Polarization and Symmetry of Electronic Transitions in Long Fluorescence Lifetime Triangulenium Dyes

Abstract

To fully exploit the capabilities of fluorescence probes in modern experiments, where advanced instrumentation is used to probe complex environments, other photophysical properties than emission color and emission intensity are monitored. Each dye property can be addressed individually as well as collectively to provide in-depth information unavailable from the standard intensity measurements. Dyes with long emission lifetimes and strongly polarized transitions enable the monitoring of lifetime changes as well as emission polarization (or anisotropy). Thus experiments can be designed to follow slow dynamics. In this article the UV and visible electronic transitions of a series of red emitting dyes based on the triangulenium motif are investigated. We resolve overlapping features in the spectra and assign transition moment of the molecular axes. The result is the complete Jablonski diagram for the UV and visible spectral region. The symmetries of the studied dyes are shown to have a large influence on the optical response and they are clearly separated into two groups of symmetry by their photophysical properties. The C2v symmetric dyes: azadioxatriangulenium (ADOTA+) and diazaoxatriangulenium (DAOTA+) have high emission anisotropies, fluorescence lifetimes around 20 ns, and fluorescence quantum yields of ~50%. The trioxatriangulenium (TOTA+) and triazatriangulenium (TATA+) dyes—nominally of D3h symmetry—have fluorescence lifetimes around 10 ns lifetimes and fluorescence quantum yields of 10-15%. However, the D3h-symmetry is shown to be lowered to a point group, where the axes transform uniquely such that the degeneracy of the E’-states is lifted.

Sandwich type plasmonic platform for MEF using silver fractals

“…Figure 2 C shows the lifetime histogram of ADOTA sample on glass with lifetime from about 8 ns to 20 ns having relatively broad distribution. The reduced lifetime on glass (12.8 ns) compared to bulk solution (~20 ns) is expected due to quenching by oxygen, freely diffusing into the thin film, and possible aggregation in the concentrated sample in small area [26,27] Moreover, when ADOTA sample was placed in contact with fractals non-uniform fluorescence intensity enhancement was observed as shown in Figure 3 A. Two populations of enhanced fluorescence are clearly visible namely bright white spots and relatively uniform grey areas.…”

Evaluation and Optimization of Three Different Immunoassays for Rapid Detection Zearalenone in Fodders

“…However, the fluorescent tracer may specifically bind to the matrix of the sample and lead to an increased fluorescence polarization value (Mi et al 2013). The use of new fluorescent dyes, such as long wavelength fluorescent dyes, quantum dot and lanthanide, may be the solutions to improve the precision and stability of FPIA (Beloglazova et al 2016;Thyrhaug et al 2013;Tian et al 2012). In addition, portable FP instrument Sentry-200 could be carried to the trading or production site testing.…”

Azadioxatriangulenium: Synthesis and Photophysical Properties of Reactive Dyes for Bioconjugation

“…[7] One characteristic property of the ADOTA chromophore is the rare combination of relatively low oscillator strengths of the emissive transition and high fluorescence quantum yields, which gives rise to fluorescence lifetime of 10 – 20 ns, despite the relatively low energy gap between the ground state and the first excited state. [8] The result is an efficient long fluorescence lifetime fluorophore with emission in the red part of the visible spectrum.…”