<i>N</i> -Methylene-C Linked 4-Hydroxy-3,5-dinitropyrazole and <i>N</i> -Hydroxytetrazole: Insensitive Energetic Materials Enlivened by <i>N</i> -Hydroxyl Group

Optimization of oxygen balance without jeopardizing stability is one of the key objectives in synthesizing nitrogen-rich high-performing energetic materials. In this regard, choosing scaffolds with good nitrogen and oxygen content, along with the possibility of stabilizing interactions, becomes crucial. In this work, powerful insensitive energetic materials were synthesized by connecting a 4-hydroxy-3,5-dinitropyrazole (HODNP) moiety with <i>N</i>-hydroxytetrazole via <i>N</i>-methylene-C bridge. Compound <b>5</b> showed the rare ability to form selective monocationic (<b>6</b>-<b>9</b>) and dicationic (<b>10</b>-<b>13</b>) energetic salts, providing options for fine-tuning energy and stability properties. These <i>N</i>-hydroxytetrazole-based compounds exhibit overall better energy and stability properties than the analogous tetrazole-based compounds. Energetic salts <b>7</b>, <b>8</b>, <b>11</b>, and <b>12</b> exhibited excellent detonation performance, comparable or superior to benchmark explosive RDX.