for all the synthetized compounds molecular structures in which the ClO4 ligand is monodentate or bidentate.
M. Chaabouni, J. L. Pascal, J. Potier
Pages 3 - 10
Des alcoxyétains du type R3SnOR2 et des carboxylates organostanniques du type R3SnOCOR sont synthétisés par différentes méthodes. Quelques réactions aboutissant au déplacement des groupements oxygénés sont décrites.
Pages 11 28
Using varied and complementary analytical technics, we have characterized biochemically two molecular forms for nuclease of Staphylococcus aureus (Foggi strain). The results obtained show clearly that nuclease I differs from nuclease II by the loss of one dipeptide beside N. terminal. This loss doesn’t seem affect the enzymatic activity since the two forms have the same specific activities towards the DNA and the RNA. Several hypothesis have been advanced to render an account of the whole of results.
N. Marrakchi-Mzid, P. Cozzone
Pages 29 - 42
A 13C NMR study of 23 indole alkaloids from iboga-type has permitted the chemical shifts of ail carbon to be established. Among those alkaloids, five were hemisynthesised, and the others were extracted from Bonafousia tetrastachya, Anartia olivacea, Anartia meyeri and Peschiera echinata (Apocynaceae).
F. Ladhar, N. Ghorbel, M Damak
Pages 43 - 56
The isolation of scopolamine 1 and hyoscyamine 2 from the seeds of Datura metel (Solanaceae) is described. Their 13C NMR study has permitted the chemical shifts of all carbon to be attributed.
A. Triki, M. Damak
Pages 57 - 61