Spectroscopic studies on carborane derivatives: Synthesis and characterization of partial cage degradation reactions of 1,2-(hydroxymethyl radical)-closo-carborane with 2-(aminomethyl)-pyridine

The purpose of this study was to synthesize related (aminoalkyl)-derivatives of carboranes and metallacarboranes. We attempted to substitute the hydroxyl groups in 1,2-bis(hydroxymethyl)-o-carborane with 2-(aminomethyl)-pyridine, and prepare the cobalt(II) complex. The addition of the 2-(aminomethyl)-pyridine did not lead to the displacement of the hydroxyl groups, but rather, the cage degradation of 1,2-(CH2OH)2- closo-1,2-C2B10H10 as the zwitterion [7,8-(CH2OH)2-nido-7,8-C2B 9H10]- and B(C5H4CH 2NH3+), which was confirmed through 1H, 11B, 13C NMR and IR spectral analysis. The attempted conversion of 1,2-(CH2OH)2-closo -1,2-C2B10H10 to an aminomethyl pyridine derivative through transformation of the diol to the bromide followed by nucleophilic displacement with 2-aminomethyl pyridine was inconclusive. Future work will include the purification of the products for Scheme 2 and determining the reaction mechanisms for Scheme 3. Overall, this research study contributes to the growing subfield of the chemistry of carboranyl amines.