Bis-periazulene (Cyclohepta[<i>def</i>]fluorene) as a Nonalternant Isomer of Pyrene: Synthesis and Characterization of Its Triaryl Derivatives
Koki Horii, Ryohei Kishi, Masayoshi Nakano, Daisuke Shiomi, Kazunobu Sato, Takeji Takui, Akihito Konishi, Makoto Yasuda
Abstract
Bis-periazulene (cyclohepta[def]fluorene), which is an unknown pyrene isomer, was synthesized as kinetically protected forms. Its triaryl derivatives 1c–e exhibited the superimposed electronic structures of peripheral, polarized, and open-shell π-conjugated systems. In contrast to previous theoretical predictions, bis-periazulene derivatives were in the singlet ground state. Changing an aryl group controlled the energy gap between the lowest singlet–triplet states.
Topics & Concepts
ChemistryFluorenePyreneSinglet stateConjugated systemPhotochemistryArylGround stateStereochemistryOrganic chemistryExcited stateAtomic physicsPhysicsAlkylPolymerSynthesis and Properties of Aromatic CompoundsOrganic Electronics and PhotovoltaicsLuminescence and Fluorescent Materials