Circularly polarized luminescence of helicenes: A data-informed insight

Helicenes are an interesting scaffold for chiroptical properties and in particular circularly polarized luminescence (CPL). In this short review, we collect the luminescence (g(lum)) and absorption (g(abs)) dissymmetry factors associated to the first Cotton effect of the electronic circular dichroism (ECD) spectrum. Considering the data for 170 [n]-helicenes (n = 4-11), overall we found reasonable correlations between g(lum) and g(abs). Despite a few notable exceptions, this would confirm a similarity in the stereochemistry of the ground and emitting excited states for most helicenes. These results may be useful in rationalizing chiroptical data and help chemists in designing new helicene structures with the desired CPL properties.

Automated summary

In this short review, the authors collected the dissymmetry factors associated with the first Cotton effect of the ECD spectrum for 170 [n]-helicenes. They found reasonable correlations between luminescence and absorption, suggesting similarity in the stereochemistry of the ground and emitting excited states for most helicenes. These results can be helpful in rationalizing chiroptical data and designing new helicene structures with desired CPL properties.