Mechanochemically Assisted Synthesis of Hexaazatriphenylenehexacarbonitrile

Abstract

1,4,5,8,9,11-hexaazatriphenylenehexacarbonitrile (HAT CN) was synthesized mechanochemically at room temperature. The coupling of hexaketocyclohexane and diaminomaleonitrile was conducted in 10 min by vibratory ball milling. The effects of milling parameters, acids, dehydrating agents, and liquid-assisted grinding were rationalized. With 67%, the yield of this mechanochemical approach exceeds that of state-of-the-art wet-chemical syntheses while being superior with respect to time-, resource-, and energy-efficiency as quantified via green metrics.

Figure 1

Synthetic pathway to obtain HAT-CN. Hexaketocyclohexane and diaminomaleonitrile are coupled in a condensation reaction with subsequent oxidation steps.

Figure 2

Spectroscopic analysis of HAT-CN. (A) ¹³C{¹H} NMR (300 MHz, CO(CD₃)₂) spectrum of pure HAT-CN. (B) IR spectrum of HAT-CN. (C) Stacked Raman spectra of HAT-CN and the starting materials used in the synthesis of HAT-CN. (1) Raman spectrum of HAT-CN. (2) Raman spectrum of hexaketocyclohexane. (3) Raman spectrum of diaminomaleonitril.