Assembly of Ruthenium-Based Complex into Metal–Organic Framework with Tunable Area-Selected Luminescence and Enhanced Photon-to-Electron Conversion Efficiency

Abstract

Host–guest photofunctional materials have received much attention recently due to their potential applications in light emitting diodes, polarized emission, and other optoelectronic fields. In this work, we report the encapsulation of a photoactive ruthenium-based complex (4,4′-diphosphonate-2,2′-bipyridine) into the biphenyl-based metal–organic framework (MOF) as a host–guest material toward potential photofunctional applications. The resulting material (denoted as Ru@MOF) presents different two-color blue/red luminescences at the crystal interior and exterior as detected by three-dimensional confocal fluorescence microscopy. Additionally, up-conversion emission and an enhanced photoluminescence lifetime relative to the pristine Ru-based complex can also be observed in this Ru@MOF system. Upon attaching on the rutile TiO2 nanoarray, the Ru@MOF also exhibits alternated photoelectrochemical properties relative to the pristine complex. Moreover, a density functional theoretical calculation was performed on the Ru@MOF structure to provide understanding of the host–guest interactions. Based on the combination of experimental and theoretical studies on the Ru@MOF system, the aim of this work is to deeply investigate how the host–guest materials can present different photofunctionalities and optoelectronic properties compared with those of the individual components, and to give detailed information on the potential host–guest energy/electronic transfer between the MOF and the complex.

Concentration Dependent Dimensionality of Resonance Energy Transfer in a Postsynthetically Doped Morphologically Homologous Analogue of UiO-67 MOF with a Ruthenium(II) Polypyridyl Complex

“…61 It was observed that, at lower concentrations, the RuDPBPY doping is inhomogeneous throughout the crystal systemrestricted to the outermost layers of the crystal. At higher RuDPBPY concentrations, however, the RuDPBPY dopant penetrates further into the crystal populating more of the interior reaching a saturating concentration limit where the crystal is nearly uniformly doped.…”

Binuclear Bi(iii) halide complexes with 4,4′-ethylenepyridinium cations: luminescence tuning by reversible solvation

“…Anyway, additional studies in this field, allowing the collection of extended statistics, are required. Solvatochromism is a well-known phenomenon, appearing in diverse classes of compounds, in particular, in metal-organic frameworks [32][33][34] and various aromatic substrates. 35 Discovery of this effect in the post-transition metal halides provides the opportunities of their further use in development of new materials.…”

Epitaxial Growth of Hetero‐Ln‐MOF Hierarchical Single Crystals for Domain‐ and Orientation‐Controlled Multicolor Luminescence 3D Coding Capability

“…Zuschriften these hierarchical crystals.F or crystals 4-15, the domain segregation cannot be directly observed by eyes,b ut under fluorescence microscope by UV radiation at 350 nm, the hierarchical crystals show clearly segregated multicolor luminescence,which can be applied for domain-and orientation-controlled multicolor or white-light emitting modulation as discussed below. [26,27] Forc omparison, solid-solution type hetero-Ln-MOF crystals 16-18 obtained by mixing-Ln isomorphous growth lead to uniform emissive colors without domain differentiation. Figure 3illustrates the applicable models of domain-and orientation-controlled emissions with the hierarchical hetero-Ln-MOF single crystals.The local and spatial luminescence is studied by am icro-Raman spectrometer.Ina ccordance with the epitaxial growing models with either core-shell or striped structural features mentioned before,t wo kinds of emitting models are proposed in Figure 3a.F or the core-shell model, by rotating the crystal to different positions and orientations, multicolor to white-light emissions can be read out, while for the striped model, asimilar goal can be achieved by rotating or moving the bar-like crystals to different positions and orientations.S pecifically,t aking the Eu@Tb-MOF bimetallic hierarchical crystal as an example (Figure 3b), when the crystal is positioned for UV radiation on the outer Tb-domain (site 1), green light emission with maximum at 545 nm is produced, showing aC IE coordinate at (0.375, 0.594); radiation on the central Eu-domain (site 3) results in red light emission with maximum at 618 nm and CIE coordinate at (0.641, 0.348), while yellow light is observed from the connecting zone (site 2) with both emission peaks at 545 and 618 nm, showing aCIE coordinate at (0.549, 0.436).…”