Engineering Soluble Diketopyrrolopyrrole Chromophore Stacks from a Series of Pd(II)‐Based Ravels**

Abstract

A strategy to engineer the stacking of diketopyrropyrrole (DPP) dyes based on non‐statistical metallosupramolecular self‐assembly is introduced. Therefore, the DPP backbone is equipped with nitrogen‐based donors that allow for different discrete assemblies to be formed upon addition of Pd(II), distinguished by the number of π‐stacked chromophores. A Pd3L6 three‐ring, a heteroleptic Pd2L2L’2 ravel composed of two crossing DPPs (flanked by two carbazoles), and two unprecedented self‐penetrated motifs (a Pd2L3 triple and a Pd2L4 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 Pd2L2L’2 which stands out with an exceptional photoluminescence quantum yield of 52%. 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 opens potential for the preparation of nanodevices and materials with applications in sensing, photo‐redox catalysis and optics.

Heteromeric Completive Self-Sorting in Coordination Cage Systems

“…Ligands B1−3 afford classical lantern shape Pd 2 L 4 cages, 18,41,42 while A, bearing quinoline donor groups, forms an interlaced Pd 2 A 3 (MeCN) 2 (named Pd 2 A 3 S 2 in the figures) ravel with one coordination site per Pd(II) cation occupied by a solvent molecule due to geometrical constraints (represented by an A 4 assembly in the more general schemes in Figures 1 and 4). 38 When mixing Pd 2 (B1) 4 and Pd 2 (B2) 4 , we obtained a statistical mixture of assemblies Pd 2 (B1) n (B2) 4−n (n = 0−4). 27 This is not surprising, as both ligands' binding vectors are nearly identical due to the geometrical resemblance between the backbones.…”

“…This is not surprising, as both ligands’ binding vectors are nearly identical due to the geometrical resemblance between the backbones. Both ligands B1 and B2 yield a figure-of-eight trans -heteroleptic assembly when associated with A and Pd(II) in acetonitrile . ESI-MS analysis confirmed the formation of a compound of stoichiometry Pd 2 ( A ) 2 ( B2 ) 2 , and the 1 H NMR data indicated the formation of a self-penetrating structure (Figures S2–S8 and S50 for the model).…”

“…22,32−37 Here, we present what is, to the best of our knowledge, the first example of the cage-to-cage transformation of three homoleptic metallosupramolecular assemblies to a defined mixture of two coexisting heteroleptic coordination cages (Figure 1). Moreover, while both heteroleptic assemblies share one ligand (ligand A in Figure 1; based on a diketopyrrolopyrrole 38 ), this component shows a pronouncedly different behavior in the coexisting assemblies. This type of self-sorting was described by Schmittel and coworkers as 'heteromeric completive self-sorting' 39 and is similar to a fusion of the effects of both integrative and narcissistic self-sorting.…”

Subtle adjustments for constructing multi-nuclear luminescent lanthanide organic polyhedra with triazole-based chelates

“…1–5 Within this context, 3D metallosupramolecular architectures have emerged as intriguing candidates with diverse applications. 6–16 However, while the potential of coordination-directed self-assembly is evident, the utilization of lanthanide ions in constructing such assemblies, especially high-nuclear assemblies, has faced unique challenges. 17 Lanthanides exhibit remarkable spectroscopic and electromagnetic properties that make them attractive building blocks; 18–21 however, their application has been constrained by factors such as variable coordination numbers and low steric requirement.…”

Assembly of Six Types of Heteroleptic Pd2L4 Cages under Kinetic Control

“…Past efforts on the multicomponent coordination assembly have mainly applied thermodynamic approaches by designing building blocks to make a single heteroleptic assembly more significantly stable than the other possible assemblies. − As to the Pd 2 L 4 cage assembly composed of two Pd­(II) ions and four ditopic ligands (L), there are six types of heteroleptic cages (Figure ). Type I, − II, − and III , cages composed of two types of ditopic ligands have mainly been produced under thermodynamic control so far, and very recently type IV,…”