Jason Love

The University of Edinburgh | UoE · School of Chemistry

The simple diamide ligand L was previously shown to selectively precipitate gold from acidic solutions typical of e-waste leach streams, with precipitation of gallium, iron, tin, and platinum possible under more forcing conditions. Herein, we report direct competition experiments to afford the order of selectivity. Thermal analysis indicates that t...

The dissolution of elemental gold is a fundamental step in its recycling by hydrometallurgy but has a significant environmental impact due to the use of strong acids or highly toxic reagents. Herein, it is shown that mixtures of acetyl halides and hydrogen peroxide in alcohols promote the rapid room‐temperature dissolution of gold by halogenation t...

Improving actinide separations is key to reducing barriers to medical and industrial actinide isotope production and to addressing the challenges associated with the reprocessing of spent nuclear fuel. Here, we report the first example of a supramolecular anion recognition process that can achieve this goal. We have designed a preorganized triamido...

The development of inexpensive and effective catalysts for the epoxidation of olefins to epoxides, which are key commodities for the chemical industry, is a continuing challenge. In this context, we present a supramolecular solution with the development of new host‐guest assemblies of sulfate ions and amidoammonium receptor cations that, for the fi...

Professor Isabelle Billard, Professor Alexandre Chagnes, Dr Euan Doidge, Professor Jason Love and Professor Magdalena Regel-Rosocka, introduce this RSC Advances themed collection on metal extraction and recycling.

The recycling of metals from electronic waste (e‐waste) using efficient, selective, and sustainable processes is integral to circular economy and net‐zero aspirations. Herein, we report a new method for the selective precipitation of metals such as gold and copper that offsets the use of organic solvents that are traditionally employed in solvent e...

The recycling of metals from electronic waste (e‐waste) using efficient, selective, and sustainable processes is integral to circular economy and net‐zero aspirations. Herein, we report a new method for the selective precipitation of metals such as gold and copper that offsets the use of organic solvents that are traditionally employed in solvent e...

New thioetheramide ligands (L, PhS(CH2)nCONRR’) co-extract Pd(II) and Pt(IV) from acidic chloride solutions. The Pd is transferred to a water-immiscible phase as a [Pd(L)2Cl2] complex with thioether groups in the inner sphere whilst Pt is extracted in an outer-sphere assembly, [(LH)2·PtCl6], containing protonated reagent molecules LH⁺ that charge-b...

The uranyl complex UVIO2Cl(LMes) of the redox-active, acyclic dipyrrin-diimine anion LMes- [HLMes = 1,9-di-tert-butyl-imine-5-(mesityl)dipyrrin] is reported, and its redox property is explored and compared with that of the previously reported UVIO2Cl(LF) [HLF = 1,9-di-tert-butyl-imine-5-(pentafluorophenyl)dipyrrin] to understand the influence of th...

The Cover Feature shows that straightforward dissolution of noble metals such as gold and copper is important to their recycling. A combination of a chlorophosphorane and hydrogen peroxide in acetonitrile rapidly dissolves gold, copper, and palladium to produce chloridometalate complexes. This method was applied to the dissolution of electronic was...

The dissolution of elemental noble metals (NMs) such as gold, platinum, palladium, and copper is necessary for their recycling but carries a high environmental burden due to the use of strong acids and toxic reagents. Herein, a new approach was developed for the rapid dissolution of elemental NMs in organic solvents using mixtures of triphenylphosp...

Supramolecular chemical strategies for Rare Earth (RE) element separations are emerging which amplify the small changes in properties across the series to bias selectivity in extraction or precipitation. These advances are important as the REs are crucial to modern technologies yet their extraction, separation, and recycling using conventional tech...

RSC Advances is delighted to announce a new themed collection titled ‘Metal Extraction and Recycling’. This collection is Guest Edited by Professor Jason Love (University of Edinburgh), Professor Alexandre Chagnes (University of Lorraine), Professor Isabelle Billard (Université Grenoble Alpes), Professor Magdalena Regel-Rosocka (Poznan University o...

The uranyl complexes UO2(OAc)(L) and UO2Cl(L) of the redox-active, acyclic diamido-dipyrrin anion L- are reported and their redox properties explored. Because of the inert nature of the complexes toward hydrolysis and oxidation, synthesis of both the ligands and complexes was conducted under ambient conditions. Voltammetric, electron paramagnetic r...

Photocatalysis has proved its potential in cleaving the Cβ-O linkages between the natural aromatic units in lignin biomass and converting abundant lignin biomass to valuable aromatic monomer products. However, the slow reaction rate and low selectivity for aromatic monomers still hinder its future industrial implementation. To address these challen...

In the present investigation, the selective recovery of nickel from a leach solution of delaminated metal clads from obsolete mobile phone PCBs using the industrial reagent ACORGA M5640 has been studied. As a first step, copper is selectively separated from the mixed metal leach liquor by solvent extraction at pH 2, to leave a nickel-rich raffinate...

The efficient separation of metals from ores and secondary sources such as electronic waste is necessary to realising circularity in metal supply. Precipitation processes are increasingly popular and are reliant on designing and understanding chemical recognition to achieve selectivity. Here we show that a simple tertiary diamide precipitates gold...

While pure chemistry aims to enhance knowledge within the chemical sciences, applied chemistry exploits the principles and theories of chemistry to answer specific questions or solve real-world challenges [...]

Depleted uranium (DU) is a widely untapped resource, with ca. 1.5m tonnes stored globally in 2015 from nuclear power. The need to better understand the chemistry involved in its safe storage has contributed to a renaissance in the field of actinide chemistry, with uranium and its compounds experiencing a myriad of exciting recent developments.1 T...

Simple primary amides and amines have been shown to operate in tandem to synergistically transport both inner‐ and outer‐sphere rhodium chloridometalate complexes from aqueous hydrochloric acid into an organic phase in solvent extraction experiments. The complexes have been identified using a range of analytical, spectroscopic, crystallographic, an...

The sequential separation of base and precious metals from the end-of-life mobile phone printed circuit boards (PCBs) is a significant challenge for the development of recycling process that exhibit material circularity. In this contribution, a simple, eco-friendly, and efficient leaching process is developed for the dissolution of copper and nicke...

The separation and isolation of many of the platinum group metals (PGMs) is currently achieved commercially using solvent extraction processes. The extraction of rhodium is problematic however, as a variety of complexes of the form [RhCln(H2O)6‐n]⁽ⁿ⁻³⁾⁻ are found in hydrochloric acid, making it difficult to design a reagent that can extract all the...

The recycling of metals such as gold and copper from discarded end-of-life electronic waste (e-waste or WEEE) is an important aspect to the development of environmentally benign manufacturing processes that exhibit circularity in materials flow. Global e-waste production is increasing at a 3-5 % rate, so it is concerning that only 30 % is recycled...

A new constrained-cavity [1+1] Schiff-base dipyrrin macrocycle comprising an N4 donor-pocket has been synthesised by spontaneous oxidation and in-situ crystallisation. Access to Fe(II) and Zn(II) complexes is achieved by salt...

Titanium dioxide (TiO2) is one of the most promising photocatalytic materials, but its practical applications are always limited since it could only be excited in the UV range and has low photocatalytic efficiency due to its wide band gap and fast recombination rate. To overcome these problems, transition metals have been used as dopants to improve...

The separation of gallium from iron by solvent extraction from chloride media is challenging because the anionic chloridometalates, FeCl 4 − and GaCl 4 − , display similar chemical properties. However, we report here that the selective separation of gallium from iron in HCl solution can be achieved using the dual-purpose ionic liquid methyltrioctyl...

The rhenium complex, [K(DME)(18-c-6)][ReH4(Bpin)(η²-HBpin)(κ²-H2Bpin)] 1, comprising hydride and boron ligands only, has been synthesized by exhaustive deoxygenation of the commercially available perrhenate anion (ReO4⁻) with pinacol borane (HBpin). The structure of 1 was analysed by X-ray crystallography, NMR spectroscopy, and DFT calculations. Wh...

The oxo- and catecholate-bridged UIV/UIV Pacman complex [{(py)UIVOUIV(µ-O2C6H4)(py)}(LA)] A (LA = a macrocyclic “Pacman” ligand; anthracenylene hinge between N4-donor pockets, ethyl substituents on meso-carbon atom of each N4-donor pocket) featuring...

The mode of action of iron(III) uptake from sulfate solutions by the commercial extractant CYANEX®272, bis(2,4,4-trimethylpentyl)phosphinic acid, has been studied using conventional solvent extraction methods, together with ³¹P{¹ H} NMR spectroscopy, electrospray ionisation mass spectrometry, and DFT calculations that have not previously been used...

The recycling of tantalum (Ta) is becoming increasingly important due to the criticality of its supply from a conflict mineral. It is used extensively in modern electronics, such as in capacitors, and so electronic waste is a potentially valuable secondary source of this metal. However, the recycling of Ta is difficult, not least because of the cha...

Crystals of a Cu complex of the macrocyclic Schiff-base calixpyrrole or ‘Pacman’ ligand, Cu2(L), do not contain any solvent-accessible void space at ambient pressure, but adsorbs neon at 4.67 GPa,...

Rapid global technological development has led to the rising production of electronic waste that presents both challenges and opportunities in its recycling. In this review, we highlight the value of metal resources in the printed circuit boards (PCBs) commonly found in end-of-life electronics, the differences between primary (ore) mining applicati...

Deoxydehydration (DODH) is one of the most promising tools to reduce the oxygen content of biomass (sugars and polyols) and provide analogues of platform chemicals that are derived from fossil resources. This reaction converts a vicinal diol into an alkene and is typically catalyzed by high‐oxidation‐state metal‐oxo compounds in the presence of a s...

The uranyl(VI) ‘Pacman’ complex [(UO2)(py)(H2L)] A (L = polypyrrolic Schiff-base macrocycle) is reduced by Cp2Ti(η2-Me3SiC[triple bond, length as m-dash]CSiMe3) and [Cp2TiCl]2 to oxo-titanated uranyl(V) complexes [(py)(Cp2TiIIIOUO)(py)(H2L)] 1 and [(ClCp2TiIVOUO)(py)(H2L)] 2. Combination of ZrII and ZrIV synthons with A yields the first ZrIV–uranyl...

The uranyl ion, [UVIO2]2+, possesses rigorously trans, strongly covalent, and chemically robust U-oxo groups. However, through the use of anaerobic reaction techniques, both one- and two-electron reductive functionalization of the uranyl oxo groups has been discovered and developed. Prior to 2010, this unusual reactivity centered around the reducti...

The recycling of metals from end-of-life secondary sources such as electronic waste remains a significant environmental and technological challenge currently detrimental to the development of circular economies. The complex nature of electronic waste, containing a myriad of different elemental metals, means that sophisticated yet simple separation...

Current methods for the extraction of rhodium carry the highest carbon footprint and worst pollution metrics of all of the elements used in modern technological applications. Improving upon existing methods is made difficult by the limited understanding of the molecular-level chemistry occurring in extraction processes, particularly in the hydromet...

Controlled, photocatalytic C−H bond activations are key reactions in the toolkits of the modern synthetic chemist. While it is known that the uranyl(VI) ion, [UVIO2]²⁺, the environmentally dominant form of uranium, is photoactive, most literature examines its luminescent properties, neglecting its potential synthetic utility for photocatalytic C−H...

The reactions between alcohols and the tetranuclear ethyl-Zn complexes of an ortho-phenylene-bridged polypyrrole macrocycle, Zn 4 Et 4 (L ¹ ) 1 and the related anthracenyl-bridged macrocyclic complex, Zn 4 Et 4 (THF) 4 (L ² ) 2 have been studied. With long-chain alcohols such as n-hexanol, the clean formation of the tetranuclear hexoxide complex Zn...

The most common motif in uranium chemistry is the linear d0f0 uranyl ion [UO2]2+. The strong, covalent U=O bonds render the oxo groups poorly Lewis basic and unreactive, and its salts persistent environmental contaminants. However, using anaerobic techniques we have been able to reduce, reorganise, and functionalise one or both oxo groups for the f...

Professor Geoff Cloke FRS celebrates his 65th birthday in 2018. In a career spanning four decades, his research endeavours have accounted for some of the most innovative synthetic chemistry of the modern era, with his many publications describing truly exceptional compounds and experimental methods that portray a unique chemical imagination. In add...

Furan and thiophene diarylmethenes are potential redox-active ligands for metal centers that could be exploited in the development of nontraditional, stoichiometric, and catalytic redox reactions. As such, we describe here the selective meso-deprotonations of dithiophene, difuran, and diimine-difuran diarylmethanes to form the π-conjugated anions,...

While the recovery of rare earth elements (REEs) from aqueous solution by ionic liquids (ILs) has been well documented, the metal compounds that are formed in the organic phase remain poorly characterized. Using spectroscopic, analytical, and computational techniques, we provide detailed chemical analysis of the compounds formed in the organic phas...

The oxygenation of aliphatic and aromatic hydrocarbons using earth-abundant Fe and Cu catalysts and "green" oxidants such as hydrogen peroxide is becoming increasingly important to atom-economical chemical processing. In light of this, we describe that dinuclear CuII complexes of pyrrolic Schiff-base macrocycles, in combination with ferric chloride...

The use of amidoxime-functionalized polymer fibers as a sorbent for uranium has attracted recent interest for the extraction of uranium from seawater. Vanadium is one of the main competing ions for uranium sorption as V(V) species, however, vanadium is also present as V(IV) in seawater. In the present study, the interactions of V(IV) with amidoxime...

A new type of double uranium oxo cation [O–U–O–U–O] ⁴⁺ is prepared by selective oxygen-atom abstraction from macrocyclic uranyl complexes using either boranes or silanes.

A combination of mass spectrometry, DFT calculations and 31P{1H} NMR spectroscopy has been used to define the mode of action of the commercial cobalt extractant, bis(2,4,4-trimethylpentyl)phosphinic acid (CYANEX®272, L1H) in Co recovery. The nature of the Co(II)-complexes formed in the water-immiscible phase is determined largely by the propensity...

The controlled manipulation of the axial oxo and equatorial halide ligands in the uranyl dipyrrin complex, UO2Cl(L) allows the uranyl reduction potential to be shifted by 1.53 V into the range accessible to naturally occurring reductants that are present during uranium remediation and storage processes. Abstraction of the equatorial halide ligand t...

Simple ammonium and pyridinium perrhenate salts were evaluated as catalysts for the deoxydehydration (DODH) of diols into alkenes. Pyridinium perrhenates were found to be effective catalysts at much lower temperatures than those in previous reports, outperforming primary, secondary, and tertiary ammonium salts, while quaternary ammonium salts are e...

The first thorium(IV) and uranium(IV) hydrocarbyl complexes of a trans-calix[2]benzene[2]pyrrolide macrocycle can use ligand noninnocence to enable multiple C–H bond activation reactions at the metal. Both alkyl and alkynyl complexes supported by the L dianion and L–2H tetraanion are reported. The ThIV and UIV monoalkyl-ate complexes [M(L–2H)An(R)]...

Combining computational modeling with experimental measurements has revealed the self-assembly of nano-aggregate structures in the transfer of HCl and PtCl62– from an aqueous phase into toluene by the common industrial extractant tributyl phosphate (TBP). Molecular dynamics simulations have been coupled to analytical measurements to provide an atom...

We report the coordination chemistry of the tripodal tris[2-amido(2-pyridyl)ethyl]amine ligand, L, with thorium(iv) and uranium(iv). Using a salt-metathesis strategy from the potassium salt of this ligand, K3L, new actinide complexes were isolated, namely the dimeric thorium complex [ThCl(L)]2 (1) and the monomeric uranium complex UI(THF)(L) (2); u...

The reduction of UVI uranyl halides or amides by simple LnII or UIII salts forms highly symmetrical, linear, oxo-bridged trinuclear UV-LnIII-UV, LnIII-UIV-LnIII and UIV-UIV-UIV complexes or linear LnIII-UV polymers according to the stoichiometry and solvent choice. Reactions can be tuned to give one- or two-electron uranyl reduction. Some features...

The reduction of UVI uranyl halides or amides by simple LnII or UIII salts forms highly symmetrical, linear, oxo-bridged trinuclear UV-LnIII-UV, LnIII-UIV-LnIII and UIV-UIV-UIV complexes or linear LnIII-UV polymers according to the stoichiometry and solvent choice. Reactions can be tuned to give one- or two-electron uranyl reduction. Some features...

In this article we present the rational synthesis and full characterization of molecular Pd3-clusters sandwiched by imidazolium- and pyridinium-functionalized cycloheptatrienide ligands, of general formula [Pd3Br3(C7H6R)2]+. Starting from functionalized η3-cycloheptatrienide-Pd complexes, PdBr2(η3-C7H6R), a number of synthetic routes were tested an...

The synthesis, metalation, and redox properties of an acyclic bis(iminothienyl)methene L ⁻ are presented. This π‐conjugated anion displayed pronounced redox activity, undergoing facile one‐electron oxidation to the acyclic, metal‐free, neutral radical L . on reaction with FeBr 2 . In contrast, the reaction of L ⁻ with CuI formed the unique, neutral...

The simple perrhenate salt [N(hexyl)4][(ReO4)] acts as a catalyst for the reduction of organic carbonyls and carbon dioxide by primary and secondary hydrosilanes. In the case of CO2, this results in the formation of methanol equivalents via silylformate and silylacetal intermediates. Furthermore, the addition of alkylamines to the reaction mixture...

The synthesis, metalation, and redox properties of an acyclic bis(iminothienyl)methene (L) are presented. This pi-conjugated anion displayed pronounced redox activity, undergoing facile one-electron oxidation to the acyclic, metal-free, neutral radical on reaction with FeBr2. In contrast, the reaction of L with CuI formed the unique, neutral Cu2I2(...

The synthesis, metalation, and redox properties of an acyclic bis(iminothienyl)methene L ⁻ are presented. This π‐conjugated anion displayed pronounced redox activity, undergoing facile one‐electron oxidation to the acyclic, metal‐free, neutral radical L . on reaction with FeBr 2 . In contrast, the reaction of L ⁻ with CuI formed the unique, neutral...

The first use of a dinuclear UIII/UIII complex in the activation of small molecules is reported. The octadentate Schiff-base pyrrole, anthracene-hinged 'Pacman' ligand LA combines two strongly reducing UIII centres and three borohydride ligands in [M(THF)4][{U(BH4)}2(μ-BH4)(LA)(THF)2] 1-M, (M = Li, Na, K). The two borohydride ligands bound to urani...

The heterotetra- and bimetallic uranium(iv)-rhodium(i) complexes [U(IV)I2(μ-OAr(P)-1κ(1)O,2κ(1)P)2Rh(I)(μ-I)]2 (2) (Ar(P)O(-) = 2-(diphenylphosphino)-6-tert-butyl-4-methylphenoxide) and U(IV)I(μ-I)(μ-OAr(P)-1κ(1)O,2κ(1)P)3Rh(I) (3) were prepared by treatment of U(IV)I(OAr(P)-κ(2)O,P)3 (1) with rhodium(i) iodide olefin complexes. The reaction of 1 w...

An analysis of 552 structures of metal complexes of alkyl and arylphosphinates in the Cambridge Crystallographic Database shows that the phosphinate ligating group is remarkably versatile and is able to adopt ten different binding motifs in both mono- and polynuclear complexes in which an individual phosphinate group can bind to up to five metal at...

The possibility of recovering rare earth elements from solutions containing their chloridometalate anions [LnClx](x−3)− via the process: LnClx(x−3)− + (x − 3)Lorg + (x–3)H⁺ ⇌ [(LH)x−3LnClx]org has been tested using 2-(1,3-bis(hexylamino)-1,3-dioxopropan-2-yl)-4,6-di-tert-butylpyridine (PMA), tri-n-butylphosphate (TBP), and tri-n-octylamine (TOA), w...

Correction for ‘Inner-sphere vs. outer-sphere reduction of uranyl supported by a redox-active, donor-expanded dipyrrin’ by James R. Pankhurst et al., Chem. Sci., 2016, DOI: 10.1039/c6sc02912d.

The uranyl(VI) complex UO 2 Cl(L) of the redox-active, acyclic diimino-dipyrrin anion, L À is reported and its reaction with inner-and outer-sphere reductants studied. Voltammetric, EPR-spectroscopic and X-ray crystallographic studies show that chemical reduction by the outer-sphere reagent CoCp 2 initially reduces the ligand to a dipyrrin radical,...

Welcome to this themed issue of Dalton Transactions entitled “Reactions facilitated by ligand design”.

A dramatic difference in the ability of the reducing An(III) center in AnCp3 (An=U, Np, Pu; Cp=C5 H5 ) to oxo-bind and reduce the uranyl(VI) dication in the complex [(UO2 )(THF)(H2 L)] (L="Pacman" Schiff-base polypyrrolic macrocycle), is found and explained. These are the first selective functionalizations of the uranyl oxo by another actinide cati...

A dramatic difference in the ability of the reducing AnIII center in AnCp3 (An=U, Np, Pu; Cp=C5H5) to oxo-bind and reduce the uranyl(VI) dication in the complex [(UO2)(THF)(H2L)] (L=“Pacman” Schiff-base polypyrrolic macrocycle), is found and explained. These are the first selective functionalizations of the uranyl oxo by another actinide cation. At...

Waste electrical and electronic equipment (WEEE) such as mobile phones contains a plethora of metals of which gold is by far the most valuable. Herein a simple primary amide is described that achieves the selective separation of gold from a mixture of metals typically found in mobile phones by extraction into toluene from an aqueous HCl solution; u...

Waste electrical and electronic equipment (WEEE) such as mobile phones contains a plethora of metals of which gold is by far the most valuable. Herein a simple primary amide is described that achieves the selective separation of gold from a mixture of metals typically found in mobile phones by extraction into toluene from an aqueous HCl solution; u...

The computationally- and experimentally-determined molecular structures of a bis-uranyl(vi) complex of an expanded Schiff-base polypyrrolic macrocycle [(UO2)2(L)] are in close agreement only if the pyridine in the fifth equatorial donor site on the uranium is included in the calculations. The relativistic density functional theory (DFT) calculation...

Heterodinuclear uranyl/group 14 complexes of the aryl- and anthracenyl-linked Schiff-base macrocyclic ligands L(Me) and L(A) were synthesised by reaction of UO2(H2L) with M{N(SiMe3)2}2 (M = Ge, Sn, Pb). For complexes of the anthracenyl-linked ligand (L(A)) the group 14 metal sits out of the N4-donor plane by up to 0.7 Å resulting in relatively shor...

Extraction and binding studies of [PtCl6](2-) are reported for 24 mono-, bi-, and tripodal extractants containing tris(2-aminoethyl)amine (TREN) or tris(3-aminopropyl)amine (TRPN) scaffolds. These reagents are designed to recognize the outer coordination sphere of [PtCl6](2-) and to show selectivity over chloride anion under acidic conditions. Extr...

Studies of transuranic organometallic complexes provide a particularly valuable insight into covalent contributions to the metal-ligand bonding, in which the subtle differences between the transuranium actinide ions and their lighter lanthanide counterparts are of fundamental importance for the effective remediation of nuclear waste. Unlike the org...

Hydrophobic imidazolium-based ionic liquids (IL) act as catalysts for the epoxidation of unfunctionalized olefins in water using hydrogen peroxide as oxidant. Although the catalysts are insoluble in both the substrate and in water, surprisingly, they are very well soluble in aqueous H2 O2 solution, owing to perrhenate-H2 O2 interactions. Even more...

Alkyl-substituted phenolic pyrazoles such as 4-methyl-2-[5-(n-octyl)-1H-pyrazol-3-yl]phenol (L2H) are shown to function as Cu-extractants, having similar strength and selectivity over Fe(iii) to 5-nonylsalicylaldoxime which is a component of the commercially used ACORGA® solvent extraction reagents. Substitution in the phenol ring of the new extrac...

Mono- and dinuclear calcium complexes of the Schiff-base macrocycles H4L have been prepared and characterized spectroscopically and crystallographically. In the formation of Ca(THF)2(H2L(1)), Ca2(THF)2(μ-THF)(L(1)), and Ca2(THF)4(L(2)), the ligand framework adopts a bowl-shaped conformation instead of the conventional wedge, Pacman-shaped structure...

The effect of pressure on the intranuclear M···M separation and intermolecular secondary interactions in the dinuclear chromium Pacman complex [Cr2(L)](C6H6) was evaluated because this compound contains both a short Cr···Cr separation and an exogenously bound molecule of benzene in the solid state. The electronic structure of [Cr2(L)] was determine...

High anion selectivity for PtCl6(2-) over Cl(-) is shown by a series of amidoamines, R(1)R(2)NCOCH2CH2NR(3)R(4) (L1 with R(1) = R(4) = benzyl and R(2) = R(3) = phenyl and L3 with R(1) = H, R(2) = 2-ethylhexyl, R(3) = phenyl and R(4) = methyl), and amidoethers, R(1)R(2)NCOCH2CH2OR(3) (L5 with R(1) = H, R(2) = 2-ethylhexyl and R(3) = phenyl), which p...

Copper complexes of the phenolic oxime family of ligands (3-X-salicylaldoximes) are used extensively as metal solvent extractants. Incorporation of electronegative substituents in the 3-position, ortho to the phenol group, can be used to buttress the interligand H-bonding, leading to an enhancement in extractant strength. However, investigation of...

Uranyl complexes of a large, compartmental N8-macrocycle adopt a rigid, "Pacman" geometry that stabilizes the U(V) oxidation state and promotes chemistry at a single uranyl oxo-group. We present here new and straightforward routes to singly reduced and oxo-silylated uranyl Pacman complexes and propose mechanisms that account for the product formati...

Reactions between the uranyl(vi) Pacman complex [(UO2)(py)(H2L)] of the Schiff-base polypyrrolic macrocycle L and Tebbe's reagent or DIBAL result in the first selective reductive functionalisation of the uranyl oxo by Al to form [(py)(R2AlOUO)(py)(H2L)] (R = Me or (i)Bu). The clean displacement of the oxo-coordinated Al(iii) by Group 1 cations has...

The design of ligands that can act as platforms for the controlled, “bottom-up” synthesis of transition-metal clusters is a promising approach to accessing enzymatic mimics and new small-molecule reaction chemistry. This approach is exemplified here through the coordination chemistry of two compartmental Schiff-base calixpyrroles (H4L) that usually...

Organic-phase supramolecular ion pair (SIP) host–guest assemblies of perrhenate anions (ReO4−) with ammonium amide receptor cations are reported. These compounds act as catalysts for the epoxidation of alkenes by aqueous hydrogen peroxide under biphasic conditions and can be recycled several times with no loss in activity.

U(III) complexes of the conformationally flexible, small-cavity macrocycle trans-calix[2]benzene[2]pyrrolide (L)2–, [U(L)X] (X = O-2,6-tBu2C6H3, N(SiMe3)2), have been synthesized from [U(L)BH4] and structurally characterized. These complexes show binding of the U(III) center in the bis(arene) pocket of the macrocycle, which flexes to accommodate th...

Welcome to this Dalton Transactions themed issue including papers from Dalton Discussion 14 – Advancing the chemistry of the f-elements .

Oxidation of acyclic Schiff-base dipyrromethanes cleanly results in dipyrrins, whereas the macrocyclic 'Pacman' analogues either decompose or form new dinuclear copper(ii) complexes that are inert to ligand oxidation; the unhindered hydrogen substituent at the meso-carbon allows new structural motifs to form.