Formation of Polyborates during Dimerization of the closo-Decaborate Anion and Isomerization of the Octadecahydroeicosaborate Anion

Abstract

Abstract The structures of cesium and tetraphenylphosphonium polyborates obtained in the course of mild oxidation of the closo-decaborate anion [B10H10]2– in water with a cerium(IV) salt to form Cs2[trans-B20H18] as the main product and in the course of long-term isomerization of the [trans-B20H18]2– anion under the action of UV irradiation to form (Ph4P)2[iso-B20H18] as the main product have been studied. The compounds have been isolated as solvates Cs[B5O6(OH)4]·2H2O and PPh4[B5O6(OH)4]·2DMF·H2O from the filtrates obtained after removing the target compounds from the reaction solutions. The formation of polyborates is explained by the processes of degradation of boron cluster anions in reaction solutions over time.