Photocontrol of the Valence Isomerization Process betweenBiradical and Quinoid by Radical-Dissociation TypePhotochromism of Phenoxyl-Imidazolyl Radical Complex

摘要

In recent years,considerable interest has been focused on the chemistry of biradicaloidspecies because of their unique electronic,optical and magnetic properties.One of themainstream studies about singlet biradicaloids is based on open-shell polycyclic aromatichydrocarbons (PAHs).Because the singlet biradical character is observed in the ground stateof PAHs,the electronic structure of PAHs can be described as a resonance hybrid of an openshellbiradical and a closed-shell quinoidal structure.On the other hand,that of the biradicaloidspossessing flexible molecular structures can be sometimes suggested as a thermal equilibratedstate between the two structures.Therefore,the investigation of the dynamics of the thermalequilibrium will provide a fundamental insight of the interaction between two electronic spins.