The Photophysics of Dibenzo[a,j]phenazine

Abstract

The photophysics of dibenzo [a,j]phenazine (DBPHZ) in solution was investigated by steady-state and time-resolved spectroscopy. The nature of the solvent (methanol, acetonitrile, dichloromethane and cyclohexane were considered) only weakly affects the photophysical properties. The first excited singlet state features a lifetime of the order of 1 ns. Its fluorescence emission is centered around 420 nm and occurs with moderate yields of � 0.1. The lowest triplet state is populated with yields of � 0.3. Quantum chemical computations suggest that a 3 np * state energetically close to the primarily excited singlet state is responsible for the efficient intersystem crossing towards the triplet manifold.

Femtosecond Spectroscopy on a Dibenzophenazine‐Cored Macrocycle Exhibiting Thermally Activated Delayed Fluorescence

“…Cyclohexane (CX, permittivity $${{\rm{{\rm \epsilon} }}_r = }$$ 2.02) and toluene (Tol, $${{\rm{{\rm \epsilon} }}_r = }$$ 2.37) were chosen as representatives for non‐polar solvents, tetrahydrofuran (THF, $${{\rm{{\rm \epsilon} }}_r = }$$ 7.43) as a polar aprotic one. For comparison with an earlier study on the DBPHZ acceptor chromophore, [13] measurements in acetonitrile would have been advantageous, too. Unfortunately, compound 1 can not be dissolved in this solvent.…”

Design strategies and applications of novel functionalized phenazine derivatives: a review

“…In addition to this, some molecules containing dibenzo[a,j]phenazine also presented mechanochromic luminescence (MCL), enriching the field of applications to chemical sensors, data storage devices and security inks. [154][155][156][157][158][159][160][161][162][163] Besides that, Takeda and Gilch et al 164 systemically investigated the photophysics of the dibenzo[a,j]phenazine by steady-state and time-resolved spectroscopy. In fact, the polarity of the solvent only weakly affected the photophysical properties of dibenzo[a,j]phenazine.…”

Modulating the Photophysical Properties of Twisted Donor–Acceptor–Donor π-Conjugated Molecules: Effect of Heteroatoms, Molecular Conformation, and Molecular Topology

“…In 2014, we discovered a novel oxidative skeletal rearrangement of 1,1′-binaphthalene-2,2′-diamines and developed a synthetic method to access U-shaped dibenzo­[ a , j ]phenazines (DBPHZ), a compound class that is challenging to synthesize through conventional organic reactions (Scheme ). These newly synthesized aza-polycyclic hydrocarbon molecules feature a distinct U-shaped structure, photoluminescent properties, , and high electron affinities . Leveraging the electron-deficient and luminescent characteristics and halogeno functionality introduced at the periphery of the DBPHZ, we have developed a diverse array of DBPHZ-cored D–A–D emitters.…”