Recent process and development of metal aminoborane.

This Review focuses on the development of metal aminoboranes; it discusses their synthesis, structure, chemical characterization, and applications. The lightweight nature of the molecules, the simplified procedures for the synthesis of the target compounds, the reversibility of hydrogen storage and dehydrogenation, and in-depth research on the mechanism of the thermal decomposition are also discussed. A major challenge that still remains is how to combine the advantages of the compounds to produce a material that is not only able to release and absorb hydrogen under atmospheric conditions, but is also lightweight with a stable molecular structure. Finally, some future trends and perspectives in these research areas will be outlined.

Theoretical study on novel nitrogen-rich energetic compounds of bis(amino)-azobis(azoles) with tetrazene unit.

Six stereoisomers of 5,5'-bis(amino)-1,1'-azobis(tetrazoles) and 30 other structures, including all possible bis(amino)-azobis(azoles) with an N-N=N-N unit, were designed. The molecular geometries were fully optimized at the DFT-B3LYP level with the 6-31++g (d, p) basis set. From the absence of any imaginary frequency in the infrared vibration frequency spectrum, it is predicted that all these studied structures may exist in stable forms. The results of the total energies of the stereoisomers of 5,5'-bis(amino)-1,1'-azobis(tetrazoles) indicate that the two symmetric trans-form structures are more likely to exist than the other four. The pyrolysis process, chemical stability and molecular electrostatic potential were studied via the investigation of their electronic structure. Heats of formation (HOFs) were calculated using the atomization energy method based on the results of the harmonic vibration frequencies, and a linear relationship was found between the HOF and nitrogen chain or nitrogen content. Densities of the title compounds were predicted with the Monte Carlo method. Finally, according to the results of the calculated HOFs and densities, the explosive parameters of these compounds were calculated using the Kamlet-Jacobs formula. 5,5'-Bis(amino)-1,1'-azobis(tetrazoles) and its isomer 5,5'-bis(amino)-2,2'-azobis(tetrazoles) may have potential for use as energetic compounds.