1-Methyl-5-aminotetrazole (
4, MAT) can easily be protonated by strong acids, yielding known but largely uninvestigated1-methyl-5-aminotetrazolium nitrate (
4a) and perchlorate (
4b). Methylation, rather than protonation, of
4 withiodomethane followed by the exchange of the iodide (
5a) for nitrate (
5b), perchlorate (
5c), azide (
5d), and dinitramide(
5e) yields a new family of energetic methylated aminotetrazole salts. In all cases, stable salts were obtained andfully characterized by vibrational (IR, Raman) spectroscopy, multinuclear NMR spectroscopy, mass spectrometry,elemental analysis, and X-ray structure determination. Compounds
4a,
4b, and
5c crystallize in the monoclinicspace group
P2
1/
n, whereas compounds
5b and
5e crystallize in the orthorhombic space group
P2
12
12
1 and
5d inthe orthorhombic
Fddd. Initial safety testing (impact, friction, and electrostatic sensitivity) and thermal stabilitymeasurements (DSC) were also carried out. The MAT salts all exhibit good thermal stabilities (decompositionabove 150
C). The constant volume energies of combustion (
cU) of
4a,
5b,
5d, and
5e were determined to be-2510(10) cal/g, -3190(30) cal/g, -4500(100) cal/g, and -2570(70) cal/g, respectively, experimentally using oxygenbomb calorimetry. From the experimentally determined density, chemical composition and energies of formation(back calculated from the heats of combustion), the detonation pressures and velocities of
4a (8100 m/s, 25.6GPa),
5b (7500 m/s, 20.2 GPa),
5d (8200 m/s, 21.7 GPa), and
5e (7500 m/s, 21.2 GPa) were predicted using theEXPLO5 code.