The Kröhnke synthesis of benzo[a]indolizines revisited: towards small, red light emitters

Abstract

Benzo[a]indolizines with an ordered arrangement of various electron-withdrawing substituents (NO2, CF3, CN, CO2R and COPh) were prepared directly from pyridinium salts and chloronitroarenes, allowing for refined control of the photophysical...

Controlling the fluorescence quantum yields of benzothiazole-difluoroborates by optimal substitution

“…In this framework, it is interesting to stress that first-principles calculations face exactly the same challenges as chemical intuition: whilst emission energies and band shapes can typically be predicted with sufficient reliability for dye design, 17 accurate ab initio predictions of φ f are in their infancy. [18][19][20][21][22][23][24][25][26] Likewise, one might wish to turn towards machine learning approaches, but yet again, they suffer from the same bias: reliable predictions can be obtained for wavelengths, much less so for φ f . 27,28 Among the ICT dyes, thioflavin T (TT) attracted attention as a dye used for investigating amyloid β (Aβ ) aggregation [29][30][31] but its usage is not limited to amyloids 32 .…”

Catalyst‐free oxidative [3+2]‐annulation of (2‐nitroethene‐1,1‐diyl)bis(methylsulfane) and pyridinium ylides: Efficient synthesis of (methylsulfanyl)indolizines heterocycles

“…Indolizines are privileged molecular scaffolds in synthetic heterocyclic chemistry and in drug discovery [1], being present in relevant biologically active compounds [2][3][4], and with a variety of applications in materials science owing to their prominent photophysical properties [5,6]. This type of heterocycle exhibits varied activities based on the substituted indolizines shown in Figure 1.…”

Click and shift: the effect of triazole on solvatochromic dyes

“…[1][2][3][4][5] Solvatochromic dyes show pronounced changes in these properties with solvent polarity, and has been widely used in bioimaging to study protein aggregate 6 , proteome stress, 7 lipid organisation of cell membranes, 8 detection of pathogenic bacteria, among others. 9,10 These advanced applications are based on environment-dependent biophysical parameters and require solvatochromic fluorophores suitable for imaging. Desired properties include (i) excitation in the visible region, (ii) high fluorescence quantum yields, (iii) good photostability, and (iv) high two-photon cross-sections (for multiphoton microscopy).…”