The syntheses, characterization, and emission properties of three tetragonal prismatic cages, 4a-4c, constructed from eight 90° Pt(II) acceptors, four linear dipyridyl ligands, and two tetraphenylethene (TPE)-based sodium benzoate ligands, are described. These cages are emissive in dilute solutions due to the metal-coordination-induced partial restriction of intramolecular rotation of their TPE units, while the dipyridyl moieties, which act as the pillars as well as the solvents, strongly influence these emissions. Specifically, cages 4a and 4b, bearing a 4,4'-dipyridine and a 1,2-di(4-pyridyl)ethylene as their pillar parts, respectively, display good emissions in common organic solvents at 485-493 nm that are derived from the TPE units. In contrast, cage 4c, with its BODIPY-based dipyridyl unit, exhibits two emission bands at 462-473 and 540-545 nm, originating from the TPE and BODIPY fluorophores, respectively. Moreover, cage 4b has been employed as a turn-on fluorescent sensor for thiol-containing amino acids via a self-destructive reaction, while the cage can also be regenerated via the addition of Pt(II) acceptors. The studies described herein not only enrich the ongoing research on fluorescent materials but also pave the way to prepare stimuli-responsive supramolecular coordination complexes.

Herein, we report the preparation of a multifunctional metallacage-core supramolecular gel by orthogonal metal coordination and host-guest interactions. A tetragonal prismatic cage with four appended 21-crown-7 (21C7) moieties in its pillar parts was first prepared via the metal-coordination-driven self-assembly of cis-Pt(PEt)(OTf), tetraphenylethene (TPE)-based sodium benzoate ligands and linear dipyridyl ligands. Further addition of a bisammonium linker to the cage delivered a supramolecular polymer network via the host-guest interactions between the 21C7 moieties and ammonium salts, which formed a supramolecular gel at relatively higher concentrations. Due to the incorporation of a TPE derivative as the fluorophore, the gel shows emission properties. Multiple stimuli responsiveness and good self-healing properties were also observed because of the dynamic metal coordination and host-guest interactions used to stabilize the whole network structure. Moreover, the storage and loss moduli of the gel are 10-fold those of the gel without the metallacage cores, indicating that the rigid metallacage plays a significant role in enhancing the stiffness of the gel. The studies described herein not only enrich the functionalization of fluorescent metallacages via elegant ligand design but also provide a way to prepare stimuli-responsive and self-healing supramolecular gels as robust and smart materials.

Control over the fluorescence of supramolecular assemblies is crucial for the development of chemosensors and light-emitting materials. Consequently, the postsynthetic modification of supramolecular structures via host-guest interactions has emerged as an efficient strategy in recent years that allows the facile tuning of the photophysical properties without requiring a tedious chemical synthesis. Herein, we used a phenanthrene-21-crown-7 (P21C7)-based 60° diplatinum(II) acceptor 8 in the construction of three exohedral P21C7 functionalized rhomboidal metallacycles 1-3 which display orange, cyan, and green emission colors, respectively. Although these colors originate from the dipyridyl precursors 10-12, containing triphenylamine-, tetraphenylethene-, and pyrene-based fluorophores, respectively, the metal-ligand coordination strongly influences their emission properties. The metallacycles were further linked into emissive supramolecular oligomers by the addition of a fluorescent bis-ammonium linker 4 that forms complementary host-guest interactions with the pendant P21C7 units. Notably, the final ensemble derived from a 1:1 mixture of 1 and 4 displays a concentration-dependent emission. At low concentration, i.e., <25 µM, it emits a blue color, whereas an orange emission was observed when the concentration exceeds >5 mM. Moreover, white-light emission was observed from the same sample at a concentration of 29 µM, representing a pathway to construct supramolecular assemblies with tunable fluorescence properties.

Y-serious acceptors and the multi-components strategy, the power conversion efficiencies (PCEs) of the single-junction OPVs have already reached 19%, [19,20] with the best fill factors (FFs) exceeding 80%. [21,22] However, the trade-off between the open-circuit voltage (V oc ) and the short-circuit current density (J sc ) still remains as a challenge to handle with in OPV devices. [23][24][25][26][27] Therefore, the synergistic improvement of V oc and J sc will be attractive for marching the efficiencies further for OPVs. [28][29][30] The charge transfer (CT) state cannot only affect the energy loss (E loss ) but also the generation efficiency of photo-induced carriers. [26] Narrowing the offset (ΔE LE-CT ) between the energy level of the CT state (E CT ) and the lowest excited state (E LE ) may reduce the probability of excitons quenching back to the ground state, which helps in mitigating E loss for a higher V oc . However, the diminished driving force is not in favor of exciton dissociation for a higher J sc , and vice versa. [29] The properties of CT states at the donor-acceptor (D-A) interfaces are supposed to be affected by the morphology Balancing and improving the open-circuit voltage (V oc ) and short-circuit current density (J sc ) synergistically has always been the critical point for organic photovoltaics (OPVs) to achieve high efficiencies. Here, this work adopts a ternary strategy to regulate the trade-off between V oc and J sc by combining the symmetric-asymmetric non-fullerene acceptors that differ at terminals and alkyl side chains to build the ternary OPV (TOPV). It is noticed that the reduced energy disorder and the enhanced luminescence efficiency of TOPV enable a mitigated energy loss and a higher V oc . Meanwhile, the third component, which is distributed at the host donor-acceptor interface, acts as the charge transport channel. The prolonged exciton lifetime, the boosted charge mobility, and the depressed charge recombination promote the TOPV to obtain an improved J sc . Finally, with synergistically improved V oc and J sc , the TOPV delivers an optimal efficiency of 19.26% (certified as 19.12%), representing one of the highest values reported so far.

Transfer request: A self‐assembled supramolecular charge‐transfer complex of 1‐(11‐oxo‐11‐pyren‐1‐ylmethoxy)undecyl)pyridinium bromide (PYR) and ethane‐1,2‐diyl bis(3,5‐dinitrobenzoate) (DNB) is shown to form vesicular aggregates in aqueous solution, in contrast to the tubular aggregates of pure PYR (see picture). A curvature‐dependent mechanism for this change is proposed.

This feature article summarized the recent progress on the construction of metallacycle/metallacage-cored supramolecular polymers by the hierarchical self-assembly, and the potential applications in the areas of light emitting, sensing, bio-imaging, delivery and release, etc., are also presented.

1,7-Dihalogenated boron dipyrromethene dyes were successfully synthesized and substituted, thus providing an entry to the final, elusive reactivity pattern. The spectroscopic properties of 1,7-disubstituted BODIPY dyes were studied and are discussed as a function of their structure.

Here, we present a method for the building of new bicyclic heterometallic cross-linked supramolecular polymers by hierarchical unification of three types of orthogonal noncovalent interactions, including platinum(II)−pyridine coordination-driven self-assembly, zinc−terpyridine complex, and host−guest interactions. The platinum−pyridine coordination provides the primary driving force to form discrete rhomboidal metallacycles. The assembly does not interfere with the zinc−terpyridine complexes, which link the discrete metallacycles into linear supramolecular polymers, and the conjugation length is extended upon the formation of the zinc−terpyridine complexes, which red-shifts the absorption and emission spectra. Finally, host−guest interactions via bis-ammonium salt binding to the benzo-21-crown-7 (B21C7) groups on the platinum acceptors afford the cross-linked supramolecular polymers. By continuous increase of the concentration of the supramolecular polymer to a relatively high level, supramolecular polymer gel is obtained, which exhibits self-healing properties and reversible gel−sol transitions stimulated by various external stimuli, including temperature, K + , and cyclen. Moreover, the photophysical properties of the supramolecular polymers could be effectively tuned by varying the substituents of the precursor ligands.