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Organic molecular cages with low symmetry are promising to generate complex chemical environments for molecular recognition and catalysis. Herein, a new triangular prism cage with three rigid 8‐aminoquinoline‐2‐carboxylic acid derivatives as edges were synthesized. This molecular cage possesses reduced symmetry and contains both secondary amine and amide as hydrogen donating groups for molecular recognition. It could bind anions, such as NO3−, AcO−, and F− with moderate affinity. [ABSTRACT FROM AUTHOR]

The reaction of a sterically shielded Mg hydride complex, bearing a bulky β‐diketiminato (BDI) ligand, with CO2 leads to the formation of polynuclear complexes. CO2 not only inserts into the metal hydride bond yielding formate ions, but also adds onto the γ‐C of the BDI ligand. This reactivity gives rise to the formation of soluble tri‐ and tetranuclear structures in THF, leading to a hexameric structure associated with a change in the coordination mode of the BDI ligand at 60 °C in THF within four days. The insoluble hexameric complex was isolated in high reproducible yield from the solution and characterized by X‐ray diffraction analysis. The reaction affording the hexameric complex was shown to be completed within 1 h at room temperature in toluene. Similar reactions of CO2 with a BDI calcium hydride complex proceeds less cleanly and a pure product could not be isolated. [ABSTRACT FROM AUTHOR]

Nature uses various chiral and unsymmetric building blocks to form substantial and complex supramolecular assemblies. In contrast, the majority of organic ligands used in metallosupramolecular chemistry are symmetric and achiral. Here we extend the group of unsymmetric chiral bile acids used as a scaffold for organic bispyridyl ligands by employing chenodeoxycholic acid (CDCA), an epimer of the previously used ursodeoxycholic acid (UDCA). The epimerism, flexibility, and bulkiness of the ligands leads to large structural differences in coordination products upon reaction with Pd(NO3)2. The UDCA‐bispyridyl ligand self‐assembles quantitatively into a single crown‐like Pd3L6 complex, whereas the CDCA ligand provides a mixture of coordination complexes of general formula PdnL2n, i.e., Pd2L4, Pd3L6, Pd4L8, Pd5L10, and even Pd6L12 containing an impressive 120 chiral centers. The coordination products were studied by a combination of analytical methods, with ion‐mobility mass spectrometry (IM‐MS) providing valuable details on their structure and allowed an effective separation of m/z 1461 to individual signals according to the arrival time distribution, thereby revealing four different ions of [Pd3L6(NO3)3]3+, [Pd4L8(NO3)4]4+, [Pd5L10(NO3)5]5+, and [Pd6L12(NO3)6]6+. The structures of all the complexes were modelled using DFT calculations. Finally, the challenges and conclusions in determining the specific structural identity of these unsymmetric species are discussed. [ABSTRACT FROM AUTHOR]

The article reviews and categorizes the structures of tin oxo clusters with nuclearities ≥6 and compares them with oxo clusters of the other group 4 and 14 metals. Basic construction principles of the cluster core are worked out by comparing the different cluster types and by identifying smaller building blocks. The comparison also shows how the different cluster types are influenced by the interplay between the ligands which stabilize the cluster core and the bridging oxygen atoms. [ABSTRACT FROM AUTHOR]

Homometallic titanium oxo clusters (TOC) are one of the most important groups of metal oxo clusters. In a previous article, TOC structures with carboxylato and phosphonato ligands were reviewed and categorized. This work is now extended to clusters with other ligands. Comparison of the different cluster types shows how the interplay between condensation of the titanium polyhedra by means of bridging oxygen atoms and the coordination characteristics of the ligands influences the cluster structures and allows working out basic construction principles of the cluster core. [ABSTRACT FROM AUTHOR]

The mitochondrial calcium uniporter (MCU) mediates uptake of calcium ions (Ca2+) into the mitochondria, a process that is vital for maintaining normal cellular function. Inhibitors of the MCU, the most promising of which are dinuclear ruthenium coordination compounds, have found use as both therapeutic agents and tools for studying the importance of this ion channel. In this study, six Co3+ cage compounds with sarcophagine-like ligands were assessed for their abilities to inhibit MCU-mediated mitochondrial Ca2+ uptake. These complexes were synthesized and characterized according to literature procedures and then investigated in cellular systems for their MCU-inhibitory activities. Among these six compounds, [Co(sen)]3+ (3, sen = 5-(4-amino-2-azabutyl)-5-methyl-3,7-diaza-1,9-nonanediamine) was identified to be a potent MCU inhibitor, with IC50 values of inhibition of 160 and 180 nM in permeabilized HeLa and HEK293T cells, respectively. Furthermore, the cellular uptake of compound 3 was determined, revealing moderate accumulation in cells. Most notably, 3 was demonstrated to operate in intact cells as an MCU inhibitor. Collectively, this work presents the viability of using cobalt coordination complexes as MCU inhibitors, providing a new direction for researchers to investigate in future studies.

In order to discover of high-energy materials with characteristics that surpass modern benchmarks, it is necessary to study the widest range of potential structures. The design of energetic compounds using high-nitrogen cage scaffolds provides new opportunities. One of the promising representatives of polycyclic multinitragen cages is the hexaazaisowurtzitane, since the most powerful explosive CL-20 is based on it. In recent years, the synthesis of CL-20 analogues has been actively developed. This review presents progress in the synthesis, performance and study of the structure-property relationship for energetic polynitro hexaazaisowurtzitanes over the past decade.

The development of artificial light‐harvesting systems mimicking the natural photosynthesis method is an ever‐growing field of research. Numerous systems such as polymers, metal complexes, POFs, COFs, supramolecular frameworks etc. have been fabricated to accomplish more efficient energy transfer and storage. Among them, the supramolecular coordination complexes (SCCs) formed by non‐covalent metal‐ligand interaction, have shown the capacity to not only undergo single and multistep energy migration but also to utilize the harvested energy for a wide variety of applications such as photocatalysis, tunable emissive systems, encrypted anti‐counterfeiting materials, white light emitters etc. This review sheds light on the light‐harvesting behavior of both the 2D metallacycles and 3D metallacages where design ingenuity has been executed to afford energy harvesting by both donor ligands as well as metal acceptors. [ABSTRACT FROM AUTHOR]

Metal–organic cages (MOCs), which are formed via coordination‐driven assembly, are being extensively developed for various applications owing to the utility of their accessible molecular‐sized cavity. While MOC structures are uniquely and precisely predetermined by the metal coordination number and ligand configuration, tailoring MOCs to further modulate the size, shape, and chemical environment of the cavities has become intensively studied for a more efficient and adaptive molecular binding. Herein, we report self‐expanding MOCs that exhibit remarkable structural variations in cage size and flexibility while maintaining their topology. A cyclic ligand with an oligomeric chain tethering the two benzene rings of stilbene was designed and mixed with RhII ions to obtain the parent MOCs. These MOCs were successfully transformed into expanded MOCs via the selective cleavage of the double bond in stilbene. The expanded MOCs could effectively trap multidentate N‐donor molecules in their enlarged cavity, in contrast to the original MOCs with a narrow cavity. As the direct synthesis of expanded MOCs is impractical because of the entropically disfavored structures, self‐expansion using ring‐openable ligands is a promising approach that allows precision engineering and the production of functional MOCs that would otherwise be inaccessible. [ABSTRACT FROM AUTHOR]

Photodynamic therapy (PDT), as an emerging cancer treatment, requires the development of highly desirable photosensitizers (PSs) with integrated functional groups to achieve enhanced therapeutic efficacy. Coordination‐driven self‐assembly (CDSA) would provide an alternative approach for combining multiple PSs synergistically. Here, we demonstrate a simple yet powerful strategy of combining conventional chromophores (tetraphenylethylene, porphyrin, or Zn‐porphyrin) with pyridinium salt PSs together through condensation reactions, followed by CDSA to construct a series of novel metallo‐supramolecular PSs (S1–S3). The generation of reactive oxygen species (ROS) is dramatically enhanced by the direct combination of two different PSs, and further reinforced in the subsequent ensembles. Among all the ensembles, S2 with two porphyrin cores shows the highest ROS generation efficiency, specific interactions with lysosome, and strong emission for probing cells. Moreover, the cellular and living experiments confirm that S2 has excellent PDT efficacy, biocompatibility, and biosafety. As such, this study will enable the development of more efficient PSs with potential clinical applications. [ABSTRACT FROM AUTHOR]

Tetrahedral homonuclear tetrameric species are neutral or ionic tetrahedra of chemical elements, true molecular tetrahedra in strict geometrical sense. The aim of this work was to find all true elemental tetrahedra experimentally determined as stable and capable of being transferred from one medium/condition to another, to rationalize their structures and properties, and seek their technological significance. A database of elemental tetrahedra was built based on reliable literature, and a dataset of molecular descriptors was generated. Correlation analysis, hierarchical cluster analysis, principal component analysis, and some regression analysis were carried out. Twelve chemical elements from Groups 13 – 15 have tetrahedral species: anions E48– (Al, Ga, In, Tl), anions E44– (Si, Ge, Sn, Pb), neutral molecules E4 (P, As, Sb), and cations E4+ (P, As, Sb, Bi). These species appear in 39 forms, such as gas phase, solid Zintl phases, thin films, Zintl phase ammoniates, and cage compounds, among others. Zintl phases and forms of P4 and As4 are important for synthesis of new materials, chemical reactions, and other applications. Data compression has shown that the true tetrahedral species are a three-dimensional phenomenon, and that true tetrahedra can be distinguished from fictive tetrahedra. Grouping of the tetrahedra according to their periodic groups, charges, frequency, and diversity class values, tetrahedral size, and metallic character, were observed. Empirical rules for species size and principal components were established for true tetrahedra. Most descriptors are parabolic functions of the class variable. True tetrahedral species partly remain a puzzle and should be further investigated.

We report a novel strategy for reversible modulation of the supramolecular chirality based on guest‐facilitated heteroleptic assembly of helical anionocages. Two triple‐stranded helical anionocages including a chiral cage 1 (A2L13) and a crown ether functionalized achiral cage 2 (A2L23) were synthesized by anion coordination of bis‐monourea‐based ligands and PhPO32−. Both cages exhibited favorable binding with tetraethylammonium TEA+ and cobaltocenium Cob+ (endo‐guest, bound in the cavity). Additionally, cage 2 could reversibly release and recapture the guests through binding the exo‐guest potassium ions (K+) in the crown ethers and subsequent removal of the K+ by [2,2,2]‐cryptand. The circular dichroism (CD) spectrum of cage 1 was not significantly affected by guest encapsulation or mixing with the "empty" cage 2. However, in the presence of both cage 2 and an endo‐guest/exo‐guest, the Cotton effects were reversed at 391 nm and significantly enhanced at 310 nm. This observation was attributed to the guest‐facilitated formation of heteroleptic cages that enabled effective chirality transfer from the chiral to the achiral ligands. The CD changes induced by K+ could be fully reversed by removing it with [2,2,2]‐cryptand. Sequential addition and removal of K+ allowed reversible modulation of the chirality for at least 10 cycles without significant attenuation. [ABSTRACT FROM AUTHOR]

Developing luminescent materials that exhibit strong emissions in both solution and solid phases is highly desirable and challenging. Herein, we report imine‐bond directed formation of a rigid organic cage (TPE‐cage) that was synthesized by [2+4] imine condensation of a TPE‐cored tetra‐aldehyde (TPE‐TA) with a clip‐like diamine (XA) to illustrate confinement‐induced fluorescence enhancement. Compared to the non‐emissive TPE‐TA (ϕF=0.26 %) in the dichloromethane (DCM) solution, the TPE‐cage achieved a remarkable (~520‐fold) emission enhancement (ϕF=70.38 %). In contrast, a monomeric tetra‐imine model compound (TPE‐model) showed only a minor enhancement (ϕF=0.56 %) in emission compared to the parent tetra‐aldehyde TPE‐TA. The emission of TPE‐cage was further enhanced by ~1.5‐fold (ϕF=80.96 %) in the aggregated state owing to aggregation‐induced emission enhancement (AIEE). This approach establishes the potential for synthesizing luminescent materials with high emission in both solution and solid‐state by employing a single‐step imine condensation reaction. [ABSTRACT FROM AUTHOR]

A series of tetraaza‐expanded calix[4]arene analogues (2–4), in which two of the four aryl groups are ethylene‐protected thiophenol components were prepared from tetraaldehyde 1. Two of these strapped macrocycles were characterized crystallographically, as well as the dipalladium complex of 4. The same tetraaldehyde had been previously used for the synthesis of a macrotricycle (5) and a macropentacycle (6), the coordination properties of which have been investigated. In particular, ligand 6 was shown to be able to encapsulate a Cu+ or a Ag+ ion in the tetrahedral coordination pocket offered by a bridgehead nitrogen atom and the three proximal thioether sulfur atoms. [ABSTRACT FROM AUTHOR]

Chiral molecular switches are attracting attention as they could pave the way to chiral molecular machines. Herein, we report on the design and synthesis of a single molecule chiral switch based on a cyclotriveratrylene scaffold, in which the chirality inversion is controlled by the solvent. Hemicryptophanes are built around a C3 cyclotriveratrylene chiral unit, with either M or P handedness, connected to another tripod and usually displaying an "out" configuration. Here, we demonstrate that solvents are able to control the "in" and "out" configurations of the CTV unit, creating a chiral molecular switch from (M/P)"in" to (P/M)"out" handedness. The full characterization of the "in" and "out" configurations and of the chirality switch were made possible by combining NMR, HPLC, ECD, DFT and molecular dynamics. Interestingly, bulky aromatic solvents such as 2‐t‐butylphenol favor the "in" configuration while polar aprotic solvents such as acetone favor the "out" configuration. This chiral switch was found to be fully reversible allowing the system to oscillate between two different M and P configurations several times upon the action of solvents stimuli. [ABSTRACT FROM AUTHOR]

The bicyclic silicon(I) ring compound Si4{N(SiMe3)Mes}4 (2) was used as starting material in reactions with chalcogens and chalcogen transfer agents at low temperatures. This resulted in the selective formation of new cage compounds. With Me3NO, a silicon oxide with adamantane‐type cage 3 was isolated that represents the first isolated T4 silsesquioxane. Reactions with propylenesulfide and red selenium gave direct access to defect heterocubane‐type cages 4 and 5 with three Si−Si bonds wherein the silicon atoms adopt different low oxidation states of +I and +III. A reaction with elemental tellurium even occurs below room temperature to provide ditelluro−tetrasila−tricyclohexane 6. [ABSTRACT FROM AUTHOR]

The bicyclic silicon(I) ring compound Si4{N(SiMe3)Mes}4 (2) was used as starting material in reactions with chalcogens and chalcogen transfer agents at low temperatures. This resulted in the selective formation of new cage compounds. With Me3NO, a silicon oxide with adamantane‐type cage 3 was isolated that represents the first isolated T4 silsesquioxane. Reactions with propylenesulfide and red selenium gave direct access to defect heterocubane‐type cages 4 and 5 with three Si−Si bonds wherein the silicon atoms adopt different low oxidation states of +I and +III. A reaction with elemental tellurium even occurs below room temperature to provide ditelluro−tetrasila−tricyclohexane 6. [ABSTRACT FROM AUTHOR]

Through coordination‐driven self‐assembly, aesthetically captivating structures can be formed by tuning the length or flexibility of various components. The self‐assembly of an elongated rigid terphenyl‐based tetra‐pyridyl ligand (L1) with a cis‐Pd(II) acceptor produces an [M12L16]24+ triangular orthobicupola structure (1). When flexibility is introduced into the ligand by the incorporation of a ‐CH2‐ group between the dipyridylamine and terphenyl rings in the ligand (L2), anunique [M8L24]16+ water‐soluble 'intertwined cubic structure' (2) results. The inherent flexibility of ligand L2 might be the key factor behind the formation of the thermodynamically stable and ′intertwined cubic structure′ in this scenario. This research showcases the ability to design and fabricate novel, topologically distinctive molecular structures by a straightforward and efficient approach. [ABSTRACT FROM AUTHOR]

Tetrahedral homonuclear tetrameric species are neutral or ionic tetrahedra of chemical elements, true molecular tetrahedra in strict geometrical sense. The aim of this work was to find all true elemental tetrahedra experimentally determined as stable and capable of being transferred from one medium/condition to another, to rationalize their structures and properties, and seek their technological significance. A database of elemental tetrahedra was built based on reliable literature, and a dataset of molecular descriptors was generated. Correlation analysis, hierarchical cluster analysis, principal component analysis, and some regression analysis were carried out. Twelve chemical elements from Groups 13-15 have tetrahedral species: anions E4 8-(Al, Ga, In, Tl), anions E4 4-(Si, Ge, Sn, Pb), neutral molecules E4 (P, As, Sb), and cations E4 + (P, As, Sb, Bi). These species appear in 39 forms, such as gas phase, solid Zintl phases, thin films, Zintl phase ammoniates, and cage compounds, among others. Zintl phases and forms of P4 and As4 are important for synthesis of new materials, chemical reactions, and other applications. Data compression has shown that the true tetrahedral species are a three-dimensional phenomenon, and that true tetrahedra can be distinguished from fictive tetrahedra. Grouping of the tetrahedra according to their periodic groups, charges, frequency, and diversity class values, tetrahedral size, and metallic character, were observed. Empirical rules for species size and principal components were established for true tetrahedra. Most descriptors are parabolic functions of the class variable. True tetrahedral species partly remain a puzzle and should be further investigated. [ABSTRACT FROM AUTHOR]

Seed‐mediated growth has been widely used to synthesize noble metal nanoparticles with controlled size and shape. Although it is becoming possible to directly observe the nucleation process of metal atoms at the single atom level by using transmission electron microscopy (TEM), it is challenging to control the formation and growth of seeds with only a few metal atoms in homogeneous solution systems. This work reports site‐selective formation and growth of atomic scale seeds of the Au nanoparticle in a nanospace of an organic cage molecule. We synthesized a cage molecule with amines and phenols, which were found to both capture and reduce Au(III) ions to spontaneously form the atomic scale seeds containing Au(0) in the nanospace. The growth reaction of the atomic scale seeds afforded Au nanoparticles with an average diameter of 2.0±0.2 nm, which is in good agreement with the inner diameter of the cage molecule. [ABSTRACT FROM AUTHOR]

The excellent catalytic performances of enzymes in terms of activity and selectivity are an inspiration for synthetic chemists and this has resulted in the development of synthetic containers for supramolecular catalysis. In such containers the local environment and pre‐organization of catalysts and substrates leads to control of the activity and selectivity of the catalyst. Herein we report a supramolecular strategy to encapsulate single catalysts in a urea‐functionalized Fe4L6 cage, which can co‐encapsulate a functionalized urea substrate through hydrogen bonding. Distinguished selectivity is obtained, imposed by the cage as site isolation only allows catalysis through π activation of the substrate and as a result the selectivity is independent of catalyst concentration. The encapsulated catalyst is more active than the free analogue, an effect that can be ascribed to transitionstate stabilization rather than substrate pre‐organization, as revealed by the MM kinetic data. The simple strategy reported here is expected to be of general use in many reactions, for which the catalyst can be functionalized with a sulfonate group required for encapsulation. [ABSTRACT FROM AUTHOR]

The performance prerequisites for nonlinear optical (NLO) crystals encompass a substantial second‐harmonic generation (SHG), a considerable laser induced damage threshold, and a moderate degree of birefringence. Nevertheless, the presence of particular anions may result in deficiencies within certain properties. The utilization of mixed anionic groups has emerged as an effective strategy to achieve a balance among numerous performance parameters of NLO crystals, particularly in terms of SHG responses and bandgaps. Compared with other heteroanionic compounds, adduct‐type compounds feature more concise structures with specific properties. Herein, we aim to provide an overview of the recent advancements in adduct‐type NLO crystals, focusing on their structures and properties. Furthermore, we analyze the coordination chemistry and disadvantages involved in adducts, and discuss the current synthesis methods as well as future directions for further exploration. [ABSTRACT FROM AUTHOR]

Dynamic covalent chemistry (DCvC) is a powerful and widely applied tool in modern synthetic chemistry, which is based on the reversible cleavage and formation of covalent bonds. One of the inherent strengths of this approach is the perspective to reversibly generate in an operationally simple approach novel structural motifs that are difficult or impossible to access with more traditional methods and require multiple bond cleaving and bond forming steps. To date, these fundamentally important synthetic and conceptual challenges in the context of DCvC have predominantly been tackled by exploiting compounds of lighter p‐block elements, even though heavier p‐block elements show low bond dissociation energies and appear to be ideally suited for this approach. Here we show that a dinuclear organometallic bismuth compound, containing BiMe2 groups that are connected by a thioxanthene linker, readily undergoes selective and reversible cleavage of its Bi−C bonds upon exposure to external stimuli. The exploitation of DCvC in the field of organometallic heavy p‐block chemistry grants access to unprecedented macrocyclic and barrel‐type oligonuclear compounds. [ABSTRACT FROM AUTHOR]

Construction of metal–organic cages with unique architecture and guest binding abilities is highly desirable. Herein, we report the synthesis of a distorted trigonal cage (1) from a twisted tetratopic ligand (L) and a PdII acceptor. Surprisingly, 1 exhibited a complete structural reorganization of its building units in the presence of C70 and C60 to form guest‐encapsulated tetragonal cages, (C70)2@2 and (C60)2@2, respectively. These guest‐bound cages were found to be potential 1O2 generators, with the former effectively catalyzing two different varieties of 1O2‐mediated oxidation reactions. [ABSTRACT FROM AUTHOR]

Selective binding of chloride over the other most abundant anions in living organisms is pivotal due to its essential role in physiological functions. Herein, we report a template‐free Pd2L4 cage exhibiting high selectivity for medium‐sized halides (i. e. Cl−, Br−) in water owing to the size‐discriminatory nature of the cage cavity. In pure water, this cage displays high selectivity and micromolar affinity for chloride. The cage shows no binding towards other biologically more abundant essential anions such as phosphates, carboxylates, or bicarbonate. This cage shows an unprecedented nanomolar affinity with 1 : 1 binding stoichiometry for chloride in aqueous‐DMSO media. This high affinity was achieved with the best use of traditional hydrogen bonding and electrostatic interactions, as confirmed by single‐crystal X‐ray diffraction analysis. This well‐defined cage sequestrates F− by cleaving a B−F bond in BF4− in a facile manner in a nonpolar solvent or in the presence of excess ligand. This cage also demonstrates capture of the sub‐ppm chloride level that is present in commercial D2O samples. [ABSTRACT FROM AUTHOR]

Catalysis inside molecular cages and capsules has attracted an increasing amount of attention over the last decade. While many examples of the catalysis of reactions with cationic intermediates and transition states are known, those with anionic counterparts are scarce. One limiting factor is access to suitably sized cationic iminopyridine‐based cages that are stable towards water and anionic/nucleophilic guest molecules. This study aimed at identifying such suitable cages. In this full paper, we describe the journey that finally led to the synthesis of a novel iminopyridine‐based tetrahedron that can bind larger organic anions with binding constants of up to 850 M−1 in MeCN−d3/H2O=9 : 1. Importantly, it also displays stability in basic aqueous acetonitrile. Surprisingly, investigations towards catalysis of reactions with anionic transition states did not indicate rate accelerations in the presence of the cage. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: 2,4,6,8‐Tetraazanoradamantane skeleton is a unique rigid cage‐like organic structure that has not been established. In this article, a facile protocol to build all‐bridge‐position‐functionalized 2,4,6,8‐tetraazanoradamantane skeleton by condensation of glyoxal, primary amines and disubstituted malondialdehydes, which were in situ generated from 2,2‐dipropenyl‐1,3‐dioxolane or 4,4‐dimethoxyhepta‐2,5‐diene via ozonation, is reported for the first time. A variety of primary amines are compatible with this process, and the corresponding 2,4,6,8‐tetraalkyl‐2,4,6,8‐tetraazanoradamantane‐9‐one ethylene or methyl ketals were achieved in 16%—58% yields. N‐Benzyl group could be converted to other functionalities such as acetyl and nitro, which indicates the structural diversity of this scaffold. [ABSTRACT FROM AUTHOR]

A rare gyrobifastigium architecture (GB) was constructed by self‐assembly of a tetradentate donor (L) with PdII acceptor in DMSO. The GB was converted to its isomeric tetragonal barrel (MB) upon treatment with water. The hydrophobic cavity of MB has been explored for the encapsulation of zinc‐phthalocyanine (ZnPc), which is an excellent photosensitizer for photodynamic therapy (PDT). However, the poor water‐solubility and aggregation tendency are the main reasons for the suboptimal PDT performance of free ZnPc in the aqueous medium. Effective solubilization of ZnPc in an aqueous medium was achieved by encapsulating it in the cavity of MB. The inclusion complex (ZnPc⊂MB) showed enhanced singlet oxygen generation in water. Higher cellular uptake and anticancer activity of the ZnPc⊂MB compared to free ZnPc on HeLa cells indicate that encapsulation of ZnPc in an aqueous host is a potential strategy for enhancement of its PDT activity in water. [ABSTRACT FROM AUTHOR]

Inspired by the signal transduction function of organophosphates in biological systems, bioactive organophosphates were utilized for the first time as chiral nodes to dictate the stereoselective assembly of hydrogen‐bonded anionic cages. Phosphonomycin (antibiotics), tenofovir (antivirals), adenosine monophosphate (natural product, AMP) and clindamycin phosphate (antibiotics) were assembled with an achiral bis‐monourea ligand, thereby leading to the stereoselective formation of quadruple or triple helicates. The extent of the stereoselectivity could be enhanced by either lowering the temperature or adding stronger‐binding cations as templates. With the chiral anionic cages as the host, some enantioselectivity was achieved when binding chiral quaternary ammonium cations. [ABSTRACT FROM AUTHOR]

Heptacyclo[6.6.0.02,6.03,13.04,11.05,9.010,14] tetradecane, HCTD is a distinct class of carbocyclic cage molecule which features the uniquely fused eight five‐membered rings. The HCTD molecular frame is synthesized through the transition metal‐catalyzed dimerization of two norbornadiene units. Post‐assembly modifications of HCTD molecular frames have delivered diversely functionalized HCTD derivatives suitable for further modification. [ABSTRACT FROM AUTHOR]

The self‐assembly of 2,5‐diformylpyrrole, tris(2‐aminoethyl)amine, and silver(I) yielded, depending on the size and basicity of the anion, new cascade complexes or plenates, that is, cryptates incorporating Agnn+ clusters. The nature of the product was counterion‐dependent, and its formation was either driven by cascade anion binding or by argentophilic interactions stabilizing the cluster within the cavity. The reaction of plenates with tetrabutylammonium halides resulted in the protonation‐coupled replacement of the Ag33+ with anion(s), yielding cascade cryptates. [ABSTRACT FROM AUTHOR]

The presented work is a continuation of research on the reactivity of unsaturated borasilsesquioxanes under the conditions of common organometallic transformations. The catalytic hydrosilylation reaction with silanes, siloxanes and silsesquioxanes in presence of platinum catalyst was explored. The majority of the products were obtained in high yields (>90 %) and their structures were confirmed and characterized by spectroscopy and spectrometry, i. e. NMR and MALDI‐TOF‐MS. The most significant segment of the work is research on the spontaneous redistribution reaction of the alkoxy group from silane to borane moiety occurring in the obtained products, not being limited to the heterosilsesquioxane chemistry, however. The products were confirmed using GC‐MS, ESI‐MS methods and B3LYP exchange‐correlation, in order to ascertain formation of the silicon‐boron hybrid molecule. [ABSTRACT FROM AUTHOR]

Here we report the formation of giant {Mo126W30} polyoxometalate cages templated by π‐conjugated planar ligands. Their inorganic shells incorporate arrays of 18 stacked aromatic carboxylates, such as 1,3,5‐benzenetricarboxylate or 5‐nitroisophthalate, and the assembly is stabilized by multiple π–π interactions. NMR data confirmed that the cages are stable in solution and the inner aromatic templates can be postsynthetically replaced by selected aliphatic dicarboxylates, paving the way for endo‐functionalization and exploration of the reactivities within the cage cavities. [ABSTRACT FROM AUTHOR]

Photochemical studies on supramolecular hosts that can encapsulate small guest molecules commonly focus on three aspects: photoswitching the cage to release or trap the guest, the effect of the confining environment on the guest, and light‐induced exciton or charge transfer within the cage structure. Here, we exploit ultrafast spectroscopy to address how the guest alters the photoswitching characteristics of the cage. For this, the impacts of three disparate guest compounds on ring‐opening or ring‐closure of a dithienylethene (DTE) ligand in a photoswitchable DTE‐based coordination cage are juxtaposed. The guest modulates both outcome and timescale of the cage's photodynamics, by an interplay of structural strain, heavy‐atom effect, and enhancement of charge‐transfer processes exercised by the guest on the photo‐excited cage. The approach might prove beneficial for attuning the applicability of photoswitchable nanocontainers and desired guest compounds. [ABSTRACT FROM AUTHOR]

The recognition of small molecules in hydrophobic cavities in aqueous medium is a fundamental process in molecular biology. Previously, we described the synthesis and conformational switching of enantiopure alleno‐acetylenic cage receptors as well as their application as model systems to study in detail the interplay of space occupancy, conformation, complexation, and chiral recognition in organic solvents. Now, we report the synthesis of three enantiopure alleno‐acetylenic cage receptors functionalized with hydrophilic groups at their surface, which allows an extension of the studies to aqueous media. The new receptors show solvent‐ and guest‐induced binary conformational switching between an 'open' and a 'closed' cage conformation. Importantly, the chiroptical properties of the alleno‐acetylenic receptors are strongly conformation‐dependent, an effect that manifests itself upon guest inclusion. We used electronic circular dichroism titrations to quantitatively study the binding of small organic molecules inside the hydrophobic receptor cavity in methanolic water. [ABSTRACT FROM AUTHOR]

Metalation of N‐mesityl‐P,P‐diphenylphosphinic amide with nBuLi in toluene yields tetranuclear lithium N‐mesityl‐P,P‐diphenylphosphinimidate ([Ph2P(OLi)=N−Mes]4, 1). Metalation of Ph2P(O)−N(H)Mes with a mixture of dibutylmagnesium and butyllithium in DME leads to formation of dinuclear [Ph2P{OLi(dme)}=N−Mes]2 (2). Excess of Ph2P(O)−N(H)Mes gives dinuclear [Li(O−PPh2=N−Mes){Ph2P(=O)−N(H)−Mes}]2 (3) with three‐coordinate alkali ions. The metathetical approach via reaction of 1 with anhydrous magnesium bromide in ethereal solution yields [{(thf)LiBr}2{(thf)Li(O−PPh2=NMes)(Et2O)Li(O−PPh2=NMes)}] (4). Heterobimetallic Li/Mg compounds are not accessible by these protocols. Reactions of 1 with DME, with excess of Ph2P(O)−N(H)Mes or with LiBr allows the straightforward conversion to compounds 2, 3 and 4. [ABSTRACT FROM AUTHOR]

The use of "fuel" compounds to drive chemical systems out of equilibrium is currently of interest because of the potential for temporally controlled, responsive behavior. We have recently shown that transiently formed crown ethers exhibit counterintuitive templation effects when generated in the presence of alkali metal cations: "matched" cations, such as K+ with an 18‐crown‐6 analogue, suppress the formation of the macrocycles (negative templation). In this work, we describe two macrocyclic diacids that, on treatment with carbodiimides, give transient macrobicyclic cages analogous to polyether cages. Negative templation effects are observed for the smaller cage when generated in the presence of K+ and Na+, but there is a weak, but reproducible, positive templation effect in the presence of Li+. The larger cage behaves similarly in the presence of Li+, K+, Rb+, and Cs+, but differently with Na+, which appears to bind to both the cage and the initial macrocycle. [ABSTRACT FROM AUTHOR]

Synthesis of robust covalent macrocycles/cages via multiple amide‐bond forming reaction is highly challenging and generally it needs multistep reactions. One‐pot reaction of appropriate di‐/tri‐acyl chloride with a diamine generally results polymers or oligomers instead of discrete architectures. To overcome this limitation, a strategy is reported here using dynamic imine chemistry for facile construction of imine‐based macrocycle and cage upon treatment of a diamine with di‐ and tri‐aldehydes respectively, followed by post‐synthesis one‐step conversion of imine bonds to amides to form the desired robust macrocycle and cage containing multiple amide bonds. While the macrocycle was found to form aggregates in DMSO, the cage was intact without any aggregation. Six amide groups in the confined pocket of the cage made it an ideal receptor for selective binding of fluoride with very high selectivity (∼3× ${\times }$ 103 fold) over chloride, and it was silent towards other halides, phosphate, and other oxyanions. [ABSTRACT FROM AUTHOR]

Anionocages have been developed as a unique family of hydrogen bonded cages. However, strategies for constructing anionocages are mainly limited to that based on (PO43−)‐bisurea coordination, neither the ligands nor the anions lack the simplicity and diversity of the maturely developed analogues based on metal coordination (i.e. metallocage). We report herein a more simple strategy for anionocages design based on (RPO32−)‐monourea coordination, utilizing monourea rather than bisurea as the hydrogen binding donor, and RPO32− rather than PO43− as the acceptor. Two fluorescent, quadruple helicate anionocages were constructed by a bis‐monourea ligand, and dianions PhOPO32− (H1) or HOPO32− (H1A), respectively, which were capable of encapsulating a series of cation guests. As revealed by molecular modeling, H1 features remarkable guest‐adaptive cavity breathing without change of the quadruple helicate topology, which allowed the encapsulation of different sized guests in an "induced fit" manner. [ABSTRACT FROM AUTHOR]

Construction of lanthanide heterometallic complex is important for engineering multifunction molecular containers. However, it remains a challenge because of the similar ionic radii of lanthanides. Herein we attempt to prepare chiral lanthanide heterometallic tetrahedra. Upon crystallization with a mixture of [Eu2L3] and [Ln2L3] (Ln=Gd, Tb and Dy) helicates, a mixture of heterometallic EunLn'4‐n(L6) (n=0–4) tetrahedra was prepared. Selective formation of heterometallic tetrahedron was observed as MS deconvolution results deviated from statistical results. The formation of heterometallic tetrahedron was found to be sensitive to ionic radii as well as the ratio of the two helicates used in the crystallization. [ABSTRACT FROM AUTHOR]

Introduction of adamantane moieties on diamondoids such as adamantane, 2‐azaadamantane or diamantane by amide formation and reduction to the corresponding amine was performed in a straightforward and easy way by amidation under Schotten–Baumann conditions and reduction with BH3 ⋅ THF. The obtained amides and amines were studied in terms of structural properties towards the perspective of transformation into nanodiamonds. Crystal structure and dynamic NMR experiments of the most crowded amide obtained gave structural insights into the effect of bulkiness and steric strain on out‐of‐planarity of amide bonds (16.0°) and the kinetics and thermodynamics of amide bond rotation (ΔG≠298K=11.5–13.3 kcal ⋅ mol−1). [ABSTRACT FROM AUTHOR]

This work is dedicated to the 85th anniversary of the birthday of an outstanding scientist, professor, doctor of chemical sciences, honored worker of science and technology of Ukraine Lilia Ivanovna Kas'yan. L.I. Kasyan graduated from Odesa State University (1960). In 1965, she graduated from the Department of Organic Chemistry of Dnipropetrovsk University (1965). In 1970, she defended her candidate's thesis (PhD equivalent) «Synthesis and study of some epoxides of the bicyclo[2.2.1]heptane family», and in 1990 she defended her doctoral thesis (D.Sc. habilitation) «Epoxides of the alicyclic family. Stereochemistry, reactivity, and methods of synthesis». Since 1991, he has been a professor at the Department of Organic Chemistry at the Dnipropetrovsk State University (now Oles Honchar Dnipro National University). Her scientific works concerned the chemistry of epoxides of the alicyclic family, the study of their reactivity and the development of methods of synthesis. She headed the scientific school for the study of epoxy compounds. Based on her fundamental research many epoxy-containing compositions have been developed for chemical industry. A recognized specialist in the synthesis, stereochemistry and spectroscopy of cage-like compounds, including chemical agents with biological (pesticide and pharmacological) activity. Author of more than 500 scientific papers, including 4 books (monographs). She paid great attention to the creative education of young people, for a long time she headed the work with the student scientific society of the Department of Chemistry. More than 20 student scientific works performed under her supervision received the highest awards at regional and state contests, 17 PhD theses were defended. [ABSTRACT FROM AUTHOR]

We synthesized a high‐nuclear isopolymolybdate cluster (n‐Bu4N)6H2[{Mo24O48(OMe)32}{Mo24O52(OMe)28}2] ⋅ 25H2O ⋅ 6CH3CN (1) by using [Mo6O19]2− as the base precursor. Crystallographic characterization shows the cluster is composed of an anionic [{Mo24O48(OMe)32}]8− cage and two charge‐neutral [{Mo24O52(OMe)28}] cages. Supported by the electrospray ionization mass spectrometry study, the polyoxoanion structural unit [Mo24O48(CH3O)27]3− demonstrates strong stability in acetonitrile solution. Moreover, 1 exhibits good proton conductivity of 1.79×10−3 S cm−1 at 358 K and 98 % relative humidity. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: Herein, we demonstrate a very useful strategy to construct cage‐based metal‐organic frameworks (MOFs) with third‐order nonlinear‐optical properties. More specifically, by employing the Zr4L6 (L = embonate) cages to assembly with N‐contained ligands and Mn2+/Zn2+ ions, four Zr4L6‐cage‐based MOFs have been synthesized and structurally characterized. Among them, a 3D framework with strong aromatic π − π stacking force exhibits a good optical limiting effect. [ABSTRACT FROM AUTHOR]

Reaction of lanthanoid tris(3,5-dimethylpyrazolate) compounds, [Ln(Me2pz)3(thf)]2 (Ln = La 1a, Ce, Pr, Dy 1b, Yb, Lu) with potassium or lithium bistrimethylsilylamide and with or without added 3,5-dimethylpyrazole, or of lanthanoid tris(bistrimethylsilyl)amide complexes with potassium bistrimethylsilylamide and 3,5-dimethylpyrazole have yielded a variety of oxide centred Ln3 or Ln4/(K or Li)1-3 multinuclear cages, namely, [La4O(Me2pz)11K(thf)2] (2a), [La4O(Me2pz)11Li(Me2pzH)]⋅0.5Hexane (2b), [La4O(Me2pz)10(Me2pzH)] (2c) (from heating 1a in toluene), [Ce3O(Me2pz)9K2(dme)2] (3a), [Ce3O(Me2pz)9Li2(thf)2]⋅0.5Hexane (3b) and [Ce(Me2pz)5Li2(thf)3] (3c), which crystallized together, [Ce3O(Me2pz)10K3(thf)3] (3d), [Pr3O(Me2pz)10K3(thf)3] (4), [Dy3O(Me2pz)9K2(thf)2]·THF (5), [Yb3O(Me2pz)9K2(thf)2]·THF (6), and [Lu3O(Me2pz)9K2(thf)2]⋅THF (7). Crystals of {[K8(Me2pz)8(thf)2]⋅THF}∞ (8) were also obtained from the preparation of 7. From reaction of [Ce(Me2pz)3(thf)]2 with potassium tert-butoxide in toluene, the cerium(IV) heterobimetallic polymer [Ce2(Me2pz)6(OtBu)4K2]∞ (9) was isolated. In the Ln3O and the Ln4O cages, the Ln atoms have triangular and distorted tetrahedral arrangements about the central oxygen, respectively. All metals are bound to the cages by a variety of pyrazolate binding modes, with up to five different exhibited in some structures, and a new coordination mode, μ4-1κ(N):2κ(N'):η5:η5, was observed in two complexes., (© 2024 Wiley‐VCH GmbH.)

Coordination cages and their encapsulated cargo can be manoeuvred between immiscible liquid layers in a process referred to as phase transfer. Among the stimuli reported to drive phase transfer, counterion exchange is the most widespread. This method exploits the principle that counterions contribute strongly to the solubility preferences of coordination cages, and involves exchanging hydrophilic and hydrophobic counterions. Nevertheless, phase transfer of anionic cages remains relatively unexplored, as does selective phase transfer of individual cages from mixtures. Here we compare the phase transfer behaviour of two FeII4L6 cages with the same size and geometry, but with opposite charges. As such, this study presents a rare example wherein an anionic cage undergoes phase transfer upon countercation exchange. We then combine these two cages, and demonstrate that their quantitative separation can be achieved by inducing selective phase transfer of either cage. These results represent unprecedented control over the movement of coordination cages between different physical compartments, and are anticipated to inform the development of next-generation supramolecular systems., (© 2024 Wiley‐VCH GmbH.)

The advancements in targeted drug release and experimental neuroscience have amplified the scientific interest in photolabile protecting groups (PPGs) and photouncaging. The growing need for the detection of uncaging events has led to the development of reporters with fluorescence turn-on upon uncaging. In contrast, fluorescent tags with turn-off properties have been drastically underexplored, although there are applications where they would be sought after. In this work, a rhodamine-based fluorescent tag is developed with signal turn-off following photouncaging. One-photon photolysis experiments reveal a ready loss of red fluorescence signal upon UV (365 nm) irradiation, while no significant change is observed in control experiments in the absence of PPG or with irradiation around the absorption maximum of the fluorophore (595 nm). The two-photon photolysis of the turn-off fluorescent tag is explored in hydrogel photolithography experiments. The hydrogel-bound tag enables the power-, dwell time-, and wavelength-dependent construction of intricate patterns and gradients. Finally, a prominent caged neurotransmitter (MNI-Glu) is modified with the fluorescent tag, resulting in the glutamate precursor named as GlutaTrace with fluorescence traceability and turn-off upon photouncaging. GlutaTrace is successfully applied for the visualization of glutamate precursor distribution following capillary microinjection and for the selective excitation of neurons in a mouse brain model.

Abstract Introduction of adamantane moieties on diamondoids such as adamantane, 2‐azaadamantane or diamantane by amide formation and reduction to the corresponding amine was performed in a straightforward and easy way by amidation under Schotten–Baumann conditions and reduction with BH3 ⋅ THF. The obtained amides and amines were studied in terms of structural properties towards the perspective of transformation into nanodiamonds. Crystal structure and dynamic NMR experiments of the most crowded amide obtained gave structural insights into the effect of bulkiness and steric strain on out‐of‐planarity of amide bonds (16.0°) and the kinetics and thermodynamics of amide bond rotation (ΔG≠298K=11.5–13.3 kcal ⋅ mol−1).

The active site of particulate methane monooxygenase (pMMO) and its mechanism of action are not known. Recently, the CuC site emerged as a potential active site, but to date it lacks any study on biomimetic resemblance of the coordination environment provided by the enzyme. Here, the synthesis of a cage ligand providing such an environment is reported. Copper is incorporated, and coordination occurs by the two imidazole and one carboxylate group offered by the ligand. Depending on the oxidation state, it can adopt different coordination modes, as evidenced by the solid‐state structures and computational investigation. The copper(I) state readily reacts with dioxygen and thereby undergoes CH activation. Moreover, the catalytic aerobic oxidation of hydroquinones as ubiquinol mimics is shown. Clean one‐electron oxidation occurs under mild conditions and EPR analysis of the copper(II) state in the presence of water reveals striking similarities to the data obtained from pMMO. [ABSTRACT FROM AUTHOR]

Pyrrole‐based cryptand‐like cages are important owing to their three‐dimensional cavities together with three open crevices or clefts. The polar pyrrole subunits in the cages preorganize themselves to construct rigid and shape persistent molecular frameworks. Both the inner voids (cavity and cleft) are accessible to various guests such as metal ions, anions and, neutral molecules. The pyrrole ring offers hydrogen bond donor NH groups and its π‐electrons to bind anions or neutral molecules, whereas sigma donation of pyrrolides stabilizes metal ions. In addition, the orientation of bridgehead positions of the cryptand molecules along with specific conformations of the pyrrole rings and/or connecting arms dictate the size of available void space which is directly related to the selectivity for specific guest molecules to be recognized. Thus, the cages have attracted attention in recent times for the development of supramolecular chemistry. In this review, we summarize different synthetic procedures of laterally symmetrical cryptand‐like molecules, their structures, and applications in diverse aspects. [ABSTRACT FROM AUTHOR]