Synthesis, spectroscopic and thermal characterization on non-metal cation (NMC) pentaborate salts containing cations derived from histidine and arginine

The new non-metal cation (NMC) pentaborate structures of cationic histidine and arginine aminoacids were synthesized and characterized using spectroscopic (11B NMR and IR) methods. Their thermal properties have been investigated by TG/DrTG-DTA. The histidine NMC pentaborate, [C6H10N3O2][B5O6(OH)4].4H2O and the arginine pentaborate, [C6H13N4O2][B5O6(OH)4]2.3H2O are formulated with 4 and 3 waters of crystallization, respectively. The histidine pentaborate is more stable than the arginine pentaborate to thermal decomposition, but both decompose thermally via initial dehydration followed by loss of amino acid fragments to afford glassy B2O3.