Facile Synthetic Routes to Phenylene and Triazine Core Based Dendritic Cobaltabisdicarbollides

The synthesis and thermal properties of phenylene and triazine core based symmetrical macromolecules containing three to six cobaltabis(dicarbollide) clusters are reported. The zwitterionic oxonium derivative of cobaltabis(dicarbollide), [3,3'-Co(8-C4H8O2-1,2-C2B9H10)(1',2'-C2B9H11)], has been used for the synthetic transformations, and silicon tetrachloride and triflic acid were used as the cyclotrimerization reagents. Compounds containing multiple cobaltabis(dicarbollide) clusters are found to be extremely thermally stable, and only a 10-30% mass loss occurred up to 700 degrees C.