# Air-Stable Tetrazene Radical Cation Salts: Structural Requirements and Oxidation Catalysts

## TL;DR

Scientists created a new stable radical cation salt that can be used as an efficient catalyst for alcohol oxidation under mild conditions.

## Contribution

The first synthesis and characterization of air-stable tetrazene radical cation salts with high catalytic activity.

## Key findings

- The radical cation from DAD is air-stable for over 120 days at room temperature.
- X-ray and ESR studies showed electron delocalization in the tetrazene core and adamantane framework.
- DAD exhibits two reversible redox processes and efficient catalytic activity for alcohol oxidation.

## Abstract

In this study, stable tetrazene radical cation salts
were synthesized
and characterized for the first time. The radical cation derived from
1,2-di­(2-azaadamantan-2-yl)­diazene (DAD) was isolated as an air-stable
solid, retaining its integrity for at least 120 days at ambient temperature
(∼25 °C) and pressure. X-ray crystallography and electron
spin-resonance spectroscopy revealed the delocalization of the unpaired
electron over the tetrazene core and into the adamantane framework.
DAD undergoes two well-separated, reversible redox processes and displays
high catalytic activity for alcohol oxidation under mild conditions.
Systematic structural modifications identified the key framework features
governing the radical cation stability and catalytic performance.