Exciplex-like emission from a closely-spaced, orthogonally-sited anthracenyl-boron dipyrromethene (Bodipy) molecular dyad

Abstract

A molecular dyad, , has been prepared that incorporates a boron dipyrromethene (Bodipy) group functionalized at the meso position with an anthracenyl unit. Emission from the dyad contains contributions from both localized fluorescence from the Bodipy unit and exciplex-like emission associated with an intramolecular charge-transfer state. The peak position, intensity and lifetime of this exciplex emission are solvent dependent and the shift in the emission maximum shows a linear relationship to the solvent polarity function (Deltaf). The calculated dipole moment for the exciplex is 22.5 +/- 2.2 D. The radiative rate constant (k(RAD)) for exciplex emission decreases progressively with increasing solvent polarity. In this latter case, k(RAD) shows an obvious dependence on the energy gap between the exciplex state and the first-excited singlet state resident on the Bodipy unit. The emission characteristics for dissolved in perfluorooctane are used to characterize the refractive index and dielectric constant of the solvent.

Aggregation‐Induced Singlet Oxygen Generation: Functional Fluorophore and Anthrylphenylene Dyad Self‐Assemblies

“…Benniston et al. reported that a dyad of BODIPY and anthracene exhibited an exciplex‐like emission assigned to the intramolecular CT state . They remarked that a CT emission was not observed for 1,3,5,7‐tetramethyl BODIPY due to the restricted rotation between the BODIPY and phenylene ring .…”

“…Benniston et al reported that ad yad of BODIPY and anthracene exhibited an exciplex-like emission assigned to the intramolecular CT state. [18] They remarked that aC Te mission was not observed for 1,3,5,7-tetramethyl BODIPYd ue to the restricted rotation between the BODIPY and phenylene ring. [19] Since both BODIPY-AP and BODIPY-MeAP can rotate around the phenylene ring to ac ertain extent,t he red emissions observed in toluene and 1,4-dioxane are assigned to at wisted intramolecular CT (TICT) state delocalized over the BODIPY and anthracene moieties.…”

4,4′-Difluoro-4-bora-3a,4a-diaza-s-indacenes (BODIPYs) as components of novel light active materials

“…22) has the anthracene unit attached directly to the 5-position of the BODIPY. 56 Despite the lack of methyl groups on the BODIPY core, the anthracene unit adopts a near-orthogonal geometry with respect to the BODIPY plane. This was also observed in the 1,3,5,7-tetramethyl analogue of the same BODIPY.…”

Control of triplet state generation in heavy atom-free BODIPY–anthracene dyads by media polarity and structural factors

“…In comparison, the structure of 1, with unsubstituted BODIPY and anthracene moieties, exhibited the largest C8─C15 bond length (1.501 Å). 43 Two major forms of crystal packing were found for the BAD systems. The first is the head-to-head arrangement, as for 2 ( Figure S29).…”