In this review, we describe recent advances in the development of fluorescence-based viscosity sensors, termed Molecular Rotors, and discuss how these dyes can be exploited to quantify the microviscosity of biological environment, probe lipid membranes and non-canonical nucleic acid architectures and track dynamic processes, including protein aggregation.

This review discusses the molecular design strategies, recognition mechanisms, and both in vitro and in vivo bio-applications (especially for diagnosis and therapy of tumors) of activatable dyes based on the dicyanomethylene-4H-pyran (DCM) scaffold.

This Minireview summarizes recent advances in sequence-defined synthetic polymers (SDPs), focusing on newly developed sequencing methods including tandem mass spectrometry (MS) based on bond-selective cleavage and biased ionization, and primary MS based on cascade degradation. Their biological functions are also highlighted, and future perspectives of SDPs outlined.

A variety of laboratory- and synchrotron-based chemical imaging techniques can be employed to study heterogeneous catalysts at high spatial and temporal resolutions. This review discusses related advances in the fields of olefin polymerization and polyolefin decomposition catalysis and highlights future research directions that can ultimately deliver more detailed insights into structure-performance relationships in relevant catalyst materials.

Is it possible that light can be formulated as capsules, injection solutions, and packed into polymers? Yes, if the light is generated from molecules. The concept of “molecular light” has the potential to significantly expand our perspectives on the potential applications of light.

This work reports a two-dimensional (2D) MXene membrane with super-aligned nanochannels by applying shear forces to liquid-crystalline (LC) MXene nanosheet dispersion. The as-prepared LC MXene membrane (LCMM) shows excellent in-plane stacking order and precise interlayer spacing of ≈6 Å, demonstrating ultrahigh selectivities toward Li⁺/Na⁺, Li⁺/K⁺, and Li⁺/Rb⁺ (≈45, ≈49, and ≈59, respectively), outperforming the state-of-the-art membranes.

Biologische Kabel als Elektroden: Elektrisch leitfähige filamentöse Kabelbakterienskelette wurden als freistehende biologische Elektroden verwendet und zeigen eine katalytische Selektivität für Sauerstoff. Die Skelette wandeln Wasser in Sauerstoff um, und umgekehrt, Sauerstoff zurück zu Wasser. Wir zeigen, dass diese Reaktionen entweder durch ein externes elektrisches Feld, oder durch einen einfachen Sauerstoffkonzentrationsgradienten angetrieben werden können.

19-nor-Geranylgeranyldiphosphat mit entfernter Methylgruppe wurde synthetisiert und mit 20 Diterpensynthasen in Diterpenanaloga umgewandelt. In einigen Fällen wurden nur die Desmethylderivate der natürlichen Enzymprodukte erhalten, bei einigen Enzymen wurde jedoch eine dramatische Veränderung der Reaktivität beobachtet. Die neu eröffneten Reaktionswege zu Verbindungen mit unbekannten Grundgerüsten offenbaren einen faszinierenden Methylgruppeneffekt in der Diterpenbiosynthese.

A novel asymmetric solvents regulated crystallization limitation strategy is developed to lower electrolyte operation temperature windows for lithium metal batteries. Mixing asymmetric ethylene sulfite (ES) and fluoroethylene carbonate (FEC) can reduce the molecular interaction and orientation arrangement dynamics, allowing the resulting electrolyte to show fast ion transport even at −50 °C.

Embedded nano-sized enzymes, in the presence of their respective substrates, can drive centimeter-scale polymer sheets along directed linear paths and rotational trajectories on the air/water interface.

Free energy barriers of acid-catalyzed cracking and isomerization reactions of alkenes are computed at an unprecedented level of theory, combining dynamic effects investigated by ab initio molecular dynamics and high-level electronic energy calculations with Machine Learning thermodynamic Perturbation Theory. The results are close to chemical accuracy.

We develop a novel hydrophobic building block, 4a-azonia-naphthalene (AN), for n-type organic mixed ionic-electronic conductors. AN have the strong electron-withdrawing ability, and exhibit strong cation-π interactions, leading to smaller π–π stacking distance, interesting ion diffusion behavior, and good morphology stability, resulting in improved ion diffusion/injection speed and operational stability of organic electrochemical transistors.

A Magnetic Resonance Imaging-Chemical Exchange Saturation Transfer (MRI-CEST) method to image and quantify in vivo water cycling across cell membranes is reported. Parametric MRI-maps can be obtained that report, for each voxel, the degree of water permeability across cells. Cell membrane water permeability is a biomarker of cancer aggressiveness and can be used to monitor chemotherapy, as demonstrated in murine models of breast cancers.

For AuZn/ZnO nanoarrays, a bimetallic synergistic effect reduces the activation energy barrier of CO₂ molecules and accelerates electron transfer. The dual metal active sites effectively electrocatalyze CO₂ and H₂O conversion to syngas with a tunable syngas CO/H₂ ratios from 0.25 to 2.50.

The plant Schisandra macrocarpa was explored for the extraction of novel compounds from its fungal endophyte Penicillium sp. DG23. Of the indole diterpenoids and derivatives identified, biological evaluation highlighted schipenindolene A as a potent HMGCR degrader that further lowered cholesterol with statin (HMGCR inhibitor) by activating the endoplasmic reticulum-associated degradation pathway and inhibiting the compensatory effects of statin.

Novel post-synthetic ensembling design comprising methodical incision of conventional FAU-type zeolites into unit-cell level zeolitic fragments and their subsequent reorganization into hierarchically ordered zeolites exhibiting 2D-hexagonal/3D-cubic mesopore channels. This approach eludes the kinetic constraints of conventional crystallization to produce hierarchical zeolites having excellent catalytic properties in hydrocracking applications.

The Werner salt [Ni(NH₃)₆]Cl₂ can be used as both a nitrogen and a catalytic nickel source that allow for the efficient amination of aryl chlorides in the presence of a catalytic amount of bipyridine ligand under the irradiation of 390–395 nm light without the need of any additional catalysts, solving the problem of easy deactivation and difficult recovery of transition metal nickel catalysts.

A joint theoretical and experimental study on 32 endohedral silafulleranes is presented. Template effects of Cl⁻ are investigated for the [X@Si₂₀Y₂₀]⁻ complexes that are classified as “confined Lewis pairs”. The origins of the diagnostic ³⁵Cl NMR chemical shifts are elucidated computationally. Finally, we disclose the synthesis of [PPN][Cl@Si₂₀Y₂₀] (Y=Me, Et, Br) including their thorough characterization.

T-shaped polyphiles self-assemble into a liquid quasicrystal and a series of liquid-crystalline periodic approximants, all representing polygonal honeycombs formed by the stacking of p-terphenyls. Featuring giant octagonal motifs containing non-regular trapezoidal or pentagonal with regular triangular and square tiles, the phases assume a transition of motif orientation, triggered by the changing conformation and entropy of the alkyl end chains.

Cyclic thiosulfinates can generate disulfide-crosslinked dynamic covalent hydrogels without additional stimuli to gain control over stress relaxation based on thiol content and mode of crosslinker application. Pluripotent stem cell-derived cardiomyocytes can be 3D cultured in hydrogels containing macromonomers with this chemistry, displaying native behaviours, such as cell spreading and spontaneous beating.

Herein, we demonstrate the cobalt-catalyzed asymmetric desymmetrization of phosphinamides with haloalkynes with excellent enantioinduction and inverse regioselectivity. In a single step, the approach provides access to several P-chiral molecules. Based on control experiments and preliminary study, a plausible mechanism is provided.

Polyoxometalate nanozyme-integrated polydopamine-conjugated nanomotors (POMotors) were constructed. They show peroxidase-like catalytic activity and NIR-triggered photothermal properties, therefore exhibiting enzyme-powered enhanced Brownian motion and NIR-triggered self-propulsion. Based on these properties of POMotors, a highly efficient self-propulsion-enhanced photothermal-catalytic synergistic tumor therapy was achieved.

Microwave-assisted PCN-222 nanocrystals has been successfully used as nanoreactors to promote the nucleation and growth of hydrogen clathrates. This research shows that hydrogen can be enclathrated at lower pressure than the bulk system, with fast kinetics and with a nearly complete water-to-hydrate conversion.

A chemoenzymatic method based on sortase A catalyzed ligation was developed to characterize proteoforms with N-terminal glycine in human cells and quantify their dynamics. Around 2000 proteoforms with N-terminal glycine were identified, and most of them were previously unknown. Bioinformatic analyses reveal proteoforms with N-terminal glycine with the fastest and slowest degradation rates have different functions and localizations.

The transient carbonation of polyols under a CO₂ atmosphere enables their C−H monoalkylation by photoredox catalysis. This reactivity results from an unprecedented C−H activation through intramolecular hydrogen bonding.

A metal-free helical covalent inorganic polymer (CityU-10) has been successfully prepared. Its crystal structure shows that the same-handed helical chains form a pseudo-two-dimensional layer via multiple hydrogen-bonding interactions. Then, the left-handed layers and right-handed layers alternatively stack together to form a three-dimensional supramolecular structure.

In batteries, the formation of gases such as oxygen, carbon dioxide and ethylene accompanies degradation. Ultrasensitive on chip electrochemistry mass spectrometry reveals previously undetectable gas evolution in lithium ion batteries. The ensuing insight will enable battery scientists to predict degradation mechanisms and discover new strategies to stabilise device performance.

The counterion makes a difference in alkene hydrogenations promoted by low-valence cobaltate salts. The best performing catalyst cleanly hydrogenated various alkenes (including tri- and tetra-substituted) under mild conditions. Mechanistic studies point toward a homotopic catalyst and show how counterion coordination to hydride intermediates modulates the barrier for the turnover-limiting migratory insertion.

We developed four small-molecule acceptors (Qo1, Qo2, Qo3 and Qo4) by incorporating a methylation strategy. Solar cells fabricated with polymer donor PM6 and Qo2 realized the highest power conversion efficiency of 18.4 %, surpassing the efficiencies of devices based on Qo1 (15.8 %), Qo3 (16.7 %), and Qo4 (2.4 %).

Fluorescence-spectroelectrochemical anion sensing is introduced as a powerful method to enable anion detection via simultaneous emission and voltammetry readouts. The combined advantages of both approaches facilitate anion sensing at very low sensor concentrations and in a competitive solvent system using a redox-active ferrocene-containing BODIPY anion receptor, wherein photoinduced electron transfer (PET) modulates fluorescence emission.

The ammonolysis of glyoxal with dimethylamine occurs at the air-water nanodroplet interface with the stepwise pathways facilitated by the water dimers, which is highly feasible and plays a pivotal role in removing glyoxal.

The full potential of the chiral self-sorting in gold(I)-sulfido cluster system has been explored for the first time. Different combinations of axial chiral ligands give rise to distinct chiral gold(I)-sulfido clusters through different types of chiral self-assembly and self-sorting processes, evolving from homochiral assembly to heterochiral self-sorting and the unprecedented heterochiral and heteroleptic self-sorting.

The intersection of surfactant partitioning, spontaneous emulsification, and substrate wettability generates a unique type of motion—droplet oscillation—rarely reported in the literature for oil-in-water emulsion systems. The effect of varying the concentration of the surfactant, substrate properties, and the chemical nature of the oil and surfactant on the oscillating droplets was studied.

The oxygen vacancy dilute the resistance of built-in electric field of Ru/NiMoO_4-x to accelerate the hydrogen transfer step in hydrogen spillover, improving hydrogen evolution reaction performance in alkaline seawater.

A Bi₁₂O₁₇Cl₂ piezo-catalyst was prepared with peculiar [Bi₃O_4.25] layers. The existence of [Bi₃O_4.25] not only serves as active sites but also satisfies energy band structure for 2e⁻ ORR and 2e⁻ WOR, realizing the dual pathway for adequate H₂O₂ synthesis. Expectedly, the constructed Bi₁₂O₁₇Cl₂-PESF emerges superior degradation activity for pollutants attributed to sufficient use of in situ produced H₂O₂ to abundant ⋅OH.

A new look at catalytic Wittig-type olefinations. We explored the use of transition metal catalysis to form ylide equivalents from readily available starting materials leading to the development of a highly E-selective copper-catalyzed olefination of imines with alkenyl boronate esters as coupling partners.

Online monitoring of formose reaction by ion-mobility-separation mass-spectrometry reveals the growth of the size and complexity of sugar molecules. Chemometrics analysis identified the key reaction mixture components and their contribution to the dynamic reaction changes. The results allowed the reconstruction of the reaction networks and analysis of the kinetics of early steps of formose reaction.

A versatile chiral amide directing group has been studied in the context of the ruthenium(II)-catalyzed asymmetric C−H activation. Six transformations have been achieved, affording a series of valuable chiral products. With this tool, concise syntheses of many natural products and biologically active compounds (e.g., Montroumarin, Cyclosporone E, Cyclosporone Q, Concentricolide, Chuangxinol, and Eleutherol) were accomplished.

The superior crosslinked products derived from HFE decomposition via nucleophilic O species attack serve as valuable sutures. They prevent fragmented substances from escaping CEI construction, providing an excellent foundation for the homogeneous deposition of LiF related species. Consequently, an effective CEI with both rigidity and flexibility is established, which reduces cell polarization, achieves long-lasting electrochemical performance.

Catechol-isolated mesoporous single iron atomic nanocatalysts (mSAFe NCs) with ligand-field-effect-promoted cocatalytic Fenton catalysis have been constructed. The catechols from dopamine serve as both an iron coordination site for atomic isolation and a reductive ligand to generate a field-effect-based cocatalytic system that instantly reduces Fe^III species to Fe^II species within the mSAFe NCs, thereby promoting in vivo Fenton catalytic effects against tumors.

Pathway-dependent supramolecular assemblies from a rationally designed glutamide derivative were found, which formed distinct chiral nanotwist and nanotube depending on the cooling rate. Pathway-dependent self-assembly showed also the ability to control over the guest molecules with emergent blue or green circularly polarized luminescence and topochemical polymerization.

The high-spin state of Fe in Fe₅Ni₄S₈ promotes the accumulation of surface OH⁻ and accelerates the rate of electron transfer, thereby establishing a correlation with the kinetic rate of the reconstructive reaction.

White phosphorus (P₄) can be selectively activated and functionalized via low-valent cobalt complexes. Subsequent treatment of the acylated P₄ ligands with cyanide induces a rare [3+1] fragmentation and yields cyanophosphanides (P₁) and triphosphido cobaltate (P₃). Additional experiments with neutral cyanide or isocyanide provide insight into a plausible fragmentation mechanism and allow the isolation of potential intermediates.

A hydrated [3+2] cyclotelomerization of butafulvenes has been developed to create spiro fused tricyclic rings with a contiguous fully substituted carbon motif.

An electrolyte with weak solvation effect is rationally developed for aqueous Zn ion batteries (AZIBs). Benefiting from the reduced solvated H₂O, boosted desolvation kinetics and in situ formed solid electrolyte interface (SEI) layer, Zn anode cycled in this electrolyte can deliver enhanced cycling stability.

The singlet-triplet energy gap was modulated by controlling the inter-cluster interaction defined by the supramolecular arrangements of Ag₁₂ nanoclusters.

Two electrons can be stored in the arene anchor of robust tripodal siloxide frameworks by chemical reduction of their Th(IV) complexes. The two electrons become available at the metal center for the controlled two-electron reduction of a broad range of substrates (N₂O, COT, CHT, Ph₂N₂, Ph₃PS and O₂) while the ligand framework is retained in its original form.

H₂S overproduction is linked to various disease states while chemical tools that can precisely downregulate H₂S are still lacking. In this work, selenoxide-containing compounds were found to be potent H₂S scavengers with promising antidotal effects for H₂S poisoning. Several diselenides were further developed as catalytic scavengers for both H₂S and H₂O₂.

Crystalline dual-porous pyridine-based CTF with in situ generated Fe-N₃ single-atom active sites has been synthesized for the first time. Benefiting from the unique structure of Fe-N₃ and the dynamic reversible microenvironment of metal active centers, few-layer Fe-CTF nanosheets exhibit remarkable electrocatalytic and Zn-air battery performance.

Triblock copolymers containing poly(L-lactic acid) hard blocks and poly(tetrahydrofuran-co-cyclohexene oxide) soft blocks were synthesized using redox-switchable catalysis. The polymers demonstrated improved flexibility and mechanical properties similar to thermoplastic elastomers and underwent depolymerization under reactive distillation using Lewis acid catalysts, showing the material can be chemically recycled for a circular plastics economy.

The bifunctional hollow sulfur matrix consisting binary atomically dispersed MnN₄ and CoN₄ hotspots was fabricated. And the catalytic matrix facilitated confined tandem electrocatalysis effects render the successive reversible conversion of both long- and short-chain polysulfide intermediators and mitigate the cathodic passivation within the Na₃Zr₂Si₂PO₁₂ ceramic membrane architectured solid-state Na−S cells.

Here we report the first investigation into the cytotoxic and immunogenic potential of a cobalt complex within the context of anti-cancer stem cell (CSC) drug discovery. The cobalt complex is able to deliver flufenamic acid to CSCs, which perturbs the inhibitory damage-associated molecular pattern axis and promotes immunogenic cell death. This subsequently leads to the phagocytosis of CSCs by macrophages.

Two giant metallo-macrocycles with double-layer and triple-layer concentric heptagonal structures (DA and TA, respectively) have been successfully assembled by embedding coordination sites in the ligand backbone. The angle between the two arms at position 4 of the central terpyridine (tpy) units increased after complexation with metal ions, leading to precise control over the topology.

A series of perfluoroalkyl-decorated noble-metal-free metal–organic frameworks [PCN-(BPY-CuI)-(TPDC-F_x), x=3, 5, 7, 11] are rationally fabricated through the stepwise solvent-assisted linker installation, post-synthetic fluorination and metalation, which showed excellent performance in catalyzing the one-pot four-component tandem reaction between alkyne, aldehyde, amine and flue gas CO₂ for the facile preparation of 2-oxazolidinones.

We implemented an asymmetric coordination Fe−S₁N₃ SAC with significant geometric distortion. The Fe−S₁N₃ sites demonstrate distinctive self-relaxation behavior in response to different adsorption intermediates during the CO₂RR process. The dynamic change in bond length enabled independent regulation of the *COOH and *CO intermediates adsorption energies, effectively breaking the linear scale relationship and enhancing the intrinsic activity.

Different lateral functionalized pillar[n]arenes can be obtained using Friedel–Crafts acylation. The irreversible nature of acylation results in the macrocycles being obtained selectively in terms of ring sizes and functional positions. Further derivatization of the ketones is also possible to afford various laterally modified pillar[n]arenes that cannot be accessed by general Friedel–Crafts alkylation reactions.

This work pinpointed the cause of the capacity degradation of Zn−MnO₂ batteries and established the dominance of the MnO₂/Mn²⁺ dissolution-deposition mechanism. Such a methodology circumvents the complicated characterization methods used in previous studies and provides a universal approach to accurately identify the reaction mechanism of other aqueous batteries.

A new two-photon fluorogenic probe, CatKP1, has been developed to detect cathepsin K and enable the real-time monitoring of osteoclast activity in hindlimb long bones during pathologic bone loss. This highlights the importance of CatKP1 as a valuable tool for studying aberrant osteoclast behavior and exploring new therapeutic strategies.

This work not only provides new insights into the design of COFs by regulating the amount of charge transfer channels and enhancing the rate-determining two-electron water oxidation to boost H₂O₂ photosynthesis, but also paves the way for the practical application of COFs-based photocatalysts in solar-driven synthesis.

The porosity's significance in metal–organic frameworks (MOFs) has often been overlooked in luminescent sensing applications. A luminescent MOF NKU-999 was synthesized with tailored pores for highly selective and quantitative p-xylene recognition. The sensing mechanism was investigated by single crystal X-ray diffraction and dynamic magnetic susceptibilities.

A Cl vacancy strategy results in a lower Fe oxidation state with sharp d-states characteristics to enhance the adsorption and activation of NO, which overcomes the sluggish kinetics of NORR and competitive HER over FeOCl-V_Cl, especially at low concentrations of NO, and improves the catalytic activity and selectivity towards NORR.

A simple and efficient strategy is developed to prepare polyoxometalate-based hybrid supramolecular polymers (POM-SPs) by interfacial orthogonal self-assembly. Owing to the dynamic nature of noncovalent interactions, POM-SP-based interfacial assemblies with redox or competitive agent responsiveness can be achieved.

Topochemical reduction of LaSrCoRuO₆ yields LaSrCoRuO₅ a phase containing Co³⁺O₆, Co¹⁺O₄ and Ru³⁺O₅ units, consistent with the coordination-geometry-driven disproportionation of Co²⁺ in an extended oxide.

An electrochemical alkene azidocyanation reaction that is compatible with both alkyl and aryl alkenes was developed. The reactions involving aryl alkenes could be obtained with good enantioselectivities by employing a chiral ligand. Notably, this method of alkene difunctionalization employs readily accessible reagents and is distinguished by its demonstrated functional group tolerance.

Using capture-SELEX, a non-G-quadruplex aptamer for selective hemin binding was obtained, and it did not bind to closely related protoporphyrin IX. The new aptamer doubled heat release compared to a classical G-quadruplex aptamer, indicating a fundamentally different way of hemin binding.

We report a small aqueous-soluble lanthanide antenna (PAnt) specifically designed to dynamically interact with lanthanide ions and act as an exchangeable dye, aiming at mitigating photobleaching in PLIM microscopy in cellulo. Our self-assembled lanthanide complex exhibited an exceptional photostability compared to traditional lanthanide cryptates, marking a significant advance in quantitative PLIM bioimaging.

Diadenosine tetraphosphate-RNA (Ap₄A-RNA) is found in human and rat cell lines. Its amount is not dependent on the intracellular concentration of Ap₄A. Ap₄A-RNA is decapped by two enzymes, NUDT2 and DXO. Even though Ap₄A-RNA is present in the same fraction as mRNA, it is not translated. However, it is recognized as self RNA by the innate immune system, as it does not elicit an immune response.

We report examples of C(sp²)−N, C(sp²)−S, and C(sp²)−P bond formations in water microdroplets at room temperature and without catalyst.

The [Fe]-hydrogenase cofactor contains an acyl- and two CO-ligands. Biosynthesis using stable isotopes demonstrated the formation of the acyl ligand from the carboxy group of the precursor, and MS/MS analysis indicated that the acyl and CO ligands exchanged during photolysis. Time-resolved infrared spectroscopy revealed the presence of an acyl-Fe(CO)₃ intermediate during photolysis, which could explain the acyl/CO ligand exchange.

A new photochemical method for deoxygenative hydroalkylation of a wide range of alkenes and lactic acid derivatives is reported. This approach utilizes thiophenol as a nucleophilic organic catalyst which forms the key intermediate of this transformation via an S_N2 process.

A reductive (3+2) annulation of lactams was developed through a sequential process consisting of iridium-catalyzed hydrosilylation of the lactam carbonyl group followed by iridium-catalyzed photoredox coupling with α-bromoacetic acid. The method was successfully applied to the four-step total synthesis of (±)-eburnamonine.

A deaminative radical-polar crossover strategy generating carbanions is reported. This so called “aza-Reformatsky” reaction leverages the use of redox-active imines and an iridium photocatalyst to generate a wide array of tertiary benzylic, heteroarylbenzylic and α-ester anions, which can be trapped with different electrophiles.

A catalyst-free highly regioselective and efficient o-diborylation of aryllithium with tetra(o-tolyl)diborane(4) has been developed, leading to a family of o-diborylarenes in very good yields under mild reaction conditions. Density functional theory calculations reveal that an aromatic nucleophilic C(sp²)−H substitution pathway may be involved.

An unprecedented (4+4) cycloaddition of simple 1,3-dienes with azadienes is achieved by π-Lewis basic palladium (0) catalysis, delivering benzofuran-fused eight-membered heterocycles in high efficiency, regio- and enantioselectivities. Highly diastereoselective derivatizations of the resultant eight-membered cyclic alkenes provide a facile access to diverse fused polycyclic compounds in excellent efficiency.

We report the protocol for decarboxylative radical sulfilimination reactions between sulfenamides and N-hydroxyphthalimide esters of primary, secondary, and tertiary alkyl carboxylic acids, which were achieved via a combination of photoredox, copper, and Brønsted base catalysis. The mild, operationally simple reaction has good functional group compatibility. Our findings provide a Brønsted base activation strategy for metallaphotoredox catalysis.

An in situ chiral template approach has been developed for the synthesis of homochiral lead iodides, demonstrating the advantage of using two different chiral templates over a single chiral template in enhancing the second-harmonic generation response.

Precise control of repeating reactions to form oligomeric compounds is challenging because such reactions are controlled only statistically. Here, we show that a coordination cage serves as a nano-reaction vessel in the iteroselective condensation of a simple aromatic compound and formaldehyde to form a methylene-bridged arene trimer. The confinement effect for the kinetic protection is also demonstrated by the subsequent iodination of the trimer within the cage.