Ross S Forgan

University of Glasgow | UofG · School of Chemistry

3D printing techniques allow the laboratory-scale design and production of reactionware tailored to specific experimental requirements. To increase the range and versatility of reactionware devices, sealed, monolithic reactors suitable for use in hydrothermal synthesis have been digitally designed and realized. The fabrication process allows the in...

The research reported herein is based upon work supported under the auspices of an international collaboration supported in the US by the National Science Foundation under grant CHE-0924620 and in the UK by the Engineering and Physical Research Council under grant EP/H003517/1. The authors would like to thank Prof. Michael O′Keeffe, Arizona State U...

The binding of alkali and alkaline earth metal cations by macrocyclic and diazamacrobicyclic polyethers, composed of ordered arrays of hard oxygen (and nitrogen) donor atoms, underpinned the development of host-guest supramolecular chemistry in the 1970s and 1980s. The arrangement of -OCCO- and -OCCN- chelating units in these preorganized receptors...

The efficient capture and storage of gaseous CO(2) is a pressing environmental problem. Although porous metal-organic frameworks (MOFs) have been shown to be very effective at adsorbing CO(2) selectively by dint of dipole-quadruple interactions and/or ligation to open metal sites, the gas is not usually trapped covalently. Furthermore, the vast maj...

The role of covalent, coordinative, and supramolecular interactions utilized by chemists and biochemists, when they are assembling molecular knots and links, are presented. The Trefoil Knot comprises a simple overhand knot where the two ends have been connected and can exist in left-handed and right-handed forms. A molecular Trefoil Knot displays i...

Navigating the reaction parameter space can pose challenges, especially considering the exponential growth in the number of parameters even in seemingly straightforward chemical reactions. Consequently, recent research efforts have been increasingly dedicated to the development of computational tools aimed at facilitating the exploration process. H...

Metal-organic frameworks (MOFs) are currently widely investigated for a number of potential biomedicinal applications, with particular focus on nanoscale drug delivery. Nanomedicine in general comes with specific challenges to ensure reproducibility of results, including batch-to-batch variations in ostensibly the same nanomaterial, differences in...

Two-dimensional metal–organic nanosheets (MONs) have emerged as attractive alternatives to their three-dimensional metal–organic framework (MOF) counterparts for heterogeneous catalysis due to their greater external surface areas and higher accessibility of catalytically active sites. Zr MONs are particularly prized because of their chemical stabil...

Postsynthetic modification of metal-organic frameworks (MOFs) has proven to be a hugely powerful tool to tune physical properties and introduce functionality, by exploiting reactive sites on both the MOF linkers and their inorganic secondary building units (SBUs), and so has facilitated a wide range of applications. Studies into the reactivity of M...

Careful control of synthetic conditions can enhance the structural diversity of metal-organic frameworks (MOFs) within individual metal-linker combinations. Herein, we show that hcp topology MOFs of both Zr(IV) and Hf(IV),...

The chemistries that can be incorporated within melt-quenched zeolitic imidazolate framework (ZIF) glasses are currently limited. Here we describe the preparation of a previously unknown purine-containing ZIF which we name...

Conditions have been identified in which phenolic aldoximes and ketoximes of the types used in commercial solvent extraction processes can be doubly deprotonated and generate polynuclear Cu complexes with lower extractant:Cu molar ratios than those found in commercial operations. Electrospray mass spectrometry has provided an insight into the solut...

Nanoporous Materials In article number 2201502, David Fairen‐Jimenez and co‐workers conduct a round‐robin exercise by providing 18 already‐measured adsorption isotherms to sixty‐one labs and show that the reproducibility of the Brunauer–Emmett–Teller (BET) area determination in micro‐ and mesoporous materials remains a largely ignored issue. To sol...

Codelivery of chemotherapeutics via nanomaterials has attracted much attention over the last decades due to improved drug delivery to tumor tissues, decreased systemic effects, and increased therapeutic efficacies. High porosities, large pore volumes and surface areas, and tunable structures have positioned metal–organic frameworks (MOFs) as promis...

Porosity and surface area analysis play a prominent role in modern materials science. At the heart of this sits the Brunauer–Emmett–Teller (BET) theory, which has been a remarkably successful contribution to the field of materials science. The BET method was developed in the 1930s for open surfaces but is now the most widely used metric for the est...

The influence of composition and textural characteristics of a family of ultra-small isoreticular UiO-type metal-organic frameworks (MOFs) with different functionalized and extended linkers on their catalytic performance is evaluated. Two direct amide bond formations across four different substrates (benzylamine + phenylacetic acid and aniline + fo...

This book provides a contemporary research-led overview of the applications of inorganic materials in biomedicine. It begins with a short introduction summarising key concepts in inorganic materials (layered materials, framework materials etc.), and explaining the need for new materials in medicine. It then discusses the key areas in which inorgani...

The synthesis of phase pure metal-organic frameworks (MOFs) - network solids of metal clusters connected by organic linkers - is often complicated by the possibility of forming multiple diverse phases from one metal-ligand combination. For example, there are at least six Fe-terephthalate MOFs reported to date, with many examples in the literature o...

To achieve optimal performance in gas storage and delivery applications, metal-organic frameworks (MOFs) must combine high gravimetric and volumetric capacities. One potential route to balancing high pore volume with suitable crystal density is interpenetration, where identical nets sit within the void space of one another. Herein, we report an int...

Porosity and surface area analysis play a prominent role in modern materials science, where 123 their determination spans the fields of natural sciences, engineering, geology and medical 124 research. At the heart of this sits the Brunauer-Emmett-Teller (BET) theory,[1] which has been 125 a remarkably successful contribution to the field of materia...

Nanoscale metal-organic frameworks (NMOFs) are an interesting and unique class of hybrid porous materials constructed by the self-assembly of metal ions/clusters with organic linkers. The high storage capacities, facile synthesis, easy surface functionalization, diverse compositions and excellent biocompatibilities of NMOFs have made them promising...

The Sc(III) MOF-type MFM-300(Sc) is demonstrated in this study to be stable under physiological conditions (PBS), biocompatible (to human skin cells) and an efficient drug carrier for the long-term controlled release (through human skin) of antioxidant ferulate. MFM-300(Sc) also preserves the antioxidant pharmacological effects of ferulate while en...

Conformational changes of linker units in metal‐organic frameworks (MOFs) are often responsible for gate‐opening phenomena in selective gas adsorption and stimuli‐responsive optical and electrical sensing behaviour. Herein, we show that pressure‐induced bathochromic shifts in both fluorescence emission and UV/Vis absorption spectra of a two‐fold in...

Mitochondria play a key role in oncogenesis and constitute one of the most important targets for cancer treatments. Although the most effective way to deliver drugs to mitochondria is by covalently linking them to a lipophilic cation, the in vivo delivery of free drugs still constitutes a critical bottleneck. Herein, we report the design of a mitoc...

Druckinduzierte bathochrome Verschiebungen in den Fluoreszenzemissions‐ und UV/Vis‐Absorptionsspektren eines zweifach verzahnten Hf‐MOF werden durch Rotation des zentralen Phenylrings des Linkers ausgelöst. Einkristall‐Röntgenbeugung wurde bei Drücken bis 2.1 GPa vorgenommen; die Ergebnisse ermöglichen die Korrelation der Linkerrotation mit der Emi...

Metal–organic frameworks (MOFs) are emerging as leading candidates for nanoscale drug delivery, as a consequence of their high drug capacities, ease of functionality, and the ability to carefully engineer key physical properties. Despite many anticancer treatment regimens consisting of a cocktail of different drugs, examples of delivery of multiple...

Multivariate Modulation: Die Eingliederung multipler Modulatoren in den Selbstorganisationsprozess von MOFs liefert UiO‐66‐Nanopartikel mit drei Arten eingelagerter Wirkstoffe in Defektstellen. Die Struktur bleibt dabei genügend porös, um nach der Synthese ein viertes, selektivitätsverstärkendes Tumortherapeutikum zu speichern. Abstract Metal–orga...

Modifying the outer surfaces of metal-organic frameworks (MOFs) has received considerably less attention than functionalization of the bulk, despite the range of physical and chemical properties that can be tuned by controlling MOF surface chemistry. In this Frontier article, we summarise developments over the last five years in both functionalizin...

Phase control in the self-assembly of metal-organic frameworks (MOFs) is often a case of trial and error; judicious control over a number of synthetic variables is required to select the desired topology and control features such as interpenetration and defectivity. Herein, we present a comprehensive investigation of self-assembly in the Fe-bipheny...

Nanoparticulate metal-organic frameworks (MOFs) have the requisite high storage capacities, tailorable structures, ease of functionalisation, and excellent biocompatibilities for application as nanoscale drug delivery devices (DDSs). Zirconium MOFs in particular combine optimal stability towards hydrolysis and postsynthetic modification with low to...

Metal-organic frameworks (MOFs)—network structures built from metal ions or clusters and connecting organic ligands—are typically synthesized by solvothermal self-assembly. For transition metal based MOFs, structural predictability is facilitated by control over coordination geometries and linker connectivity under the principles of isoreticular sy...

One of the most important non-radiative relaxation processes that limits the quantum yield of a fluorophore is related to aggregation of the molecules in the solid-state causing excimer quenching. To limit this quenching mechanism, the fluorophore can be contained within a well-ordered 3D system that minimises aggregation through rigid bonds and sp...

Phase control in the self-assembly of metal-organic frameworks (MOFs) – materials wherein organic ligands connect metal ions or clusters into network solids with potential porosity – is often a case of trial and error. Judicious control over a number of synthetic variables is required to select for the desired topology and control features such as...

Metal-organic frameworks (MOFs), network structures wherein metal ions or clusters link organic ligands into porous materials, are being actively researched as nanoscale drug delivery devices (DDSs) as they offer tuneable structures with high cargo loading that can easily be further functionalized for targeting and enhanced physiological stability....

A new family of supramolecular hydrogelators are introduced in which self‐sorting and co‐assembly can be utilised in the tuneability of the mechanical properties of the materials, a property closely tied to the nanostructure of the gel network. The in situ reactivity of the components of the gelators allows for system chemistry concepts to be appli...

A critical bottleneck for the use of metal-organic frameworks (MOFs) as drug delivery systems has been allowing them to reach their intracellular targets without being degraded in the acidic environment of the lysosomes. Cells take up particles by endocytosis through multiple biochemical pathways, and the fate of these particles depends on these ro...

Ammonia absorption has been investigated in metal-organic frameworks (UiO-67, HKUST-1 and CPO-27-Co) using custom-built apparatus that allows simultaneous neutron powder diffraction (NPD), microwave dielectric characterisation and out-gas mass spectroscopy of solid-state materials during ammonia adsorption. Deuterated ammonia was flowed through the...

Dual delivery of dichloroacetate and 5-fluorouracil from Zr MOFs into cancer cells is found to enhance in vitro cytotoxicity. Tuning particle size and, more significantly, surface chemistry, further improves cytotoxicity...

The high drug loading and excellent biocompatibilities of metal-organic frameworks (MOFs) have led to their application as drug delivery systems (DDSs). Nanoparticle surface chemistry dominates both biostability and dispersion of DDSs while governing their interactions with biological systems, cellular and/or tissue targeting, and cellular internal...

Interpenetration in metal-organic frameworks (MOFs), where multiple nets of metal ions or clusters linked by organic ligands are nested within each other’s pore spaces, affects important physical properties such as stability and gas uptake, and can be controlled through ligand sterics and modifying synthetic conditions. Herein, we extend the use of...

A critical bottleneck for the use of metal-organic frameworks (MOFs) as drug delivery systems has been allowing them to reach their intracellular targets without being degraded in the acidic environment of the lysosomes. Cells take up particles by endocytosis through multiple biochemical pathways, and the fate of these particles depends on these ro...

Introduction of hydrogen bond functionality into metal-organic frameworks can enhance guest binding and activation, but a combination of linker flexibility and interligand hydrogen bonding often results in the generation of unwanted structures where the functionality is masked. Herein, we describe the self-assembly of three materials, where Cd²⁺, C...

Advances in nanotechnology offer the possibility of tailored delivery of therapeutics with real-time imaging of disease. In this issue of Chem, Steunou and co-workers amalgamate the powerful MRI properties of ultra-small paramagnetic iron oxides with the excellent drug-delivery capabilities of metal-organic frameworks to produce theranostic nanopar...

The incorporation of polyoxometalates (POMs) as structural units into ordered porous constructs such as metal-organic frameworks (MOFs) is desirable for a range of applications where intrinsic properties inherited from both the MOF and POM are utilised, including catalysis and magnetic data storage. The controlled self-assembly of targeted MOF topo...

Using artificial agents to deliver drugs selectively to sites of disease while protecting them from metabolism and clearance offers potential routes to new treatments. Porous metal-organic frameworks (MOFs) have emerged as potential candidates because they offer high storage capacities and easy clearance after delivery. We report on a method that c...

The high storage capacities and excellent biocompatibilities of metal-organic frameworks (MOFs) have made them emerging candidates as drug-delivery vectors. Incorporation of surface functionality is a route to enhanced properties, and here we report on a surface-modification procedure—click modulation— that controls their size and surface chemistry...

Many of the desirable properties of metal-organic frameworks (MOFs) can be tuned by chemical functionalization of the organic ligands that connect their metal clusters into multidimensional network solids. When these linker molecules are intrinsically fluorescent, they can pass on this property to the resultant MOF, potentially generating solid-sta...

Salicylaldehyde hydrazones are weaker copper extractants than their oxime derivatives, which are used in hydrometallurgical processes to recover ∼20% of the world's copper. Their strength, based on the extraction equilibrium constant Ke, can be increased by nearly three orders of magnitude by incorporating electron-withdrawing or hydrogen-bond acce...

We have used a family of Zr-based metal-organic frameworks (MOFs) with different functionalized (bromo, nitro and amino) and extended linkers for drug delivery. We loaded the materials with the fluorescent model molecule calcein and the anticancer drug α-cyano-4-hydroxycinnamic acid (α-CHC), and consequently performed a mechanical amorphization pro...

Metal-organic frameworks (MOFs) have been in the spotlight for a number of years due to their chemical and topological versatility. As MOF research has progressed, highly functionalised materials have become desirable for specific applications, and in many cases the limitations of direct synthesis have been realised. This has resulted in the search...

Supplementary

Metal-organic frameworks (MOFs) containing Zr(IV) -based secondary building units (SBUs), as in the UiO-66 series, are receiving widespread research interest due to their enhanced chemical and mechanical stabilities. We report the synthesis and extensive characterisation, as both bulk microcrystalline and single crystal forms, of extended UiO-66 (Z...

A multidisciplinary experiment for advanced undergraduate students has been developed in the context of extractive metallurgy. The experiment serves as a model of an important modern industrial process that combines aspects of organic/inorganic synthesis and analysis. Students are tasked to prepare a salicylaldoxime ligand and samples of the corres...

The synthesis of zirconium and hafnium metal-organic frameworks (MOFs) often relies on coordination modulation – the addition of competing monotopic modulators to reaction mixtures – to reproducibly generate highly crystalline material. Typically, large excesses of monocarboxylic acids such as formic, acetic and benzoic acid are applied, but access...

Whilst many metal–organic frameworks possess the chemical stability needed to be used as functional materials, they often lack the physical strength required for industrial applications. Herein, we have investigated the mechanical properties of two UiO-topology Zr-MOFs, the planar UiO-67 ([Zr6O4(OH)4(bpdc)6], bpdc: 4,4′-biphenyl dicarboxylate) and...

We have used a family of Zr-based metal-organic frameworks (MOFs) with different functionalized (bromo, nitro and amino) and extended linkers for drug delivery. We loaded the materials with the fluorescent model molecule calcein and the anticancer drug α-cyano-4-hydroxycinnamic acid (α-CHC), and consequently performed a mechanical amorphization pro...

A new member of the UiO-66 series of zirconium metal-organic frameworks (MOFs) is reported, and the postsynthetic bromination of its integral alkene moeities in a single-crystal to single-crystal manner is fully characterised. Nanoindentation is used to probe the bromination of unsaturated carbon-carbon bonds, in it and an analogous Zr MOF, which l...

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...

The properties of metal-organic frameworks (MOFs) can be tuned by post-synthetic modification (PSM) to introduce specific functionalities after their synthesis. Typically, PSM is carried out on pendant functional groups or through metal/ligand exchange, preserving the structure of the MOF. We report herein the bromination of integral alkyne units i...

Metal-organic frameworks (MOFs)—porous materials composed of organic linkers connected by metal ion or metal cluster joints—are increasingly being investigated as intravenous drug delivery vectors, as a consequence of their high molecular storage capacities, ease of functionalization, amenability to formulation, and, most importantly, the potential...

3D printing techniques allow the laboratory-scale design and production of reactionware tailored to specific experimental requirements. To increase the range and versatility of reactionware devices, sealed, monolithic reactors suitable for use in hydrothermal synthesis have been digitally designed and realized. The fabrication process allows the in...

Metal-organic frameworks (MOFs) have received particular attention over the last 20 years as a result of their attractive properties offering potential applications in a number of areas. Typically, these characteristics are tuned by functionalisation of the bulk of the MOF material itself. This Feature Article focuses instead on modification of MOF...

Metal-organic frameworks (MOFs) are a well-studied class of porous materials with the potential to be used in many applications such as gas storage and catalysis.[1] UiO-67 (UiO = University of Oslo), a MOF built from zirconium oxide units connected with 4,4-biphenyldicarboxylate (BDC) linkers, forms a face centred cubic structure. Zirconium has a...

We report the synthesis of three donor–acceptor azido-functionalised catenanes, wherein the asymmetric positioning of the azide group on one or two of the ring components renders its resident macrocycle constitutionally asymmetric, and so it acts as an oriented ring. As a consequence, the analyses of (i) a monoazido[2]catenane, (ii) a monoazido[3]c...

The self-assembly of two topological isomers of a handcuff catenane has been achieved by utilizing the template-directed synthesis between the π-electron-rich bis-1,5-dioxynaphtho[50]crown-14 and the precursors to two fused π-electron-deficient cyclobis(paraquat-p-phenylene) cyclophanes. Characterization of the product using 1H NMR spectroscopy and...

The conformational flexibility and programmed assembly of a dumbbell-shaped polyoxometalate-organic hybrid molecule comprising two Dawson-type polyoxometalates linked by a 2,2'-bipyridine unit which can be coordinate to metal ions, in this case of Zn2+, is described. SAXS, UV/Vis, and NMR spectroscopic techniques confirm that the hybrid molecules e...

Two are better than one: The diazaperopyrenium dication acts as both a viologen-like electron-poor and an electron-rich guest, resulting in the formation of a 1:2 complex with cucurbit[8]uril. This chameleonic binding facilitates deaggregation of the dications from aqueous solutions, leading to an increase in the fluorescence quantum yield of the d...

A donor–acceptor [3]catenane incorporating two cyclobis(paraquat-p-phenylene) rings linked together by a dinaphtho[50]crown-14 macrocycle possesses a π-electron-deficient pocket. Contrary to expectation, negligible binding of a hexaethylene glycol chain interrupted in its midriff by a π-electron-rich 1,5-dioxynaphthalene unit was observed in aceton...

A trans isomer of a figure-of-eight (Fo8) compound was prepared from an electron-withdrawing cyclobis(paraquat-p-phenylene) derivative carrying trans-disposed azide functions between its two phenylene rings. Copper(I)-catalyzed azide-alkyne cycloadditions with a bispropargyl derivative of a polyether chain, interrupted in its midriff by an electron...

The chemistry of mechanically interlocked molecules (MIMs), in which two or more covalently linked components are held together by mechanical bonds, has led to the coining of the term mechanostereochemistry to describe a new field of chemistry that embraces many aspects of MIMs, including their syntheses, properties, topologies where relevant and f...

Starting from a chiral building block--α-cyclodextrin--and rubidium salts, the crystallization of a complex of chiral helices, which constitute a "green" porous coordination polymer, has been realized. Cyclodextrin molecules coordinated by rubidium ions form porous, infinitely long left-handed helical channels, interdigitated with each other. A the...

The self-assembly of three donor-acceptor ring-in-ring complexes, prepared from the π-electron-deficient tetracationic cyclophane, cyclobis(paraquat-4,4'-biphenylene), and three large π-electron-rich crown ethers (each 50-membered rings) containing dioxynaphthalene (DNP) and tetrathiafulvalene (TTF) units in pairs (DNP/DNP, DNP/TTF and TTF/TTF), is...

The intermolecular template-directed synthesis, separation and characterisation of two constitutional isomers that are self-complexing donor-acceptor [1]rotaxanes has been achieved by click chemistry, starting from a π-electron deficient tetracationic cyclophane containing two azide functions and a π-electron rich 1,5-dioxynaphthalene-containing po...

A series of 3-substituted salicylaldoximes has been used to demonstrate the importance of outer-sphere interactions on the efficacy of solvent extractants that are used to produce approximately one-quarter of the world's copper. The distribution coefficient for extraction of copper by 5-tert-butyl-3-X-salicylaldoximes (X = H, Me, (t)Bu, NO(2), Cl,...

Two donor-acceptor [3]catenanes-composed of a tetracationic molecular square, cyclobis(paraquat-4,4'-biphenylene), as the π-electron deficient ring and either two tetrathiafulvalene (TTF) and 1,5-dioxynaphthalene (DNP) containing macrocycles or two TTF-butadiyne-containing macrocycles as the π-electron rich components-have been investigated in orde...

Alkanediamines serve as neutral guests for the recently discovered host pillar[5]arene. The proposed [2]pseudorotaxane nature of the superstructure of the 1:1 host-guest complexes is supported by the template-directed synthesis of a related [2]rotaxane. A synthetic route to monofunctional pillar[5]arenes has also been developed, allowing for the cr...

Stamp of approval: Wet stamping allows metal-organic framework (MOF) crystals to be imprinted with micropatterns of various organic chemicals. Printing the MOFs with photochromic molecules and pH indicators generates stimuli-responsive micropatterns which change their appearance upon contact with specific chemicals (see picture), thus reporting the...

This paper reports the synthesis of sulphate extractants, N,N′-bis-(2-dibutylamino-ethyl)-isophthalamide (1), pyridine-2,6-dicarboxylic acid bis-[(2-dibutylamino-ethyl)-amide] (2) and 3,4-diphenyl-1H-pyrrole-2,5-dicarboxylic acid bis-[(2-dibutylamino-ethyl)-amide] (3), and demonstrates that, in combination with a commercially available oxime extrac...

Essbare MOFs stehen auf der Speisekarte, wenn der Koch seine kulinarische Kreation präsentiert. J. F. Stoddart, O. M. Yaghi et al. stellen in der Zuschrift auf S. 8812 ff. die Synthese Metall-organischer Grüste (MOFs) ausschließlich aus Ingredientien mit Lebensmittelqualität vor: γ-Cyclodextrin, Alkalimetallsalze, Wasser und Alkohol. Diese erneuerb...

The dynamic solution equilibria between molecular Borromean rings (BRs) and Solomon knots (SKs), assembled from transition metal-templated macrocycles, consisting of exo-bidentate bipyridyl and endo-tridentate diiminopyridyl ligands, have been examined with respect to the choice of the metal template and reaction conditions employed in the synthesi...

Two [3]catenane 'molecular flasks' have been designed to create stabilized, redox-controlled tetrathiafulvalene (TTF) dimers, enabling their spectrophotometric and structural properties to be probed in detail. The mechanically interlocked framework of the [3]catenanes creates the ideal arrangement and ultrahigh local concentration for the encircled...

A strategic modification to the corner ligands in Pd(II)-containing, electron-poor cyclophanes has profound repercussions for their assemblies with electron-rich aromatic crown ethers in both the solid and solution states; the formation of ring-in-ring complexes can override competing [3]catenane production on masking the hydrogen bond donor capabi...

Ligand-ligand interactions in the outer coordination sphere make an important contribution to the effects of 3-substituents on the stabilities of anionic Cu(II) salicylaldoximato complexes [CuL(L-H)](-). When substituents contain a different number of bonds the interpretation of CID tandem mass spectrometry must take into account the ability of ion...

3-Dialkylaminomethyl substituted salicylaldoximes are efficient metal salt extractants, and, in contrast to related "salen"-based reagents, are sufficiently stable to acid hydrolysis to allow commercial application in base metal recovery. Crystal structures show that metal salts are bound by a zwitterionic form of the reagents, with copper(II) nitr...

A previously unseen coordination mode is reported for (salicylaldoxime)copper complexes utilising a linked zwitterionic NO22– donor set. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)

3-Fluoro-salicylaldoxime, C(7)H(6)FNO(2), unlike many salicylaldoxime derivatives, forms a crystal structure containing hydrogen-bonded chains rather than centrosymmetric hydrogen-bonded ring motifs. Each chain inter-acts with two chains above and two chains below via π-π stacking contacts [shortest centroid-centroid distance = 3.295 (1) Å]. This s...

The assembly of molecular Borromean Rings from con-stitutionally independent rings in a stepwise manner depends on the preparation of robust "ring-in-ring" complexes. The π-electron rich macrocycle bis-1,5-dinaphtho[50]crown-14 (1) is shown to form a donor-acceptor ring-in-ring complex with the π-electron poor cyclo-phane cyclobis(paraquat-4,4'-bip...