Modulating the Supramolecular Assembly of α-Cyclodextrin and Anderson-type Polyoxometalate through Covalent Modifications.

A series of unprecedented supramolecular complexes of covalently modified Anderson-type polyoxometalates (POMs) and α-cyclodextrins (α-CDs) have been obtained and characterized in solid state by single-crystal X-ray diffraction, and in aqueous solution using various techniques including H DOSY NMR, 2D NOESY H NMR, isothermal titration calorimetry (ITC), and electrospray ionization time-of-flight mass spectroscopy (ESI-TOF-MS). It has been demonstrated that the supramolecular assembly process could be modulated by different covalent modification modes of the Anderson POMs, giving rise to a new type of POM/α-CD complexes featuring organic-inorganic pseudo-rotaxane structures, which are in good contrast to those of POM/γ-CD complexes of poly-rotaxane structures. Moreover, it is delighted to find that these pseudo-rotaxanes of POM/α-CD complexes exhibit stable chirality in aqueous solution, which has not been accomplished in previously reported POM/CD assemblies.

Polyoxometalate-Surfactant Assemblies: Responsiveness to Orthogonal Stimuli.

Integrating different types of supramolecular interactions opens the possibility to generate nanoparticle surfactants (NPSs) at the liquid-liquid interface that are responsive to multiple stimuli. Here we develop a covalently modified polyoxometalate/β-cyclodextrin (POM/β-CD) organic-inorganic hybrid, consisting of a negatively charged POM cluster with β-CD host groups. The POM/β-CD hybrid can be dispersed in water and interacts at a water/oil interface with ligands dissolved in an oil phase through electrostatic or host-guest interactions, thereby generating POM-surfactants (POMSs) having pH, redox, and guest-competitive responsiveness, respectively.

Elucidating the paramagnetic interactions of an inorganic-organic hybrid radical-functionalized Mn-Anderson cluster.

A family of six polyoxometalate-based magnetic compounds were synthesized by anchoring N-oxide type TEMPO radicals onto an Anderson type polyoxometalate cluster. The complexes were structurally characterised by single crystal X-ray diffraction and the intramolecular paramagnetic interactions between TEMPO radicals and Mn ions of the resulting hybrids were investigated in detail by electron paramagnetic resonance and the Evans NMR method.

Structural Phase Transitions of a Molecular Metal Oxide.

The structural phase of a metal oxide changes with temperature and pressure. During phase transitions, component ions move in multidimensional metal-oxygen networks. Such macroscopic structural events are robust to changes in particle size, even at scales of around 10 nm, and size effects limiting these transitions are particularly important in, for example, high-density memory applications of ferroelectrics.

Integrated Synthesis of Gold Nanoparticles Coated with Polyoxometalate Clusters.

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 AuNO(PMe) 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.

A multi-species comparison of selective placement patterns of ramets in invasive alien and native clonal plants to light, soil nutrient and water heterogeneity.

A worth noticing pattern in current invasive biology is the clonal ability of many of the world's worst invasive plants. Selective placement of ramets (i.e.

Synthesis, structural characterization and fluorescence enhancement of chromophore-modified polyoxometalates.

Intramolecular charge transfers between π-conjugated molecules and polyoxometalate (POM) clusters have been observed in donor-acceptor systems based on organic donors and inorganic POM acceptors, which unfortunately results in a general quenching of the chromophore luminescence. The development of POM-chromophore dyads that are capable of tackling the quenching process and enhancing the fluorescence intensity of such systems remains a highly challenging area of study. A family of organic-inorganic polyoxometalate View Article and Find Full Text PDF

Digital Control of Multistep Hydrothermal Synthesis by Using 3D Printed Reactionware for the Synthesis of Metal-Organic Frameworks.

Hydrothermal-synthesis-based reactions are normally single step owing to the difficulty of manipulating reaction mixtures at high temperatures and pressures. Herein we demonstrate a simple, cheap, and modular approach to the design reactors consisting of partitioned chambers, to achieve multi-step synthesis under hydrothermal conditions, in digitally defined reactionware produced by 3D printing. This approach increases the number of steps that can be performed sequentially and allows an increase in the options available for the control of hydrothermal reactions.

3D printing of versatile reactionware for chemical synthesis.

In recent decades, 3D printing (also known as additive manufacturing) techniques have moved beyond their traditional applications in the fields of industrial manufacturing and prototyping to increasingly find roles in scientific research contexts, such as synthetic chemistry. We present a general approach for the production of bespoke chemical reactors, termed reactionware, using two different approaches to extrusion-based 3D printing. This protocol describes the printing of an inert polypropylene (PP) architecture with the concurrent printing of soft material catalyst composites, using two different 3D printer setups.

Step-by-step covalent modification of Cr-templated Anderson-type polyoxometalates.

A series of tripodal alcohols substituted Anderson-type polyoxometalates (POMs) including mono-substituted (compounds and ), asymmetrical bi-substituted (compound ), and symmetrical bi-substituted ones (compounds and ) have been synthesized under hydrothermal conditions using a pre-designed step-by-step strategy, and compounds , and have been fully characterized by single-crystal X-ray diffraction, ESI-MS, and elemental analysis.