Excited state dynamics of PPI dendrimers functionalized with 4-(4′-ethoxybenzoyloxy)salicylaldehyde chromophores

► Opening of pseudo-aromatic ring takes place in excited PPI-SA dendrimers. ► Excited closed form tautomers relax to conformationally distorted trans-keto form. ► Trans-keto tautomers relax to the ground state without conformational changes. ► Excited state dynamics of PPI-SA dendrimers depends on their generation.