High-Spin Porphyrin Polyradicals

We propose metal-free, open-shell porphyrins with at least full diradical or tetraradical characters, high-spin ground states, and highly delocalized unpaired electrons obtained via minimal modifications of porphine. Since many functional (bio)-organic compounds lack sufficient pro-aromatic parts to allow seamless aromaticity-induced polyradical design, we impose the lower-bound number of unpaired electrons by tailoring the topology of π-conjugation. The presented method, Topologically Rational Assembly of Polyradicals (TRAP), is useful for designing multifunctional magnetic compounds for organic electronics, spintronics, biosensors, single-molecule devices, etc. The TRAP method transcends classes of π-conjugated compounds, thus allowing the design of polyradicals from bioorganic conjugated systems and the tuning of their magnetic properties.