Hetero Cu(III)–Pd(II) Complex of a Dibenzo[g,p]chrysene-Fused Bis-dicarbacorrole with Stable Organic Radical Character

• DOI: 10.1021/jacs.7b09167
• Publication Date: 2017-09-30T17:09:16Z
• Authors: Xian-Sheng Ke; Yongseok Hong; Peiyu Tu; Qing He; Vincent M. Lynch; Dongho Kim; Jonathan L. Sessler
• Keywords: Antiaromaticity; Radical ion; Chrysene; Imine; Moiety

Bis-dicarbacorrole (bis-H3) with two adj-CCNN subunits was synthesized by incorporating a dibenzo[g,p]chrysene moiety into the macrocyclic structure. The trianionic cores in bis-H3 can stabilize Cu(III) ions (bis-Cu) or concurrently cation and Pd(II) ion form of hetero bis-metal complex (mix-Cu/Pd). As prepared, mix-Cu/Pd displays organic π radical character, as confirmed various techniques, including electron paramagnetic resonance spectroscopy, cyclic voltammetry, femtosecond transient absorption measurements, DFT calculations. Radical formation is ascribed to one-electron transfer from dicarbacorrole backbone Pd center allowing d8 be accommodated square planner coordination geometry. Nucleus-independent chemical shift anisotropy induced current density calculations provide support for conclusion that bis-Cu both display antiaromatic character contain formally 16 π-electron subunits. On this basis, we suggest best considered containing fused 15 nonaromatic subunit subunit. spectroscopic observations are consistent these assignments.