Configurational Isomerism in Bimetallic Decametalates.

In this work, we report on the development of a computational algorithm that explores the configurational isomer space of bimetallic decametalates with general formula MxM10-x'O28q. For being a natural number in the range of 0 to 10, the algorithm identifies 318 unique configurational isomers. The algorithm is used to generate mixed molybdenum(VI)-vanadium(V) systems MoxV10-xO288- for x=0,1,2, and 3 that are of experimental relevance.

Knowledge Engineering in Chemistry: From Expert Systems to Agents of Creation.

Passing knowledge from human to human is a natural process that has continued since the beginning of humankind. Over the past few decades, we have witnessed that knowledge is no longer passed only between humans but also from humans to machines. The latter form of knowledge transfer represents a cornerstone in artificial intelligence (AI) and lays the foundation for knowledge engineering (KE).

Polyoxoplatinates as covalently dynamic electron sponges and molecular electronics materials.

In organic systems, dynamic covalent chemistry provides an adaptive approach (, "covalent dynamics") where thermodynamic equilibria are used to tailor structural and electronic changes in molecular assemblies. The covalent dynamics finds utility in the design of novel self-healing materials, sensors, and actuators. Herein, using density functional theory (DFT) we explore the structural, electronic and transport properties of the Pt-based polyoxometalate (POM) [Pt O(SO)] and its derivatives.

Composition-driven archetype dynamics in polyoxovanadates.

Molecular metal oxides often adopt common structural frameworks ( archetypes), many of them boasting impressive structural robustness and stability. However, the ability to adapt and to undergo transformations between different structural archetypes is a desirable material design feature offering applicability in different environments. Using systems thinking approach that integrates synthetic, analytical and computational techniques, we explore the transformations governing the chemistry of polyoxovanadates (POVs) constructed of arsenate and vanadate building units.

Automated Rational Design of Metal-Organic Polyhedra.

Metal-organic polyhedra (MOPs) are hybrid organic-inorganic nanomolecules, whose rational design depends on harmonious consideration of chemical complementarity and spatial compatibility between two or more types of chemical building units (CBUs). In this work, we apply knowledge engineering technology to automate the derivation of MOP formulations based on existing knowledge. For this purpose we have (i) curated relevant MOP and CBU data; (ii) developed an assembly model concept that embeds rules in the MOP construction; (iii) developed an OntoMOPs ontology that defines MOPs and their key properties; (iv) input agents that populate The World Avatar (TWA) knowledge graph; and (v) input agents that, using information from TWA, derive a list of new constructible MOPs.

Metal-metal bonds in polyoxometalate chemistry.

Half a century ago, F. Albert Cotton emphasized the relevance of metal-metal bonding in the constitution of cluster materials. Based on his description, nanoscale polyoxometalates (POMs) normally would not be regarded as cluster materials.

Hybrid polyoxometalates as post-functionalization platforms: from fundamentals to emerging applications.

Polyoxometalates (POMs) represent an important group of metal-oxo nanoclusters, typically comprised of early transition metals in high oxidation states (mainly V, Mo and W). Many plenary POMs exhibit good pH, solvent, thermal and redox stability, which makes them attractive components for the design of covalently integrated hybrid organic-inorganic molecules, herein referred to as hybrid-POMs. Until now, thousands of organic hybrid-POMs have been reported; however, only a small fraction can be further functionalized using other organic molecules or metal cations.

Keggin Structure, Quō Vādis?

Working under the supervisor of William Lawrence Bragg at the University of Manchester and being under the direct personal and scientific influence by Linus Pauling, Dr. James Fargher Keggin some 85 years ago published a highly unique discovery-the structure of phosphotungstic acid (Nature 1933, 131, 908-909). This structure sparked the reports of other related polyanions from Keggin's contemporaries, marking the true beginnings of structural polyoxometalate chemistry.

Superactivity of MOF-808 toward Peptide Bond Hydrolysis.

MOF-808, a Zr(IV)-based metal-organic framework, has been proven to be a very effective heterogeneous catalyst for the hydrolysis of the peptide bond in a wide range of peptides and in hen egg white lysozyme protein. The kinetic experiments with a series of Gly-X dipeptides with varying nature of amino acid side chain have shown that MOF-808 exhibits selectivity depending on the size and chemical nature of the X side chain. Dipeptides with smaller or hydrophilic residues were hydrolyzed faster than those with bulky and hydrophobic residues that lack electron rich functionalities which could engage in favorable intermolecular interactions with the btc linkers.

Configurational Isomerism in Polyoxovanadates.

A water-soluble derivative of the polyoxovanadate {V E O } (E=semimetal) archetype enables the study of cluster shell rearrangements driven by supramolecular interactions. A reaction unique to E=Sb, induced exclusively by ligand metathesis in peripheral [Ni(ethylenediamine) ] counterions, results in the formation of the metastable α * configurational isomer of the {V Sb O } cluster type. Contrary to all other polyoxovanadate shell architectures, this isomer comprises an inward-oriented vanadyl group and is ca.

The Cu(i)-catalysed Huisgen 1,3-dipolar cycloaddition route to (bio-)organic functionalisation of polyoxovanadates.

The [VO{(OCH)CCHOCHC[triple bond, length as m-dash]CH}] with two terminal alkyne functionalities exhibits excellent reactivity towards (bio-)organic azides. The designed synthetic protocol for the generation of triazol-modified Lindqvist hexavanadates grants access to bio-"clicked" polyoxometalates with spectroscopically detectable V nuclei.

Breaking the Gordian Knot in the Structural Chemistry of Polyoxometalates: Copper(II)-Oxo/Hydroxo Clusters.

This Concept article provides insights into the molecular design and construction aspects of polyoxocuprates (POCus), an emerging class of polyoxometalate (POM)-like architectures featuring low-to-high nuclearity copper(II)-oxo/hydroxo skeletons. POCus have been identified to adopt the structural principles of classical POMs consisting of early transition metals. Their potential to afford motifs of the noble-metal-based POMs is exploited.

Chiral Dodecanuclear Palladium(II) Thio Cluster: Synthesis, Structure, and Formation Mechanism Explored by ESI-MS and DFT Calculations.

The chiral dodecanuclear palladium(II) thio cluster LaPd12(C3H5NO2S)3(C3H6NO2S)21 (1) was prepared by reacting l-cysteine (l-Cys) with PdCl2 and La2O3 in aqueous solution under carefully controlled conditions. Compound 1 was structurally characterized by single-crystal XRD, TGA, IR, UV-vis, (13)C NMR, and CD spectroscopy. Insight into the dimerization process of 1 was obtained by ESI-MS and DFT calculations.

Rotational Isomerism, Electronic Structures, and Basicity Properties of "Fully-Reduced" V14-type Heteropolyoxovanadates.

We investigated computationally the α-, γ-, and β-isomeric structures, relative stabilities, and the electronic and basicity properties of magnetic [V(IV)14E8O50](12-) (hereafter referred to as {V14E8}) heteropolyoxovanadates (heteroPOVs) and their heavier chalcogenide-substituted [V(IV)14E8O42X8](12-) ({V14E8X8}) derivatives for E = Si(IV), Ge(IV), and Sn(IV) and X = S, Se, and Te. We used density functional theory (DFT) with scalar relativistic corrections in combination with the conductor-like screening model of solvation. The main purpose of this investigation is to introduce the structure-property relations in heteroPOVs as well as to assist the synthesis and molecular deposition of these molecular vanadium-oxide spin clusters on surfaces.

Platinum-Containing Polyoxometalates: syn- and anti-[Pt(II)2(α-PW11O39)2](10-) and Formation of the Metal-Metal-Bonded di-Pt(III) Derivatives.

The first examples of dimeric, di-Pt(II) -containing heteropolytungstates are reported. The two isomeric di-platinum(II)-containing 22-tungsto-2-phosphates [anti-Pt(II)2(α-PW11O39)2](10-) (1 a) and [syn-Pt(II)2(α-PW11O39)2](10-) (2 a) were synthesized in aqueous pH 3.5 medium using one-pot procedures.

The polyoxo-22-palladate(ii), [Na2PdO12(As(V)O4)15(As(V)O3OH)](25-) .

The polyoxo-22-palladate [Na2PdO12(As(V)O4)15(As(V)O3OH)](25-) (1), which represents a novel polyoxo-noble-metalate structural type, was synthesized by reaction of Pd(2+) and AsO4(3-) ions in aqueous solution. Polyanion 1 comprises two {NaPd11} units linked by two arsenate bridges, and hence represents the first example of a defect, monolacunary {Pd11} polyoxopalladate nanocube with arsenate capping groups. The title polyanion was characterized in the solid state as well as by theoretical calculations.

The mixed gold-palladium polyoxo-noble-metalate [NaAu(III)4Pd(II)8O8(AsO4)8](11-).

The first fully inorganic, discrete gold-palladium-oxo complex [NaAu(III) 4 Pd(II) 8 O8 (AsO4 )8 ](11-) has been synthesized in aqueous medium. The combination of single-crystal XRD, elemental analysis, mass spectrometry, and DFT calculations allowed establishing the structure and composition of the novel polyanion, and UV/Vis studies suggest that it is stable in neutral aqueous media.