Surface modification with multiphilic ligands at detectable well defined active positions of nano-object of giant wheel shaped molybdenum blue showing third-order nonlinear optical properties

Robotic exploration of amino-acid functionalised molybdenum blue polyoxometalate nanoclusters

A robotic platform was employed to investigate the synthetic conditions for the assembly of molybdenum blue (MB) polyoxometalates in a large chemical space that included concentrations of reactants, the amount of reducing agent, solution pH etc. Four different solid phases of {Mo154} MB clusters were identified and crystallographically explored, demonstrating the robotic platform's strength in targeted exploration.

Lanthanides Singing the Blues: Their Fascinating Role in the Assembly of Gigantic Molybdenum Blue Wheels

Molybdenum blues (MBs) are a distinct class of polyoxometalates, exhibiting versatile/impressive architectures and high structural flexibility. In acidified and reduced aqueous environments, isopolymolybdates generate precisely organizable building blocks, which enable unique nanoscopic molecular systems (MBs) to be constructed and further fine-tuned by hetero elements such as lanthanide (Ln) ions. This Review discusses wheel-shaped MB-based structure types with strong emphasis on the ∼30 Ln-containing MBs as of August 2021, which include both organically hybridized and nonhybridized structures synthesized to date. The spotlight is thereby put on the lanthanide ions and ligand types, which are crucial for the resulting Ln-patterns and alterations in the gigantic structures. Several critical steps and reaction conditions in their synthesis are highlighted, as well as appropriate methods to investigate them both in solid state and in solution. The final section addresses the homogeneous/heterogeneous catalytic, molecular recognition and separation properties of wheel-shaped Ln-MBs, emphasizing their inimitable behavior and encouraging their application in these areas.

Stereoselective Assembly of Gigantic Chiral Molybdenum Blue Wheels Using Lanthanide Ions and Amino Acids

The synthesis of chiral polyoxometalates (POMs) is a challenge because of the difficulty to induce the formation of intrinsically chiral metal-oxo frameworks. Herein we report the stereoselective synthesis of a series of gigantic chiral Mo Blue (MB) POM clusters 1-5 that are formed by exploiting the synergy between coordinating lanthanides ions as symmetry breakers to produce MBs with chiral frameworks decorated with amino acids ligands; these promote the selective formation of enantiopure MBs. All the compounds share the same framework archetype, based on {Mo124Ce4}, which forms an intrinsically chiral Δ or Λ configurations, controlled by the configurations of functionalized chiral amino acids. The chirality and stability of 1-5 in solution are confirmed by circular dichroism, 1H NMR, and electrospray ion mobility-mass spectrometry studies. In addition, the framework of the {Mo124Ce4} MB not only behaves as a host able to trap a chiral {Mo8} cluster that is not accessible by traditional synthesis but also promotes the transformation of tryptophan to kynurenine in situ. This work demonstrates the potential and applicability of our synthetic strategy to produce gigantic chiral POM clusters capable of host-guest chemistry and selective synthetic transformations.

Exploring the Molecular Growth of Two Gigantic Half-Closed Polyoxometalate Clusters {Mo180 } and {Mo130 Ce6 }

Understanding the process of the self‐assembly of gigantic polyoxometalates and their subsequent molecular growth, by the addition of capping moieties onto the oxo‐frameworks, is critical for the development of the designed assembly of complex high‐nuclearity cluster species, yet such processes remain far from being understood. Herein we describe the molecular growth from {Mo₁₅₀} and {Mo₁₂₀Ce₆} to afford two half‐closed gigantic molybdenum blue clusters {Mo₁₈₀} (1) and {Mo₁₃₀Ce₆} (2), respectively. Compound 1 features a hat‐shaped structure with the parent wheel‐shaped {Mo₁₅₀} being capped by a {Mo₃₀} unit on one side. Similarly, 2 exhibits an elliptical lanthanide‐doped wheel {Mo₁₂₀Ce₆} that is sealed by a {Mo₁₀} unit on one side. Moreover, the observation of the parent uncapped {Mo₁₅₀} and {Mo₁₂₀Ce₆} clusters as minor products during the synthesis of 1 and 2 strongly suggests that the molecular growth process can be initialized from {Mo₁₅₀} and {Mo₁₂₀Ce₆} in solution, respectively.

A survey of the different roles of polyoxometalates in their interaction with amino acids, peptides and proteins

This perspective provides a comprehensive description of the different roles of POMs in their interaction with relevant biological molecules.