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The two-electron reductive activation of O2to O22–is of particular interest to the scientific community mainly due to the use of peroxides as green oxidants and in powerful fuel cells. Despite of the great importance of vanadium(IV) species to activate the two-electron reductive activation of O2, the mechanism is still unclear. Reaction of VIVO2+species with the tridentate-planar N,N,N-carboxamide (ΗL) ligands in solution (CH3OH:H2O) under atmospheric O2, at room temperature, resulted in the quick formation of [VV(═O)(η2-O2)(κ3-L)(H2O)] and cis-[VV(═O)2(κ3-L)] compounds. Oxidation of the VIVO2+complexes with the sterically hindered tridentate-planar N,N,N-carboxamide ligands by atmospheric O2gave only cis-[VV(═O)2(κ3-L)] compounds. The mechanism of formation of [VV(═O)(η2-O2)(κ3-L)(H2O)] (I) and cis-[VV(═O)2(κ3-L)] (II) complexes vs time, from the interaction of [VIV(═O)(κ3-L)(Η2Ο)2]+with atmospheric O2, was investigated with 51V, 1H NMR, UV–vis, cw-X-band EPR, and 18O2labeling IR and resonance Raman spectroscopies revealing the formation of a stable intermediate (Id). EPR, MS, and theoretical calculations of the mechanism of the formation of I and II revealed a pathway, through a binuclear [VIV(═O)(κ3-L)(H2O)(η1,η1-O2)VIV(═O)(κ3-L)(H2O)]2+intermediate. The results from cw-EPR, 1H NMR spectroscopies, cyclic voltammetry, and the reactivity of the complexes [VIV(═O)(κ3-L)(Η2Ο)2]+toward O2reduction fit better to an intermediate with a binuclear nature. Dynamic experiments in combination with computational calculations were undertaken to fully elucidate the mechanism of the O2reduction to O22–by [VIV(═O)(κ3-L)(Η2Ο)2]+. The galvanic cell {Zn|VIII,VII||Id, [VIVO(κ3-L)(H2O)2]+|O2|C(s)} was manufactured, demonstrating the important applicability of this new chemistry to Zn|H2O2fuel cells technology generating H2O2in situ from the atmospheric O2.

Based on the strong binding and high selectivity properties of 2,6-bis[hydroxy(methyl)amino]-4-morpholino-1,3,5-triazine (H2bihyat) for [UVIO2]2+, novel binucleating ligands (BLs) N,N′,N″,N‴-((1,4-phenylenebis(oxy))bis(1,3,5-triazine-6,2,4-triyl))tetrakis(N-methylhydroxylamine) (H4qtn), N1,N4-bis(4,6-bis(hydroxy(methyl)amino)-1,3,5-triazin-2-yl)benzene-1,4-diamine (H4pdl), and N1,N2-bis(4,6-bis(hydroxy(methyl)amino)-1,3,5-triazin-2-yl)ethane-1,2-diamine (H4enl) were synthesized. Binuclear complexes formed by coordination of hard metal ions with H4qtn are thermodynamically more stable than their mononuclear analogues with H2bihyat due to the increase in entropy accompanying the formation of more chelate rings. Reaction of either H4qtn or H4pdl or H4enl with [UVIO2]2+and [VVO2]+resulted in the isolation of the binuclear complexes [(UVIO2)2(μ-qtn)(H2O)4] (1), [(VVO2)2(μ-qtn)][PPh4]2[PPh4] (2), [(UVIO2)2(μ-pdl)(H2O)2(MeOH)2] (3), [(VVO2)2(μ-pdl)][PPh4]2(4), [(UVIO2)2(μ-enl)(H2O)4] (5), and [(VVO2)2(μ-enl)][PPh4]2(6). The binuclear complexes 1–6were characterized by single-crystal X-ray diffraction analysis in solid state and by NMR and ESI-MS in solution. The comparison of the coordination ability of the BLs with either pyridine-2,6-dicarboxylic acid (H2dipic) or H2bihyat or CO32–toward [UVIO2]2+and [VVO2]+was investigated by NMR and UV–vis spectroscopies and DFT theoretical calculations, revealing a superior performance of BLs. The selectivity of the BLs for [UVIO2]2+over [VVO2]+is decreased compared to that of H2bihyat but increases considerably at pH > 9 values. Formation of the mixed-metal binuclear species [UVIO2(μ-O)VVO2] influences the selectivity and dynamics of the reaction of H4qtn for [UVIO2]2+and [VVO2]+in aqueous solution. The results of this study provide crucial information for the ligand design and the development of stronger and more selective systems.

Efficient separation of water-in-oil emulsion is of great importance but remains highly challenging since such emulsion contains stable tiny droplets with a diameter less than 20 μm. Herein, we reported the fabrication of a modular fibrous functional membrane using an “in situ growth and covalent functionalization” strategy. The as-prepared PAN@LDH@OTS (PAN = polyacrylonitrile; LDH = layered double hydroxides; and OTS = octadecyltrichlorosilane) membrane possessed an interlaced rough nanostructured surface with intriguing superhydrophobic/superlipophilic properties. When applied for the separation of surfactant-stabilized water-in-oil emulsion (SSE), the PAN@LDH@OTS membrane exhibited an ultrahigh permeation flux of up to 4.63 × 104L m–2h–1with an outstanding separation efficiency of >99.92%, outperforming most of the state-of-the-art membranes. In addition, the membrane can maintain a stable permeation flux and superhydrophobic/superlipophilic properties after 20 times of use. Detailed characterization demonstrated that the demulsification of the SSE process was as follows: first, the droplets can be easily adsorbed to the PAN@LDH@OTS membrane due to the improved intermolecular interactions between OTS and the surfactants (Span 80); second, the droplets can be deformed by the electropositive LDH laminate; and third, the deformed tiny emulsion droplets coalesced into large droplets and floated up, and as a result, efficient separation of SSE can be achieved.

Hafnium(IV) molecular species have gained increasing attention due to their numerous applications ranging from high-resolution nanolithography, heterogeneous catalysis, and electronics to the design of molecule-based building blocks in metal–organic frameworks (MOFs), with applications in gas separation, sorption, luminescence sensing, and interim storage of radioactive waste. Despite great potential, their chemistry is relatively underdeveloped. Here, we use strong chelators (2Z-6Z)-piperidine-2,6-dione (H3pidiox) and 2,3-dihydroxybenzaldehyde oxime (H3dihybo) to synthesize the first ever reported pentanuclear {Hf5/H3pidiox} and hexanuclear {Hf6/H3dihybo} clusters (HfOCs). The {Hf6} clusters adopt unique core structures [Hf6IV(μ3-O)2(μ-O)3] with a trigonal-prismatic arrangement of the six hafnium atoms and have been characterized via single-crystal X-ray diffraction analysis, UV–vis spectroscopy in the solid state, NMR, fluorescence spectroscopy, and high-resolution mass spectrometry in solution. One-dimensional (1D) and two-dimensional (2D) 1H NMR and mass spectroscopies reveal the exceptional thermodynamic stability of the HfOCs in solution. Interestingly, the conjunction of the oxime group with the catechol resulted in the remarkable reduction of the clusters’ band gap, below 2.51 eV. Another prominent feature is the occurrence of pronounced metalloaromaticity of the triangular {Hf3} metallic component revealed by its NICSzzscan curve calculated by means of density functional theory (DFT). The NICSzz(1) value of −44.6 ppm is considerably higher than the −29.7 ppm found at the same level of theory for the benzene ring. Finally, we investigated the luminescence properties of the clusters where 1emits light in the violet region despite the lack of fluorescence of the free H3pidiox ligand, whereas the {Hf6} 3shifts the violet-emitting light of the H3dihybo to lower energy. DFT calculations show that this fluorescence behavior stems from ligand-centered molecular orbital transitions and that HfIVcoordination has a modulating effect on the photophysics of these HfOCs. This work not only represents a significant milestone in the construction of stable low-band-gap multinuclear HfIVclusters with unique structural features and metal-centered aromaticity but also reveals the potential of Hf(IV) molecule-based materials with applications in sensing, catalysis, and electronic devices.

Reaction of VIVOCl2with the nonplanar tetradentate N4bis-quinoline ligands yielded four oxidovanadium(IV) compounds of the general formula cis-[VIV(O)(Cl)(N4)]Cl. Sequential treatment of the two nonmethylated N4oxidovanadium(IV) compounds with KF and NaClO4resulted in the isolation of the species with the general formula cis-[VIV(O)(F)(N4)]ClO4. In marked contrast, the methylated N4oxidovanadium(IV) derivatives are inert toward KF reaction due to steric hindrance, as evidenced by EPR and theoretical calculations. The oxidovanadium(IV) compounds were characterized by single-crystal X-ray structure analysis, cw EPR spectroscopy, and magnetic susceptibility. The crystallographic characterization showed that the vanadium compounds have a highly distorted octahedral coordination environment and the d(VIV–F) = 1.834(1) Å is the shortest to be reported for (oxido)(fluorido)vanadium(IV) compounds. The experimental EPR parameters of the VIVO2+species deviate from the ones calculated by the empirical additivity relationship and can be attributed to the axial donor atom trans to the oxido group and the distorted VIVcoordination environment. The vanadium compounds act as catalysts toward alkane oxidation by aqueous H2O2with moderate ΤΟΝ up to 293 and product yields of up to 29% (based on alkane); the vanadium(IV) is oxidized to vanadium(V), and the ligands remain bound to the vanadium atom during the catalysis, as determined by 51V and 1H NMR spectroscopies. The cw X-band EPR studies proved that the mechanism of the catalytic reaction is through hydroxyl radicals. The chloride substitution reaction in the cis-[VIV(O)(Cl)(N4)]+species by fluoride and the mechanism of the alkane oxidation were studied by DFT calculations.

Thermal insulation materials show a substantial impact on civil and military fields for applications. Fabrication of efficient, flexible, and comfortable composite materials for thermal insulation is thereby of significance. Herein, a “fiber templated epitaxial growth” strategy was adopted to construct PAN@LDH (PAN = polyacrylonitrile; LDH = layered double hydroxides) composite membranes with a three-dimensional (3D) network structure. The PAN@LDH showed an impressive temperature difference of 28.1 °C as a thermal insulation material in the hot stage of 80 °C with a thin layer of 0.6 mm. Moreover, when a human hand was covered with 3 layers of the PAN@LDH-70% composite membrane, it was rendered invisible under infrared radiation. Such excellent performance can be attributed to the following reasons: (1) the hierarchical interfaces of the PAN@LDH composite membrane reduced thermal conduction, (2) the 3D network structure of the PAN@LDH composite membranes restricted thermal convection, and (3) the selective infrared absorption of LDHs decreased thermal radiation. When modified with Dodecyltrimethoxysilane (DTMS), the resulting PAN@LDH@DTMS membrane can be used under high humidity conditions with excellent thermal insulation properties. As such, this work provides a facile strategy for the development of high-performance thermal insulation functional membranes.

The term self-assembly is used to describe the formation of many molecules and supramolecular architectures, but often, the precise mechanism is neglected. Here, we have investigated the kinetics of the self-assembly of the simplest heteropolyoxoanion, the Keggin ion [XMo12O40]x–. This study used variable temperature UV/vis spectroscopy to show that the Keggin ion can catalyze its own formation via an autocatalytic cycle. Kinetic investigations with real-time monitoring of the [XMo12O40]x–family’s formation reaction revealed key traits of autocatalytic systems, including kinetic saturation and concentration dependence of the incubation period. We explored the effect of the heteroatom on the kinetics of the autocatalytic process by investigating and comparing the formation rates of {AsMo12} and {SiMo12}. Finally, real-time electrospray ionization mass spectrometry studies of the reaction mixtures assist in the identification of the species involved in the formation process of the Keggin species, and these were explored using a stochastic model, which confirms our experimental observations.

The catalytic efficacy of a novel mononuclear rhenium(I) complex in CO2reduction is remarkable, with a turnover number (TONCO) of 1517 in 3 h, significantly outperforming previous Re(I) catalysts. This complex, synthesized via a substitution reaction on an aromatic ring to form a bromo-bipyridine derivative, L1= 2-bromo-6-(1H-pyrazol-1-yl)pyridine, and further reacting with [Re(CO)5Cl], results in the facial-tricarbonyl complex [ReL1(CO)3Cl] (1). The light green solid was obtained with an 80% yield and thoroughly characterized using cyclic voltammetry, nuclear magnetic resonance (NMR), Fourier transform infrared (FTIR) spectroscopy, and ultraviolet–visible (UV–vis) spectroscopy. Cyclic voltammetry under CO2atmosphere revealed three distinct redox processes, suggesting the formation of new electroactive compounds. The studies on photoreduction highlighted the ability of the catalyst to reduce CO2, while NMR, FTIR, and electrospray ionization (ESI) mass spectrometry provided insights into the mechanism, revealing the formation of solvent-coordinated complexes and new species under varying conditions. Additionally, computational studies (DFT) were undertaken to better understand the electronic structure and reactivity patterns of 1, focusing on the role of the ligand, the spectroscopic features, and the redox behavior. This comprehensive approach provides insights into the intricate dynamics of CO2photoreduction, showcasing the potential of Re(I) complexes in catalysis.

The chelating catechol/oxime ligand 2,3-dihydroxybenzaldehyde oxime (H3dihybo) has been used to synthesize one titanium(IV) and two zirconium(IV) compounds that have been characterized by single-crystal X-ray diffraction and 1H and 13C NMR, solid-state UV–vis, and ESI-MS spectroscopy. The reaction of TiCl4with H3dihybo and KOH in methanol, at ambient temperature, yielded the hexanuclear titanium(IV) compound K2[TiIV6(μ3-O)2(μ-O)3(OCH3)4(CH3OH)2(μ-Hdihybo)6]·CH3OH (1), while the reaction of ZrCl4with H3dihybo and either nBu4NOH or KOH also gave the hexanuclear zirconium(IV) compounds 2and 3, respectively. Compounds 1–3have the same structural motif [MIV6(μ3-Ο)2(μ-Ο)3] (M = Ti, Zr), which constitutes a unique example with a trigonal-prismatic arrangement of the six zirconium atoms, in marked contrast to the octahedral arrangement of the six zirconium atoms in all the Zr6clusters reported thus far, and a unique Zr6core structure. Multinuclear NMR solution measurements in methanol and water proved that the hexanuclear clusters 1and 3retain their integrity. The marriage of the catechol moiety with the oxime group in the ligand H3dihybo proved to be quite efficient in substantially reducing the band gaps of TiO2and ZrO2to 1.48 and 2.34 eV for the titanium and zirconium compounds 1and 3, respectively. The application of 1and 3in photocurrent responses was investigated. ESI-MS measurements of the clusters 1and 3revealed the existence of the hexanuclear metal core and also the initial formation of trinuclear M3(M = Ti, Zr) building blocks prior to their self-assembly into the hexanuclear M6(M = Ti, Zr) species. Density functional theory (DFT) calculations of the NICSzzscan curves of these systems revealed that the triangular M3(M = Ti, Zr) metallic ring cores exhibit pronounced metalloaromaticity. The latter depends upon the nature of the metallic center with NICSzz(1) values equal to −30 and −42 ppm for the Ti (compound 1) and Zr (compound 2) systems, respectively, comparable to the NICSzz(1) value of the benzene ring of −29.7 ppm calculated at the same level of theory.

Understanding magnetic anisotropy and specifically how to tailor it is crucial in the search for high-temperature single-ion magnets. Herein, we investigate the magnetic anisotropy in a six-coordinated cobalt(II) compound that has a complex geometry and distinct triaxial magnetic anisotropy from the perspective of the electronic structure, using electronic spectra, ab initio calculations, and an experimental charge density, of which the latter two provides insight into the d-orbital splitting. The analysis showed that the d-orbital splitting satisfactorily predicted the complex triaxial magnetic anisotropy exhibited by the compound. Furthermore, a novel method to directly compare the ab initio results and the d-orbital populations obtained from the experimental charge density was developed, while a topological analysis of the density provided insights into the metal–ligand bonding. This work thus further establishes the validity of using d-orbitals for predicting magnetic anisotropy in transition metal compounds while also pointing out the need for a more frequent usage of the term triaxial anisotropy in the field of single-molecule magnetism.

Traditionally, chemists have relied on years of training and accumulated experience in order to discover new molecules. But the space of possible molecules is so vast that only a limited exploration with the traditional methods can be ever possible. This means that many opportunities for the discovery of interesting phenomena have been missed, and in addition, the inherent variability of these phenomena can make them difficult to control and understand. The current state-of-the-art is moving toward the development of automated and eventually fully autonomous systems coupled with in-line analytics and decision-making algorithms. Yet even these, despite the substantial progress achieved recently, still cannot easily tackle large combinatorial spaces, as they are limited by the lack of high-quality data. Herein, we explore the utility of active learning methods for exploring the chemical space by comparing the collaboration between human experimenters with an algorithm-based search against their performance individually to probe the self-assembly and crystallization of the polyoxometalate cluster Na6[Mo120Ce6O366H12(H2O)78]·200H2O (1). We show that the robot-human teams are able to increase the prediction accuracy to 75.6 ± 1.8%, from 71.8 ± 0.3% with the algorithm alone and 66.3 ± 1.8% from only the human experimenters demonstrating that human-robot teams can beat robots or humans working alone.

Polyoxometalates (POMs) have been found to be good end-capping ligands for gold nanoparticles (AuNPs). Herein, we introduce a new synthetic method to synthesize gold nanoparticle–POM hybrids by heating a solution of AuNO3(PMe3) in acetonitrile in the presence of appropriate POM species with tetrabutylammonium (TBA) as a countercation at 120 °C in a microwave. This method allowed us to produce POM-capped AuNPs without over-reduction of the solution causing decomposition or reorganization of the POMs. Analysis of the resulting material by transmission electron microscopy showed that the POM’s size, charge, and functionality are key factors controlling the resulting POM–AuNP hybrid structure. Additionally, the reaction was monitored by electrospray ionization mass spectrometry (ESI-MS), ultraviolet–visible spectroscopy, and dynamic light scattering. The ESI-MS studies reveal crucial information regarding the nature of the reaction that takes place, showing the cation exchange between Au(I) and TBA cations, followed by self-reduction of the Me3PAu(I)–POM complex.

The electrocatalytic hydrogen evolution reaction (HER) is of central importance for the production of H2from sustainable sources. Currently, Pt is the best electrocatalyst for this transformation, but other materials based on less‐precious elements are now attracting increased attention. Of these alternatives, the molybdenum chalcogenides show particular promise. MoS2has been explored extensively in this regard, which has highlighted the important role of polymorphism for catalytic activity. However, the conversion into an active polymorph is complex, and the stability of the catalyst under electrochemical conditions is poor. In contrast, MoTe2has been barely studied as an electrocatalyst for the HER. Herein, we isolate the semiconducting and metallic polymorphs of MoTe2using an easy solid‐state route and show that interconversion between the two polymorphs of MoTe2can be achieved without a change in morphology by a simple temperature‐annealing protocol. Although the semiconducting form is a rather poor electrocatalyst for the HER, the metallic 1T′‐MoTe2polymorph is an efficient and stable electrocatalyst for the HER in 1 mH2SO4. Even in the bulk form, it achieved a low overpotential with a Tafel slope of (78±4) mV dec−1and full Faradaic efficiency. These findings highlight the importance of polymorphic control in the development of HER catalysts and suggest an efficient route for the discovery of new and improved electrocatalysts. Shapeshifters: Polymorphic control offers an effective route to active electrocatalysts for hydrogen evolution from water splitting. The facile polymorphic interconversion developed in this work preserves the catalyst morphology and allows the comparison of the electrocatalytic activities of both semiconducting and metallic MoTe2. The metallic 1T′‐MoTe2polymorph is a superior catalyst for the hydrogen evolution reaction when compared to the semiconducting 2H‐MoTe2.

Chemical transformations are normally conducted in batch or flow mode, thereby allowing the chemistry to be temporally or spatially controlled, but these approaches are not normally combined dynamically. However, the investigation of the underlying chemistry masked by the self-assembly processes that often occur in one-pot reactions and exploitation of the potential of complex chemical systems requires control in both time and space. Additionally, maintaining the intermediate constituents of a self-assembled system “off equilibrium” and utilizing them dynamically at specific time intervals provide access to building blocks that cannot coexist under one-pot conditions and ultimately to the formation of new clusters. Herein, we implement the concept of a programmable networked reaction system, allowing us to connect discrete “one-pot” reactions that produce the building block{W11O38} ≡ {W11} under different conditions and control, in real time, the assembly of a series of polyoxometalate clusters {W12O42} ≡ {W12}, {W22O74} ≡ {W22} 1a, {W34O116} ≡ {W34} 2a, and {W36O120} ≡ {W36} 3a, using pH and ultraviolet–visible monitoring. The programmable networked reaction system reveals that is possible to assemble a range of different clusters using {W11}-based building blocks, demonstrating the relationship between the clusters within the family of iso-polyoxotungstates, with the final structural motif being entirely dependent on the building block libraries generated in each separate reaction space within the network. In total, this approach led to the isolation of five distinct inorganic clusters using a “fixed” set of reagents and using a fully automated sequence code, rather than five entirely different reaction protocols. As such, this approach allows us to discover, record, and implement complex one-pot reaction syntheses in a more general way, increasing the yield and reproducibility and potentially giving access to nonspecialists.

POM in POM: Eine Wells‐Dawson‐Polyoxometallat‐Sandwichverbindung mit einem Doppelcubankern aus sechs Vanadiumatomen wurde synthetisiert (siehe Struktur). Die Clusterbildung wurde massenspektrometrisch verfolgt und der Reduktionsprozess des Doppelcubans durch spektroelektrochemische Massenspektrometrie untersucht.

POM‐in‐POM: A Wells–Dawson polyoxometalate sandwich compound with a double cubane core consisting of six vanadium atoms has been synthesized (see structure). Cluster formation was followed by mass spectrometry and the reduction of the double cubane was studied by a novel technique combining mass spectrometry and spectroelectrochemistry.

The nanosized, 2.2 nm, {Mo40} oxo(thio)metalate wheel was isolated in high yield using a direct synthetic procedure which involves acidification of a molybdate solution in the presence of the {Mo2O2S2}2+oxothio cation as the starting material. The [(Mo8O28)4(Mo2O2S2)4]24–wheel, 1a, was characterised by single‐crystal X‐ray diffraction analysis, IR, Raman, UV/Vis and flame atomic absorption spectroscopy (FAAS). Solid state and solution Raman spectroscopic studies allowed the unambiguous determination of the critical conditions by which compound 1retains its integrity in solution. Electrospray ionisation mass spectrometry (ESI‐MS) studies carried out on aqueous solutions of the crystalline material showed that the nanosized wheel retains its integrity in concentrated solutions. High resolution ESI‐MS studies allowed the direct observation of the discrete wheel as well as the distinct self‐assembly stages of its formation; from the fundamental building units through to the final formation of well resolved aggregations of 1D chains which is in agreement with the solid state studies.

Three's a charm: The title compound (see picture, right, WO6purple polyhedra, Mn orange and brown, Si green, O red) contains an embedded mixed‐valence {Mn5O6} cubane core, which is structurally similar to the active site in photosystem II. Solid‐, solution‐, and gas‐phase studies indicate the presence of three lacunary Keggin fragments, thereby giving insight into the complex solution chemistry of plenary POM fragments.

Cubanisches Herz: Der rechts im Bild gezeigte Komplex (WO6lila Polyeder, Mn orange und braun, Si grün, O rot) enthält einen gemischtvalenten {Mn5O6}‐Cubankern mit Strukturähnlichkeit zum aktiven Zentrum des Photosystems II. Festkörper‐, Lösungs‐ und Gasphasenstudien sprechen für das Vorhandensein dreier lakunärer Keggin‐Fragmente und geben so einen Einblick in die komplexe Lösungschemie vollständiger Polyoxometallatfragmente.

The design and assembly of redox active polyoxometalate clusters, and their potential as water oxidation catalysts is discussed. The activity of the clusters is placed into context with comparisons to other systems and routes to the design and solution control of the assembly of novel polyoxometalate clusters with the correct characteristics for catalysis is also presented. Building on these features, a potential new polyoxometalate-based device architecture is presented that combines redox active polyoxometalate clusters, using systems that have been shown to be good water oxidation catalysts or structural models for photosystem II, with large cationic dyes to produce microtubular architectures that can be deposited on transparent substrates. The combination of a range of highly redox and catalytically active polyoxometalates with a range of possible cationic dye candidates allows the development of modular device architectures that can be screened and developed as potential new solar fuel cells.

A series of tris(hydroxymethyl)aminomethane (TRIS)‐based linear (bis(TRIS)) and triangular (tris(TRIS)) ligands has been synthesised and were covalently attached to the Wells–Dawson type cluster [P2V3W15O62]9−to generate a series of nanometer‐sized inorganic–organic hybrid polyoxometalate clusters. These huge hybrids, with a molecular mass similar to that of small proteins in the range of ≈10–16 kDa, were unambiguously characterised by using high‐resolution ESI‐MS. The ESI‐MS spectra of these compounds revealed, in negative ion mode, a characteristic pattern showing distinct groups of peaks corresponding to different anionic charge states ranging from 3−to 8−for the hybrids. Each peak in these individual groups could be unambiguously assigned to the corresponding hybrid cluster anion with varying combinations of tetrabutylammonium (TBA) and other cations. This study therefore highlights the prowess of the high‐resolution ESI‐MS for the unambiguous characterisation of large, nanoscale, inorganic–organic hybrid clusters that have huge mass, of the order of 10–16 kDa. Also, the designed synthesis of these compounds points to the fact that we were able to achieve a great deal of structural pre‐design in the synthesis of these inorganic–organic hybrid polyoxometalates (POMs) by means of a ligand design route, which is often not possible in traditional “one‐pot” POM synthesis.

Ein flüchtiger Blick: Mit Elektrospray‐Ionisations‐Massenspektrometrie ist es möglich, in Lösung und Echtzeit die Bildung eines organisch‐anorganischen Polyoxometallathybridsystems zu beobachten (siehe Bild). Damit gelang es, Einblick in die Umlagerung des [α‐Mo8O26]4−‐Clusters zu erhalten, die bei der Bildung des Tris(hydroxymethyl)aminomethan‐koordinierten Mangan‐Anderson‐Clusters in Gegenwart von Mn(CH3CO2)3abläuft.

Catching a glimpse: Electrospray ionization mass spectrometry (ESI‐MS) allows monitoring of the real‐time, “in‐solution” formation of an organic–inorganic polyoxometalate hybrid system (see picture). This has provided insight into the rearrangement involved in the formation of the manganese‐Anderson cluster coordinated with tris(hydroxymethyl)aminomethane ligands, through the rearrangement of the [α‐Mo8O26]4−cluster in the presence of Mn(CH3CO2)3.

The exploration of the self-organization of a range of the polyoxometalate-based molecular structures reveals a diverse range of surface patterns and morphologies on solid substrates of technological interest, including methylated and hydroxylated silicon surfaces (namely, SiCH3and SiOH). By exploiting the interplay between the intrinsic molecular properties and the surface chemistry as well as dynamic spatiotemporal phenomena (e.g., dewetting), we show that these systems can yield 0D, 2D, and 3D architectures via solution deposition at the solid surface, including nanodots, discs, lamellas, porous networks, and layer-by-layer assemblies. In general, we observed that layer-by-layer growth is a common feature on low surface energy SiCH3. In addition, the polyoxometalate derived architectures are able to effectively modulate the drop spreading dynamics on high surface energy SiOH, so that dewetting induces the formation of nanodots from dilute solutions of the precursor POM hybrid, whereas using high concentration results in the formation of complex architectures whose shape depends on the molecular structure of the POM-based building block utilized. Finally, we show that hybrid POM derivatives with one or more functional moieties can be organized in an ordered fashion, thus yielding interesting model systems for the assembly of POM-based multifunctional nanostructures on surfaces.

Alloy, alloy: A pure cobalt‐based Keggin network linked by W‐O‐Co interactions is “alloyed” with a pure manganese‐based Keggin network, linked by W‐O‐Mn interactions. These isostructural alloys are solid solutions of the Co and Mn nets. The alloys are prepared by the stoichiometric mixing of the components of each discrete network, leading to a series of single‐crystalline mixed transition‐metal frameworks with novel redox properties.

Ein reines Cobalt‐Keggin‐Gerüstmit W‐O‐Co‐Wechselwirkungen wurde mit einem reinen Mangan‐Keggin‐Gerüst mit W‐O‐Mn‐Wechselwirkungen „legiert“. Die isostrukturellen Legierungen sind feste Lösungen der Co‐ und Mn‐Netze. Eine Reihe einkristalliner gemischter Gerüste mit neuartigen Redoxeigenschaften wurde durch Mischen der Komponenten jedes einzelnen Übergangsmetallgerüsts im entsprechenden stöchiometrischen Verhältnis erhalten.

Groß, größer, am größten: Die Polyoxoniobat‐Anionen [HNb27O76]16−und [H10Nb31O92(CO3)]23−– die größten bisher beschriebenen Polyoxoniobate – enthalten pentagonale Nb(Nb)5‐Bausteine, in denen das zentrale Nb‐Ion siebenfach koordiniert ist. Die Nb27‐Verbindung wurde durch ESI‐MS nachgewiesen, was eine gewisse Stabilität in Lösung belegt; die Nb31‐Verbindung ist chiral und enthält im Außenbereich des Clusters einen Carbonatliganden.