ADDUCTS OF TIN(IV) AND ORGANOTIN(IV) DERIVATIVES WITH 2,2'-AZOPYRIDINE .2. CRYSTAL AND MOLECULAR-STRUCTURE OF SNME2BR2AZP AND FURTHER MOSSBAUER AND PHOTOELECTRONIC SPECTROSCOPIC STUDIES

A series of adducts of tin(IV) derivatives with 2,2′-azopyridine, AZP, has been studied by Mössbauer and X-ray photoelectronic spectroscopies and the crystal and molecular structure of SnMe2Br2- AZP has been determined. The linear correlation of the Mössbauer parameter isomer shift with partial atomic charge on tin suggests the occurrence of a single homologous series of isostructural adducts. The correlation of the Mössbauer parameter quadrupole splitting and C-Sn-C bond angle permits their calculation in SnMe2X2AZP adducts (X = Cl, Br). The N1s binding energies, obtained by XPS data, pointed out two slightly different values for both pyridinic and azo-group nitrogens. The crystallographic study of the SnMe2Br2AZP adduct shows a new structure in which the Sn atom is seven-coordinated. © 1990.