Optoelectronic Tuning of Organoborylazadipyrromethenes via Effective Electronegativity at the Metalloid Center

Organoborylazadipyrromethenes
were synthesized from free base and fluoroborylazadipyrromethenes
and characterized with regard to their structural and electronic properties.
B–N bond lengths, along with photophysical and redox behavior,
appear dependent on the effective electronegativity at the boron atom
as tuned by its substituents, with stronger electronegativity correlating
to a shorter B–N bond length, red-shifted absorbance, enhanced
fluorescence lifetime and yield, and positively shifted redox potentials.