Muxin Yu

Employing the epimeric ligands, cinchonidine (L1) and cinchonine (L2), two chiral Cu(I) coordination polymers were synthesized: a 1D chain Cu4I4(L1) and a 3D framework Cu4I4(L2). Structural analyses reveal that Cu4I4(L1) incorporates interconnected distorted gyroscope-like and cubane-type Cu4I4 clusters, whereas Cu4I4(L2) comprises solely cubane-type Cu4I4 clusters. This architectural divergence could be attributed to the distinct spatial preferences of the two N-donor atoms in the epimeric ligands. Photoluminescence studies show that Cu4I4(L1) emits orange light with a single broad band (λem = 614 nm, ΦPL = 21.03%), while Cu4I4(L2) displays yellow emission consisting of multiple bands (λem = 575 nm, ΦPL = 1.32%). DFT calculations correlate these differences to the variations in frontier orbital distributions and electronic transition pathways. Notably, the two compounds exhibit distinct circularly polarized luminescence with maximum glum values of +6.1 × 10–3 for Cu4I4(L1) and –2.4 × 10–3 for Cu4I4(L2). This work illustrates how subtle stereochemical differences in epimeric ligands direct the structural self-assembly of chiral Cu(I)-cluster-based coordination polymers, thereby tuning their photophysical and chiroptical properties, and provides a valuable guideline for designing CPL-active Cu(I)-cluster-based materials.

Lead-based halide perovskite nanocrystals (PNCs) have emerged as a leading class of materials for optoelectronic applications due to their outstanding optical properties. However, their practical deployment is hindered by concerns regarding lead toxicity. To address this issue, researchers have explored low-toxicity metals as lead substitutes, enabling the development of novel lead-free PNCS. In this work, through targeted compositional engineering of the glass matrix, we simultaneously realize Cs2MnBr4 PNCs-embedded glass and Tm3+:NaYbF4/Cs2MnBr4 dual-phase glass. The introduction of SnO, YbF3, and MnBr2, markedly enhances the 526 nm green emission of Cs2MnBr4 PNCs by simultaneously suppressing Mn2+ oxidation, promoting nucleation, and facilitating crystal growth. Simultaneously, efficient upconversion luminescence (UCL) was observed upon 980 nm near-infrared (NIR) excitation, attributed to the successful doping of Tm3+ into the low-phonon-energy NaYbF4 nanocrytals. The prepared dual-phase glass supports dual-mode optical encoding: green emission from Cs2MnBr4 under UV light and blue UCL from Tm3+:NaYbF4 under 980 nm excitation, enabling advanced anti-counterfeiting.

Materials exhibiting aggregation-induced emission (AIE) behaviour enable strong emission in solid state and can respond to various external stimuli, which may facilitate the development of materials for optical sensing, bioimaging or optoelectronic devices. Herein, we use an AIE luminogen 2’,5’-diphenyl-[1,1’:4’,1”-terphenyl]-4,4”-dicarboxylic acid as the ligand to prepare an AIEgen-based MOF (metal-organic framework) named FJI-H31. FJI-H31 exhibits bright luminescence under ambient conditions (under air and at room temperature), but almost no emission is observed under vacuum. Our investigation shows that the emission intensity displays a smooth and reversible enhancement with increased gas pressure, which may be attributed to the restriction of intramolecular motion brought by structural deformation under pressure stimulus. Unlike most pressure-responsive MOFs, the luminescence reverts to its original state once gas pressure recovers. By virtue of its unique optical properties, a luminescent MOF with sensing ability of gas-pressure is realized.

Achieving white‐light emission, especially white circularly polarized luminescence (CPL) from a single‐phase material is challenging. Herein, a pair of chiral Cu^I coordination polymers (1‐M and 1‐P) have been prepared by the asymmetrical assembly of achiral ligands and Cu₂I₂ clusters. The compounds display dual emission bands and can be used as single‐phase white‐light phosphors, achieving a “warm”‐white‐light‐emitting diode with an ultra‐high color rendering index (CRI) of 93.4 and an appropriate correlated color temperature (CCT) of 3632 K. Meanwhile, corresponding CPL signals with maximum dissymmetry factor |g_lum|=8×10⁻³ have been observed. Hence, intrinsic white‐light emission and CPL have been realized simultaneously in coordination polymers for the first time. This work gains insight into the nature of chiral assembly from achiral units and offers a prospect for the development of single‐phase white‐CPL materials.

Achieving white‐light emission, especially white circularly polarized luminescence (CPL) from a single‐phase material is challenging. Herein, a pair of chiral Cu^I coordination polymers (1‐M and 1‐P) have been prepared by the asymmetrical assembly of achiral ligands and Cu₂I₂ clusters. The compounds display dual emission bands and can be used as single‐phase white‐light phosphors, achieving a “warm”‐white‐light‐emitting diode with an ultra‐high color rendering index (CRI) of 93.4 and an appropriate correlated color temperature (CCT) of 3632 K. Meanwhile, corresponding CPL signals with maximum dissymmetry factor |g_lum|=8×10⁻³ have been observed. Hence, intrinsic white‐light emission and CPL have been realized simultaneously in coordination polymers for the first time. This work gains insight into the nature of chiral assembly from achiral units and offers a prospect for the development of single‐phase white‐CPL materials.

Four lanthanide metal-organic frameworks (Ln-MOFs), namely {[Me₂NH₂][LnL]·2H₂O}_n (Ln = Eu 1, Tb 2, Dy 3, Gd 4), have been constructed from a new tetradentate ligand 1-(3,5-dicarboxylatobenzyl)-3,5-pyrazole dicarboxylic acid (H₄L). These isostructural Ln-MOFs, crystallizing in the monoclinic P2₁/c space group, feature a 3D structure with 7.5 Å × 9.8 Å channels along the b axis and the point symbol of {4¹⁰.6¹⁴.8⁴} {4⁵.6}₂. The framework shows high air and hydrolytic stability, which can keep stable after exposed to humid air for 30 days or immersed in water for seven days. Four MOFs with different lanthanide ions (Eu³⁺, Tb³⁺, Dy³⁺, and Gd³⁺) ions exhibit red, green, yellow, and blue emissions, respectively. The Tb-MOF emitting bright green luminescence can selectively and rapidly (3+ in aqueous media via a fluorescence quenching effect. The detection shows excellent anti-inference ability toward many other cations and can be easily recognized by naked eyes. In addition, it can also be utilized as a rapid fluorescent sensor to detect acetone solvent as well as acetone vapor. Similar results of sensing experiments were observed from Eu-MOF. The sensing mechanism are further discussed.

A flexible two‐fold interpenetrated indium metal‐organic framework InOF‐23, featuring one‐dimensional micro‐sized channels decorated by exposed N groups, was successfully synthesized. Interestingly, InOF‐23 displays unique dynamic responses to different gases (N₂, Ar, and CO₂) at low and room temperatures, which indicates that it can be a good candidate for gas adsorption and separation. Furthermore, the high efficiency detection for p‐nitroaniline (pNA) makes InOF‐23 a potential chemosensor for nitroaromatic explosives.