PuCl{CoCp[OP(OEt)]}: transuranic elements entering the field of heterometallic molecular chemistry.

Recent advances enabled the discovery of heterometallic molecules for many metals: main group, d-block, lanthanides, and some actinides (U, Th). These complexes have at least two different metals joined by bridging ligands or by direct metal-metal bonding interactions. They are attractive because they can enable chemical cooperativity between metals from different parts of the periodic table.

Impact of Vertex Functionalization on Flexibility of Porous Organic Cages.

Efficient carbon capture requires engineered porous systems that selectively capture CO and have low energy regeneration pathways. Porous liquids (PLs), solvent-based systems containing permanent porosity through the incorporation of a porous host, increase the CO adsorption capacity. A proposed mechanism of PL regeneration is the application of isostatic pressure in which the dissolved nanoporous host is compressed to alter the stability of gases in the internal pore.

Photochemical separation of plutonium from uranium.

Plutonium-based technologies would benefit if chemical hazards for purifying plutonium were reduced. One critical processing step where improvements could be impactful is the adjustment of plutonium oxidation-states during separations. This transformation often requires addition of redox agents.

Oxidizing Americium(III) with Sodium Bismuthate in Acidic Aqueous Solutions.

Historic perspectives describing f-elements as being redox "inactive" are fading. Researchers continue to discover new oxidation states that are not as inaccessible as once assumed for actinides and lanthanides. Inspired by those contributions, we studied americium(III) oxidation in aqueous media under air using NaBiO.

Condition-Dependent Coordination and Peroxidase Activity of Hemin-Aβ Complexes.

The peroxidase activity of hemin-peptide complexes remains a potential factor in oxidative damage relevant to neurodegeneration. Here, we present the effect of temperature, ionic strength, and pH relevant to pathophysiological conditions on the dynamic equilibrium between high-spin and low-spin hemin-Aβ constructs. This influence on peroxidase activity was also demonstrated using 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) and dopamine (DA) oxidation rate analyses with increasing ratios of Aβ and Aβ (up to 100 equivalents).

Ratiometric Turn-On Fluorophore Displacement Ensembles for Nitroaromatic Explosives Detection.

There is a recognized need in the area of explosives detection for fluorescence-based sensing systems that are capable of not only producing a turn-on response but also generating a distinctive spectral signature for a given analyte. Here, we report several supramolecular ensembles displaying efficient fluorophore displacement that give rise to an increase in fluorescence intensity upon exposure to various nitroaromatic compounds. The synthetic supramolecular constructs in question consist of a tetrathiafulvalene (TTF)-based pyrrolic macrocycle, benzo-TTF-calix[4]pyrrole (Bz-TTF-C4P), and fluorescent dyes, monomeric or dimeric naphthalenediimide (NDI) and perylenediimide (PDI) derivatives, as well as chloride or hexafluorophosphate (PF) salts of rhodamine 6G (Rh-6G).

Amethyrin-type expanded porphyrins that display anti-aromatic character upon protonation.

The use of protonation to switch nonaromatic expanded porphyrins to their corresponding anti-aromatic forms has not been widely explored. Here, we show that free-base pyriamethyrin and dipyriamethyrin display nonaromatic character, as inferred from NMR spectroscopic analyses, their optical properties, and theoretical calculations. Addition of two protons extends the π - conjugation of these amethyrin analogues and yields formally anti-aromatic systems.

Synthesis and Characterization of a Binuclear Copper(II)-dipyriamethyrin Complex: [Cu(dipyriamethyrin)(μ-1,1-acetato)].

The reaction between dipyriamethyrin and copper(II) acetate [Cu(OAc)] afforded what is, to our knowledge, the first transition metal-dipyriamethyrin complex. Molecular and electronic characterization of this binuclear Cu(II) complex via EPR, UV-vis, and single crystal X-ray diffraction analysis revealed marked differences between the present constructs and previously reported binuclear copper(II) hexaphyrin species. UV-vis titration analyses provided evidence for a homotropic positive allosteric effect, wherein the binuclear species is formed without significant intermediacy of a monomeric complex.

Metallotexaphyrins as MRI-Active Catalytic Antioxidants for Neurodegenerative Disease: A Study on Alzheimer's Disease.

The complex etiology of neurodegeneration continues to stifle efforts to develop effective therapeutics. New agents elucidating key pathways causing neurodegeneration might serve to increase our understanding and potentially lead to improved treatments. Here, we demonstrate that a water-soluble manganese(II) texaphyrin (MMn) is a suitable magnetic resonance imaging (MRI) contrast agent for detecting larger amyloid beta constructs.

Reduced texaphyrin: A ratiometric optical sensor for heavy metals in aqueous solution.

We report here a water-soluble metal cation sensor system based on the as-prepared or reduced form of an expanded porphyrin, texaphyrin. Upon metal complexation, a change in the redox state of the ligand occurs that is accompanied by a color change from red to green. Although long employed for synthesis in organic media, we have now found that this complexation-driven redox behavior may be used to achieve the naked eye detectable colorimetric sensing of several number of less-common metal ions in aqueous media.

Correction: UO -mediated ring contraction of pyrihexaphyrin: synthesis of a contracted expanded porphyrin-uranyl complex.

[This corrects the article DOI: 10.1039/C9SC01593K.].

UO -mediated ring contraction of pyrihexaphyrin: synthesis of a contracted expanded porphyrin-uranyl complex.

A new mixed hexaphyrin, pyrihexaphyrin (0.1.0.

Porphyrinoid f-Element Complexes.

Porphyrin and related pyrrole-containing macrocycles, collectively porphyrinoids, are versatile ligands that allow access to a multitude of coordination modes. Judicious modification of the porphyrin core as well as the pendant substituents has extended the coordination chemistry of porphyrinoids to include systems that are able to stabilize f-block element complexes with possible utility. This review focuses on our group's efforts to prepare expanded porphyrin and porphyrinogen ligands that can serve as tools to study and apply f-element metal coordination chemistry: it covers the background of the topic, selected syntheses, and application of these species in the chemical and medical sciences.

Tetrathiafulvalene-calix[4]pyrrole: a versatile synthetic receptor for electron-deficient planar and spherical guests.

The first tetrakis-tetrathiafulvalene-calix[4]pyrrole (TTF-C[4]P) was reported in 2004. Early on it and related π-extended TTF-C[4]Ps were found to function as both anion receptors and as hosts for planar electron deficient neutral guests, including nitroaromatic explosives. Anion binding was found to occur with a 1 : 1 binding stoichiometry and to stabilise the cone C[4]P conformation, whereas planar electron deficient guests were bound in a cooperative 1 : 2 fashion to the 1,3-alternate conformer.