2-(5-Nitroiminotetrazol-1-yl)acetic acid (4) was synthesized from 100% nitric acid and ethyl 2-(5-aminotetrazol-1-yl)acetate (2), which was easily obtained by reaction of ethyl aminoacetate hydrochloride, sodium hydroxide, and cyanogen azide. Compound 4 was also formed with 100% nitric acid and 2-(5-aminotetrazol-1-yl)acetic acid which was prepared from sodium 5-aminotetrazolate and 2-chloroacetic acid. New energetic materials comprised of nitroiminotetrazolate salts with nitroiminotetrazolate and carboxylate anions have been characterized spectroscopically as well as with single crystal X-ray diffraction and elemental analyses. In addition, the heats of formation (ΔH_f), and detonation pressures (P) and velocities (D) were calculated. All compounds were insensitive (>40 J) for impact with BAM Fallhammer.