Tip-Induced Nitrene Generation

We generated trinitreno-<i>s</i>-heptazine, a small molecule featuring three nitrene centers, by tip-induced chemistry from the precursor 2,5,8-triazido-<i>s</i>-heptazine on bilayer NaCl on Au(111). The precursor's azide groups were dissociated to form mono-, di- and trinitreno-<i>s</i>-heptazine, yielding molecules with one to three nitrene centers. The precursor and its products are characterized by atomic force microscopy and scanning tunnelling microscopy. Broken-symmetry DFT and configuration interaction calculations of inter-nitrene and intra-nitrene exchange couplings suggest a ferromagnetic coupling of the <i>S</i> = 1 nitrene centers, resulting in a high-spin septet ground state for neutral trinitreno-<i>s</i>-heptazine in the gas phase. On bilayer NaCl on Au(111), the combined results of experiments and theory suggest trinitreno-<i>s</i>-heptazine to be an anion with a sextet ground state.