RESOLUTION ET AFFINEMENT DE LA STRUCTURE DU COMPOSE BIS-(SALICYLATE) DE TRIPHENYLBISMUTH.

Abstract

Since the advent of the computer tools, and the increasing performance of the apparatuses of diffraction of x-rays, the determination of the crystalline structure of the monocrystals, starting from the data of x-rays, remains the method easiest and most effective to implement to characterize the structural properties of the crystalline solids. Starting from a spectrum of diffraction of x-rays correctly recorded and treated, it is possible to reach the resolution of the crystalline structure by various methods, then with the refinement of the structure obtained. The determination of the crystalline structure by diffraction of x-rays high-resolution on monocrystal of a compound of the family of the organobismuths (V) of chemical formula C32 H25 Bi O6 is done in 2 stages, the resolution, the refinement of the structure and the structural analysis of the molecule. During the resolution and the refinement of the structure, one used the two following programs respectively: [SHELXS], [SHELXL]. The resolution of the structure leads to the coordinates of the atomic positions xj, yj, zj but most interesting for us chemists it is the provision of the atoms the ones compared to the others. For this purpose, one describes the structure by these lengths of connections and angles of valence as well as the angles of torsion. The results obtained (distance, angle of valence, angle of torsion) show the stability of the structure selected, testify to quality to the spectrum to diffraction to x-rays recorded and also the effectiveness to the formalism to data processing used (formalism of Blessing).