Construction of 1,3,5-Triazine-Based Prisms and Their Enhanced Solid-State Emissions

In this study, two trigonal prisms based on the 1,3,5-triazine motif (SA and SB), distinguished by hydrophobic groups, were prepared by the self-assembly of tritopic terpyridine ligands and Zn(II) ions. SA and SB exhibited high luminescence efficiencies in the solid state, overcoming the fluorescence quenching of the 1,3,5-triazine group caused by π–π interactions. Notably, SA and SB exhibited different luminescence behaviors in the solution state and aggregation state. SB with 12 alkyl chains exhibited extremely weak fluorescence in a dilute solution, but its fluorescence intensity and photoluminescence quantum yield (PLQY) were significantly enhanced in the aggregated state (with the increase in the water fraction), especially in the solid state. Different from the gradually enhanced efficiency of SB, the PLQY of SA gradually decreased with the increase in aggregation but still maintained a high luminescence efficiency. These two complexes exhibited different modes to solve the fluorescence quenching of 1,3,5-triazine in the solid state. The hierarchical self-assembly of SB exhibited nanorods owing to the hydrophobic interactions of alky chains, while SA aggregated into spheres under the influence of π–π interactions

Discrete Platinum(II) Metallacycles with Inner- and Outer-Modified 9,10-Distyrylanthracene: Design, Self-Assembly, and Luminescence Properties

To completely unravel the relationship between structures and luminescence properties of inner- and outer-modified metallacycles, two rhombic metallacycles S1 and S2 with 9,10-distyrylanthracene (DSA) were constructed herein via the design of DSA moieties on the inside or outside of metallacycles. Similar building blocks of the two metallacycles led to the same emission wavelengths in a dilute solution. In contrast, their fluorescence emissions in the aggregation and solid states were significantly different and revealed interesting emission behaviors from structures with inner- and outer-modified design. Finally, based on their luminescence properties, a tunable solid-state fluorescence emissive material was easily obtained by the mixing of two supramolecules in different ratios. This unique design suggested that the modified position of fluorophores exerts a key impact on the adjustment of luminescence from a dilute solution to the aggregated state and will be of great significance for the development of luminescent materials based on supramolecules

Metal–Organic Dimerization of Dissymmetrical Ligands toward Customized Through-Space Chromophore Interactions

The pursue of good photophysical properties for organic optoelectronic materials requires a well understanding of through-space chromophore interactions, which further requires a well control over the spatial arrangement of chromophores. However, it remains a challenge to precisely customize the positioning of chromophores in their aggregating form such as in a simplest cofacially stacked dimer. Herein, this work provides a customizable molecular design based on dissymmetrical ligands that can enable a precise control over chromophore interactions through the formation of metal–organic dimers. Anti-paralleled stacking of two dissymmetrical ligands in the metal–organic dimers results in a lateral shifting of chromophore stacking, whose spacing is determined and adjusted by the degree of ligand dissymmetry. Three metal–organic dimers with a variation in chromophore spacing exhibited unique photophysical properties in both solution and solid states and displayed high-efficient luminescence against quenching in their aggregating states. This strategy thereby offers a universally applicable way to construct chromophore dimers with fixed cofacial spacing and determinate through-space interactions

Metal–Organic Dimerization of Dissymmetrical Ligands toward Customized Through-Space Chromophore Interactions

The pursue of good photophysical properties for organic optoelectronic materials requires a well understanding of through-space chromophore interactions, which further requires a well control over the spatial arrangement of chromophores. However, it remains a challenge to precisely customize the positioning of chromophores in their aggregating form such as in a simplest cofacially stacked dimer. Herein, this work provides a customizable molecular design based on dissymmetrical ligands that can enable a precise control over chromophore interactions through the formation of metal–organic dimers. Anti-paralleled stacking of two dissymmetrical ligands in the metal–organic dimers results in a lateral shifting of chromophore stacking, whose spacing is determined and adjusted by the degree of ligand dissymmetry. Three metal–organic dimers with a variation in chromophore spacing exhibited unique photophysical properties in both solution and solid states and displayed high-efficient luminescence against quenching in their aggregating states. This strategy thereby offers a universally applicable way to construct chromophore dimers with fixed cofacial spacing and determinate through-space interactions

Coordination-Induced Conformational Control Enables Highly Luminescent Metallo-Cages

In recent years, luminescent materials have received a great deal of attention due to their wide range of applications. However, exploring a simple solution to overcome the fluorescence quenching resulting from the aggregation of conventional organic fluorophores remains a valuable area of investigation. In this study, we successfully constructed two metallo-cages, namely, SA and SB, through coordination-driven self-assemblies of the triphenylamine (TPA)-based donor L with different diplatinum(II) acceptors LA and LB, respectively. These metallo-cages take advantage of their steric nature and curved conformation to more effectively limit the free rotation of the benzene ring and hinder π–π stacking in the solid state, which successfully inhibited fluorescence quenching and realizing highly efficient luminescent properties. Therefore, this work offers a new design strategy for preparing materials with excellent luminescent properties

Metal–Organic Dimerization of Dissymmetrical Ligands toward Customized Through-Space Chromophore Interactions

The pursue of good photophysical properties for organic optoelectronic materials requires a well understanding of through-space chromophore interactions, which further requires a well control over the spatial arrangement of chromophores. However, it remains a challenge to precisely customize the positioning of chromophores in their aggregating form such as in a simplest cofacially stacked dimer. Herein, this work provides a customizable molecular design based on dissymmetrical ligands that can enable a precise control over chromophore interactions through the formation of metal–organic dimers. Anti-paralleled stacking of two dissymmetrical ligands in the metal–organic dimers results in a lateral shifting of chromophore stacking, whose spacing is determined and adjusted by the degree of ligand dissymmetry. Three metal–organic dimers with a variation in chromophore spacing exhibited unique photophysical properties in both solution and solid states and displayed high-efficient luminescence against quenching in their aggregating states. This strategy thereby offers a universally applicable way to construct chromophore dimers with fixed cofacial spacing and determinate through-space interactions

Metal–Organic Dimerization of Dissymmetrical Ligands toward Customized Through-Space Chromophore Interactions

The pursue of good photophysical properties for organic optoelectronic materials requires a well understanding of through-space chromophore interactions, which further requires a well control over the spatial arrangement of chromophores. However, it remains a challenge to precisely customize the positioning of chromophores in their aggregating form such as in a simplest cofacially stacked dimer. Herein, this work provides a customizable molecular design based on dissymmetrical ligands that can enable a precise control over chromophore interactions through the formation of metal–organic dimers. Anti-paralleled stacking of two dissymmetrical ligands in the metal–organic dimers results in a lateral shifting of chromophore stacking, whose spacing is determined and adjusted by the degree of ligand dissymmetry. Three metal–organic dimers with a variation in chromophore spacing exhibited unique photophysical properties in both solution and solid states and displayed high-efficient luminescence against quenching in their aggregating states. This strategy thereby offers a universally applicable way to construct chromophore dimers with fixed cofacial spacing and determinate through-space interactions

A Highly Luminescent Metallo-Supramolecular Radical Cage

Luminescent metal-radicals have recently received increasing attention due to their unique properties and promising applications in materials science. However, the luminescence of metal-radicals tends to be quenched after formation of metallo-complexes. It is challenging to construct metal-radicals with highly luminescent properties. Herein, we report a highly luminescent metallo-supramolecular radical cage (LMRC) constructed by the assembly of a tritopic terpyridinyl ligand RL with tris(2,4,6-trichlorophenyl)methyl (TTM) radical and Zn2+. Electrospray ionization-mass spectrometry (ESI-MS), traveling-wave ion mobility-mass spectrometry (TWIM-MS), X-ray crystallography, electron paramagnetic resonance (EPR) spectroscopy, and superconducting quantum interference device (SQUID) confirm the formation of a prism-like supramolecular radical cage. LMRC exhibits a remarkable photoluminescence quantum yield (PLQY) of 65%, which is 5 times that of RL; meanwhile, LMRC also shows high photostability. Notably, significant magnetoluminescence can be observed for the high-concentration LMRC (15 wt % doped in PMMA film); however, the magnetoluminescence of 0.1 wt % doped LMRC film vanishes, revealing negligible spin-spin interactions between two radical centers in LMRC