{Reference Type}: Journal Article
{Title}: Engineering Soluble Diketopyrrolopyrrole Chromophore Stacks from a Series of Pd(II)-Based Ravels.
{Author}: Regeni I;Chowdhury R;Terlinden K;Horiuchi S;Holstein JJ;Feldmann S;Clever GH;
{Journal}: Angew Chem Int Ed Engl
{Volume}: 62
{Issue}: 40
{Year}: 2023 Oct 2
{Factor}: 16.823
{DOI}: 10.1002/anie.202308288
{Abstract}: A strategy to engineer the stacking of diketopyrrolopyrrole (DPP) dyes based on non-statistical metallosupramolecular self-assembly is introduced. For this, the DPP backbone is equipped with nitrogen-based donors that allow for different discrete assemblies to be formed upon the addition of Pd(II), distinguished by the number of π-stacked chromophores. A Pd3 L6 three-ring, a heteroleptic Pd2 L2 L'2 ravel composed of two crossing DPPs (flanked by two carbazoles), and two unprecedented self-penetrated motifs (a Pd2 L3 triple and a Pd2 L4 quadruple stack), were obtained and systematically investigated. With increasing counts of stacked chromophores, UV/Vis absorptions red-shift and emission intensities decrease, except for compound Pd2 L2 L'2 , which stands out with an exceptional photoluminescence quantum yield of 51 %. This is extraordinary for open-shell metal containing assemblies and explainable by an intra-assembly FRET process. The modular design and synthesis of soluble multi-chromophore building blocks offers the potential for the preparation of nanodevices and materials with applications in sensing, photo-redox catalysis and optics.