Luminescent copper(I)-based compounds have recently attracted significant attention due to their ability to achieve high emission quantum yields. Notably, Cu(I) clusters can also exhibit luminescence, and extending from small molecules to larger architectures represents a promising route toward novel materials through programmed self-assembly of molecular units. However, constructing supramolecular systems with Cu(I) remains challenging due to the metal center’s coordinative diversity. In this study, we demonstrate that this very diversity can be harnessed to design responsive systems. Specifically, we investigated the changes in the emissive profile of aggregates formed in water by phosphine-thioether copper(I) derivatives. Our results reveal that the self-assembly and disassembly of copper(I)-based coordination polymer nanoparticles (CPNs) are highly sensitive to solvent composition. These solvent-induced transitions are linked to modifications in the copper coordination sphere at the molecular level, which simultaneously alter both the emission characteristics and the morphology of the resulting aggregates. We anticipate that these findings will inspire the development of smart supramolecular systems based on dynamic coordinative metal centers, particularly for applications requiring environmental responsiveness.
Copper(I)-based luminescent materials are among the most promising candidates for solid-state lighting, sensing, and biomedical diagnostics due to their strong emission and low cost compared to rare metals such as Ir, Pt, Ru, or lanthanides. Despite this advantage, the limited photoluminescence quantum yield of Cu(I) compounds in fluid environments remains a major barrier for their use in biological and environmental applications.Neuropilin-1 Antibody Protocol The luminescence mechanism typically involves room temperature phosphorescence or thermally activated delayed fluorescence (TADF), both of which depend heavily on the nature of the ligands coordinated to the metal center. Moreover, aggregation-induced emission (AIE) has been observed in Cu(I) systems, particularly when short Cu···Cu contacts form in aggregated states, leading to nonconventional AIE based on metal-metal interactions. This behavior is especially pronounced in halogen-containing complexes—iodine, for example, acts as a versatile bridging ligand enabling the formation of well-known L4Cu4I4 cubane-like clusters. At room temperature, these clusters display cluster-centered (3CC) phosphorescence arising from iodine-to-metal charge transfer (3XMCT) and metal-centered (3MC: d10 → d9s1 Cu) transitions. The emission energy is directly influenced by Cu···Cu distances within the cluster, with shorter distances causing redshifts under pressure. When conjugated ligands are present, metal-to-ligand charge transfer (MLCT) contributions become detectable, enhancing photoluminescence efficiency while suppressing the fast non-radiative decay of the 3CC state. TADF has also been identified as an effective strategy to boost emission performance in Cu(I) complexes.
However, the luminescence of these clusters is often lost in solution due to the dynamic nature of Cu–I and Cu–L bonds, which lead to structural disassembly in polar solvents. Even in the solid state, different conformers show substantial variations in their emissive properties. This inherent coordinative flexibility poses challenges for constructing stable supramolecular structures but opens opportunities for stimuli-responsive behaviors.CBX4 Antibody Formula Additionally, Cu(I) is prone to oxidation to Cu(II) in the presence of moisture or air unless fully stabilized, limiting its application in aqueous environments.PMID:34057027 To address these issues, we designed a family of hybrid phenylthioether-diphenylphosphine ligands capable of stabilizing Cu(I) and promoting extended supramolecular organization. Reaction of these ligands with CuI yielded coordination polymers [Cu4I4(L)2]n with a cubane-like structure, confirmed by single-crystal X-ray diffraction and far-IR spectroscopy. All compounds exhibited strong yellow emission at room temperature in the solid state, transitioning to dual emission at 77 K. Surprisingly, we observed evidence suggesting TADF rather than phosphorescence as the dominant emission pathway at ambient conditions. Most notably, these systems self-assemble into CPNs in aqueous media—a rare example of Cu(I)-based CPNs. Furthermore, we monitored the dynamic depolymerization process of these nanoparticles upon changing solvent composition, revealing their responsiveness to environmental cues. Such sensitivity underscores the importance of media design alongside molecular design in creating functional self-assembled systems. The feasibility of processing these materials in water highlights their potential for biocompatible and environmentally relevant applications. Overall, our work paves the way for new strategies in fabricating luminescent, stimuli-responsive, and water-compatible nanomaterials based on copper(I) and other coordinatively dynamic metal centers.MedChemExpress (MCE) offers a wide range of high-quality research chemicals and biochemicals (novel life-science reagents, reference compounds and natural compounds) for scientific use. We have professionally experienced and friendly staff to meet your needs. We are a competent and trustworthy partner for your research and scientific projects.Related websites: https://www.medchemexpress.com