Dibenzonaphthyridinones: Heterocycle-to-Heterocycle Synthetic Strategies and Photophysical Studies

A heterocycle-to-heterocycle
strategy is presented for the preparation
of highly fluorescent and solvatochromic dibenzo­naph­thyridinones
(DBNs) via methodology that leads to the formation of a tertiary,
spiro-fused carbon center. A linear correlation between the results
of photophysical experiments and time dependent density functional
theory calculations was observed for the λmax of
excitation for DBNs with varying electronic character.