A drastic substituent effect on the emission properties of quinone diimine models and valuable insight into the excited states of emeraldine

Abstract

The (α-NR,α′-NR,N,N′-(C₆H₄CCSiMe₃)₄)[Q] models ([Q] = –NC₆H₄N–) exhibit upper excited state emissions S_n,T_n → S₀ (n >1, R = Boc), similar to emeraldine, vs. a fluorescence S₁ → S₀ (R = H), driven by a large change in dihedral angles made by the NR–C₆H₄ and [Q] planes and intramolecular H-bonds.