Chiral Diketopyrrolo[3,4-c]pyrrole-1,2,3-1H-triazole Dyes with Highly Tuneable Properties in Solution and Thin Films.

We have studied the impact of achiral substituents on the chiral supramolecular architectures of diketopyrrolo[3,4-c]pyrrole-1,2,3-1H-triazole (DPP) dyes. We decorated the same chiral DPP motif with substituent groups on the nitrogen atoms of the lactam moiety: the hydrophobic n-octyl alkyl chain, the hydrophilic tri(ethylene glycol) (TEG) chain and the thermo-cleavable tert-butoxycarbonyl (t-Boc) carbamate group. In spite of having identical conjugated chromophore and chiral appendages, in aggregated form the three dyes displayed profoundly different optical, chiroptical, electrochemical and thermal features. ECD measurements revealed differences in the aggregation modes, which would be inaccessible by most other techniques. We found strong chiroptical features, which would have major implications in the context of chiral organic opto-electronics and in the development of other highly innovative technological applications.