NEW NS2 AND S'S-2 LIGANDS DERIVATIVES OF PYRIDINE AND THIOPHENE INCORPORATING ICOSAHEDRAL CARBORANES

New ligands incorporating carboranyl units in organic fragments NS2 (p yridine-dithia) or S'S-2 (thiophene-dithia) have been synthesized. The close species of these ligands were obtained by the reaction of sodiu m thiolate-o-carborane with the corresponding difunctional electrophil e derivatives of pyridine or thiophene. Partial degradation of the clo se species derivatives of pyridine was successfully achieved with KOH in ethanol at r.t. All these compounds have been characterized by chem ical analyses and NMR techniques. The H-1-NMR spectrum of the nido spe cies shows that these nido molecules are produced in stoichiometric pu rity but not in isomeric purity. The crystal structure of 2,6-bis(((1- methyl-1,2-dicarba-closo -dodecaboranyl)thio)methyl)pyridine is report ed and confirms that the carborane cages are close and connected to bo th sulfur atoms. These, through methylene bridges, are connected to th e pyridine at the 2 and 6 positions. (C) 1998 Elsevier Science S.A. Al l rights reserved.