Fast Magic-Angle Spinning Solid-State 1H NMR Reveals Structural Relationships in the High Explosive 2,6-Diamino-3,5-dinitropyrazine-1-oxide (LLM-105)

Abstract

1H nuclear magnetic resonance (NMR) experiments were performed on the proposed insensitive high-explosive 2,6-diamino-3,5-dinitropyrazine-1-oxide (LLM-105) at high-speed magic-angle spinning rates of up to 60 kHz. These rapid speeds produce well-resolved spectra that aid in the study of the chemical and structural properties of this material. Extraordinarily long 1H T1 values were observed for the main amine peaks from the LLM-105 explosive and can be used to differentiate between peaks from the main compound and those of impurities. Further, advanced NMR measurements and simulations reveal unique spectral properties due to the strong network of intramolecular and intermolecular hydrogen bonding and provide insights in the structure of LLM-105.