Photochemical synthesis of carbazole-fused Blatter radicals: effective spin injection to the carbazole system
Paulina Bartos1, Patrycja Szamweber2, Bruno Camargo3
1Faculty of Chemistry, University of Lodz 91-403 Lodz Poland piotr.kaszynski@cbmm.lodz.pl.
Abstract:
Photocyclization of N-substituted carbazole derivatives of benzo[e][1,2,4]triazine gave two carbazole-fused Blatter radicals with a novel heterocyclic skeleton. No photocyclization was observed for the analogous dibenzocarbazole, indole, benzimidazole, and phenoxazine precursors, which was rationalized with DFT computational methods. The two carbazole-derived radicals were characterized by spectroscopic (UV-vis, EPR) and electrochemical methods, while one of them was analyzed structurally (XRD) and magnetically (SQUID). The latter analysis revealed ferromagnetic interactions in the solid state with 2J/k B = 16.6 K. Properties of these first examples of a new class of stable radicals were analyzed with DFT methods, which confirmed significant impact of the peri-nitrogen atom on electronic properties and additional 15% spin delocalization.
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