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Novel complexes {[Dy(LN6en)(OAc)2](NO3)}·2H2O (1·2H2O) and {[Dy(LN6prop)(OAc)2](NO3)}·CHCl3 (2·CHCl3), containing partially flexible symmetric N6 macrocycles, are reported. We explore the influence of the spacer length between two symmetrical N3 rigid moieties of the ligand on their structural, magnetic, and luminescence properties. Crystallographic analysis reveals the presence of Dy3+ ions in distorted tetradecahedral (1·2H2O) or bicapped square antiprism (2·CHCl3) environments. This underscores the increased flexibility of the LN6prop ligand, resulting in greater distortion of the N6 macrocycle plane. Both complexes exhibit single-molecule magnet behaviour under an optimal field of 2000 Oe, with 2·CHCl3 displaying the highest Ueff value of 127 K, despite its less planar N6 macrocycle. Luminescence measurements indicate that the ratio between the integrated intensity of the ligands and that of the the Dy3+ 4F9/2 → 6H13/2 transition can define secondary luminescent thermometers. Maximum relative thermal sensitivity values of 2.3 (1·2H2O) and 5.1% K−1 (2·CHCl3) are achieved. Furthermore, deconvolution of the 4F9/2 → 6H15/2 transition in 2·CHCl3 supports the previous determination of the energy barrier for magnetic relaxation. This permits the demonstration of the first example of a Dy3+ primary luminescent thermometer based on two thermally coupled Kramer's doublets of the 4F9/2 level. Remarkably, 2·CHCl3 is also the first self-calibrated luminescent thermometer with magnetic relaxation operating within the 86–211 K range, showcasing its potential in precise temperature sensing applications

In this paper, the lanthanoid complexes of N5 and N6 macrocycle ligands, without pendant arms or additional heteroatoms, are surveyed. This review covers the period from 2015 to the current date, since in 2014 Schiff base macrocyclic ligands incorporating the pyridine moiety, and their complexes, were revised, and in 2015 the chemistry of pentaaza macrocycle ligands with rare earth metals was also summarized. Porphyrin and phthalocyanine ligands are not included in this review, which primarily focuses on complexes with Schiff bases and amines without pendant arms or any additional donor other than nitrogen. The synthetic methods, structural characterization, based on single X-ray crystal data, and properties of the lanthanoid complexes, with special attention to magneto-structural correlations, are presented herein.

The ligand design factors that may influence the isolation of metallosupramolecular helicates or mesocates still deserve to be investigated. In this sense, dinuclear nickel(II), copper(II) and zinc(II) compounds were obtained by electrochemical synthesis using a family of five Schiff base ligands, H2Ln (n = 1–5), derived from bisphenylmethane and functionalized with bulky tert-butyl groups in the periphery and ethyl groups in the spacer. Six of the new complexes were characterized by X-ray crystallography, thus demonstrating that the helicate structure is predominant in the solid state. 1H NMR studies were performed for the zinc complexes to analyze if the helical architecture of the metal complexes is retained in solution. These studies reveal that the presence of a tert-butyl group in the ortho position with respect to the OH group is an essential factor identified for the existence of a helicate conformation in solution

This study addresses the fabrication of microporous plasmonic nanocomposites (NCs) by using plasmonic nanoparticles (i.e., gold bipyramids, AuB) as seeds to grow microporous shells, specifically, metal–organic frameworks (MOF) PCN-224 of increasing thickness from 69 to 138 nm. This method is based on using a previously synthesized Zr6-oxo cluster and unfolds at room temperature. Notably, it is demonstrated that the concentration of the AuB seeds determines both the yield of NCs and the resultant thickness of the PCN-224 shell, illustrating the seeded growth mechanism. Furthermore, it is found that the thermoplasmonic response of the NCs is dominated by the thickness of the microporous shell, with thicker shells having enhanced thermal confinement properties than thinner ones. As a proof of concept, the NCs are loaded with cresyl violet (CV), a lysosomal fluorescent marker. This serves to demonstrate the thermoplasmonic-induced intracellular release of CV by the photostimulation of the AuB's plasmonic near-infrared (NIR) band. Moreover, the NCs display exceptional efficacy as photodynamic agents when photostimulated at the PCN-224's Soret band. In summary, this study offers a facile, efficient, and reproducible methodology for the fabrication of NCs with a controlled geometry while unlocking new possibilities in the field of nanoMOFs as multifunctional theranostic probes.

Intravenous administration of fibrinolytic drugs, such as recombinant tissue plasminogen activator (rtPA) is the standard treatment of acute thrombotic diseases. However, current fibrinolytics exhibit limited clinical efficacy because of their short plasma half-lives and risk of hemorrhagic transformations. Platelet membrane-based nanocarriers have received increasing attention for ischemic stroke therapies, as they have natural thrombus-targeting activity, can prolong half-life of the fibrinolytic therapy, and reduce side effects. In this study we have gone further in developing platelet-derived nanocarriers (defined as cellsomes) to encapsulate and protect rtPA from degradation. Following lyophilization and characterization, their formulation properties, biocompatibility, therapeutic effect, and risk of hemorrhages were later investigated in a thromboembolic model of stroke in mice.

In the biological milieu, nanoparticles (NPs) interact with different biomolecules, particularly proteins, leading to the formation of an interfacial corona, which gives rise to a new biological identity affecting NP biodistribution, cytotoxicity and biological fate. The surface coating of NPs plays a key role in regulating such biocorona formation and composition. We here investigated the interactions between bovine serum albumin (BSA) and bovine fibrinogen (FIB) with gold nanorods (Au NRs) bearing different surface coatings (cetyltrimethylammonium bromide, CTAB, and carboxylic acid and amine-terminated polyethylene glycols (PEGs). It was revealed that CTAB-coated NPs interact with both proteins with high affinity (ca. 108-109 M−1) whereas for PEG ones the extent of protein binding decreases thanks to the stealth properties of PEG, but a protein corona is still formed, with binding affinities between 104-106 M−1. In addition, present results indicated that thicknesses of protein coronas and the aggregation behavior of AuNPs were closely related to their surface properties and protein structure. We also found that BSA and FIB underwent different conformational changes upon adsorption depending on the surface-modified Au NRs. Hence, these findings offered important insights into the essence of the interactions between NPs and proteins toward the development of safe and effective nanomaterials

The lack of selectivity toward the oxygen reduction reaction (ORR) in metal nanoparticles can be linked to the generation of intermediates. This constitutes a crucial constraint on the performance of specific electrochemical devices, such as fuel cells and metal–air batteries. To boost selectivity of metal nanoparticles, a novel methodology that harnesses the unique electrocatalytic properties of polyoxometalates (POM) to scavenge undesired intermediates of the ORR (such as HO2−) promoting selectivity is proposed. It involves the covalent functionalization of metal nanoparticle's surface with an electrochemically active capping layer containing a new sulfur-functionalized vanadium-based POM (AuNP@POM). To demonstrate this approach, preformed thiolate Au(111) nanoparticles with a relatively poor ORR selectivity are chosen. The dispersion of AuNP@POM on the surface of carbon nanofibers (CNF) enhances oxygen diffusion, and therefore the ORR activity. The resulting electrocatalyst (AuNP@POM/CNF) exhibits superior stability against impurities like methanol and a higher pH tolerance range compared to the standard commercial Pt/C. The work demonstrates for the first time, the use of a POM-based electrochemically active capping layer to switch on the selectivity of poorly selective gold nanoparticles, offering a promising avenue for the preparation of electrocatalyst materials with improved selectivity, performance, and stability for ORR-based devices.

The influence of the solvent in the reaction of dysprosium(III) chloride hydrate with the N3O2 ligand H2L (2,6-bis(2-hydroxyphenyliminomethyl)pyridine) was studied To this end, the new mononuclear chloride complex [Dy(L)Cl(H2O)2] (1) was isolated in absolute ethanol as solvent, without any evidence of the hydrolysis of the ligand. This clearly contrasts with previous results, where a similar reaction in methanol proceeds with the partial hydrolysis of the Schiff base, and the formation of a new hemiacetal donor to yield [Dy(HL’)2)][Dy(L)(Cl2)] (H2L’ = (6-(2- hydroxyphenyliminomethyl)-2-methoxyhydroxymethyl)pyridine). The single crystal X-ray structure of the chloride complex 1 shows that the DyIII ion is octacoordinated in a highly distorted N3O4Cl environment between triangular dodecahedral and biaugmented trigonal prisms. The full magnetic characterisation of 1 shows that it presents field-induced single ion magnet behaviour, with a thermal energy barrier Ueff of 113.5 K, which is the highest among dysprosium complexes derived from H2L.

The chemistry of CuI and CuII is rich, and these oxidation states can be converted into each other by using quite mild or more strong oxidizing or reducing agents, depending on the starting materials and reaction conditions. Thus, this work describes an easy way to obtain yellow copper(I) oxide from copper(II) sulfate, using hydroxylamine hydrochloride as a reductant. In addition, the aqueous chemistry of CuII is very abundant, and in basic media, it perfectly exemplifies the chemistry of any transition metal having amphoteric hydroxides. For this purpose, copper(II) hydroxide is prepared from copper(II) sulfate by addition of basic medium. The insoluble amphoteric hydroxide reacts again with a solution of sodium hydroxide to form the corresponding water-soluble sodium tetrahydroxocuprate(II). Finally, an experiment is carried out to demonstrate the instability of CuI in aqueous acid medium, which disproportionates to form Cu0 and the corresponding water-soluble copper(II) salt. This set of experiments has been designed to be performed in a single 3–4 h laboratory session, and it has been tested several times with second-year undergraduate chemistry students at the University of Santiago de Compostela (Spain).

Catalytic water splitting is a promising approach to produce clean hydrogen fuel from renewable energy sources. However, developing hybrid heterostructures capable of efficiently breaking down water into its constituent elements, hydrogen, and oxygen, presents a considerable challenge. In this study, a novel hierarchical POM/Pd/MoS2 hybrid heterostructure, composed of sheets of MoS2 modified with Pd nanoparticles and combined with a cobalt-based polyoxometalate (POM), serving as bifunctional catalyst for water splitting is reported. Through a synergistic synthetic approach, MoS2, acting as a reducing agent, triggers the nucleation and growth of Pd nanoparticles, which, in turn, serve as anchoring sites for the polymerization of the cobalt-based POM into fibers. POM/Pd/MoS2 hybrid exhibits an enhanced oxygen evolution reaction (OER) activity, comparable to the benchmark catalysts Ir/C and IrO2/C in alkaline media, being its hydrogen evolution reaction (HER) activity similar to the activated Pd/MoS2 hybrid. The intriguing electrocatalytic capability of the resulting material for producing hydrogen and oxygen through electrochemical means arises from the enhanced charge storage capacity and conductivity of MoS2, the multi-electron transfer facilitated by the POM, and the high electrocatalytic activity of the metals

The development of systems that can be switched between states with different thermal conductivities is one of the current challenges in materials science. Despite their enormous diversity and chemical richness, molecular materials have been only scarcely explored in this regard. Here, we report a reversible, light-triggered thermal conductivity switching of ≈30–40% in mesophases of pure 4,4′-dialkyloxy-3-methylazobenzene. By doping a liquid crystal matrix with the azobenzene molecules, reversible and bidirectional switching of the thermal conductivity can be achieved by UV/Vis-light irradiation. Given the enormous variety of photoactive molecules and chemically compatible liquid crystal mesophases, this approach opens unforeseen possibilities for developing effective thermal switches based on molecular materials

A surface-engineered cell-derived nanocarrier was developed for efficient cytosolic delivery of encapsulated biologically active molecules inside living cells. Thus, a combination of aromatic-labeled and cationic lipids, instrumental in providing fusogenic properties, was intercalated into the biomimetic shell of self-assembled nanocarriers formed from cell membrane extracts. The nanocarriers were loaded, as a proof of concept, with either bisbenzimide molecules, a fluorescently labeled dextran polymer, the bicyclic heptapeptide phalloidin, fluorescently labeled polystyrene nanoparticles or a ribonucleoprotein complex (Cas9/sgRNA). The demonstrated nanocarrieŕs fusogenic behavior relies on the fusogen-like properties imparted by the intercalated exogenous lipids, which allows for circumventing lysosomal storage, thereby leading to efficient delivery into the cytosolic milieu where cargo regains function

Non-symmetric poly(diphenylacetylene)s (PDPAs) show a strong relationship between the size of the macromolecules and their electronic circular dichroism (ECD) spectra. Thus, polymers and oligomers of PDPAs with the same screw sense excess show opposite ECD spectra. This is due to the complex nature of the ECD spectra, where the main electronic transitions depend on the degree of polymerization (DP)

Metal–organic frameworks (MOFs) are extremely versatile materials, which serve to create platforms with exceptional porosity and specific reactivities. The production of MOFs at the nanoscale (NMOFs) offers the possibility of creating innovative materials for bioapplications as long as they maintain the properties of their larger counterparts. Due to their inherent chemical versatility, synthetic methods to produce them at the nanoscale can be combined with inorganic nanoparticles (NPs) to create nanocomposites (NCs) with one-of-a-kind features. These systems can be remotely controlled and can catalyze abiotic reactions in living cells, which have the potential to stimulate further research on these nanocomposites as tools for advanced therapies

Since the discovery of Quantum Dots (QDs) by Alexey I. Ekimov in 1981, the interest of researchers in that particular type of nanomaterials (NMs) with unique optical and electrical properties has been increasing year by year. Thus, since 2009, the number of scientific articles published on this topic has not been less than a thousand a year. The increasing use of QDs due to their biomedical, pharmaceutical, biological, photovoltaics or computing applications, as well as many other high-tech uses such as for displays and solid-state lighting (SSL), has given rise to a considerable number of studies about its potential toxicity. However, there are a really low number of reported studies on the detection and quantification of QDs, and these include ICP–MS and electrochemical analysis, which are the most common quantification techniques employed for this purpose. The knowledge of chemical phenomena occurring on the surface of QDs is crucial for understanding the interactions of QDs with species dissolved in the dispersion medium, while it paves the way for a widespread use of chemosensors to facilitate its detection. Keeping in mind both human health and environmental risks of QDs as well as the scarcity of analytical techniques and methodological approaches for their detection, the adaptation of existing techniques and methods used with other NMs appears necessary. In order to provide a multidisciplinary perspective on QD detection, this review focused on three interrelated key aspects of QDs: properties, surface chemistry and detection

We studied the interaction of Cu2+ ions and CuO nanoparticles with the fluorescent Schiff base ligand H3L, which derives from the condensation of 4-formyl-3-hydroxybenzoic acid with N-(2-aminobenzyl)-5-(dimethylamino)naphthalene-1-sulfonamide (DsA). A detailed assignment of the most significant bands of the electronic and infrared spectra of H3L and DsA was performed using DFT methods, based on both crystal structures. The affinity of H3L to react with Cu2+ ions in solution (KB = 9.01 103 L mol-1) is similar to that found for the Cu2+ ions present on the surface of CuO NPs (KB = 9.84 103 L mol-1). Fluorescence spectroscopic measurements suggest five binding sites for H3L on the surface of the CuO NPs used. The µ-XRF analysis indicates that a polycrystalline sample of CuO-H3L NPs contains 15:1 Cu:S molar ratio (CuO:H3L). ATR-FTIR spectroscopy, supported by DFT calculations, showed that the HL2- (as a phenolate and sulfonamide anion) is coordinated to superficial Cu2+ ions of the CuO NPs through their azomethine, sulphonamide, and phenolic groups. A solution of H3L (126 ppb) shows sensitive responses to CuO NPs, with a limit of detection (LOD) of 330 ppb. The working range for detection of CuO NPs with [H3L] = 126 ppb was 1.1-9.5 ppm. Common metal ions in water, such as Na+, K+, Mg2+, Ca2+, Fe3+, and Al3+ species, do not interfere significantly with the detection of CuO NPs.

We report two different approaches to isolate neutral and cationic mesocate-type metallosupramolecular archi- tectures derived from coinage monovalent ions. For this purpose, we use a thiocarbohydrazone ligand, H2L (1), conveniently tuned with bulky phosphine groups to stabilize the MI ions and prevent ligand crossing to achieve the selective formation of mesocates. The neutral complexes [Cu2(HL)2] (2), [Ag2(HL)2] (3), and [Au2(HL)2] (4) were prepared by an electrochemical method, while the cationic complexes [Cu2(H2L)2](PF6)2 (5), [Cu2(H2L)2](BF4)2 (6), [Ag2(H2L)2](PF6)2 (7), [Ag4(HL)2]- (NO3)2 (8), and [Au2(H2L)2]Cl2 (9) were obtained by using a metal salt as the precursor. All of the complexes are neutral or cationic dinuclear mesocates, except the silver nitrate derivative, which exhibits a tetranuclear cluster mesocate architecture. The crystal structures of the neutral and cationic copper(I), silver(I), and gold(I) complexes allow us to analyze the influence of synthetic methodology or the counterion role on both the micro- and macrostructures of the mesocates.

The tetranuclear linear complex [Dy4(1,1,4-H3Lr)2(OAc)6]·CH3OH (1·CH3OH) was satisfactorily prepared and characterized. Its X-ray structure shows that it contains two types of octacoordinated DyIII ions, with distorted triangular dodecahedral and square antiprism geometries. This complex is an SMM, with multiple relaxation pathways, and with an anisotropic energy barrier of 39.7 K. 1·CH3OH also operates as a luminescent thermometer in the 11–295 K range, with a maximum relative thermal sensitivity of 1.6% K−1 and a minimum temperature uncertainty of 1.1 K at 295 K. Thus, 1·CH3OH is the first Dy4 SMM with luminescent thermometry, and this system is a rare example of dysprosium SMM that accesses the thermometric characteristics involving the ligand ascribed to the triplet emission in combination with DyIII emission.

The mechanism of carbamate activation promoted by different metal ions has been explored in this work. The reaction of the carbamate ligand H2L with chloride metal salts (M = Ni, Cu, Zn, Cd) leads to the coordination of the metal ions to the ligand, causing hydrolysis of the systems. This self-immolation process results in mononuclear dihydrazone complexes, carbon dioxide and the release of alcohol species from the pendant groups of the carbamate ligand. The conditions under which this process occurs have been studied in detail.

The synthesis of nanosized metal–organic frameworks (NMOFs) is requisite for their application as injectable drug delivery systems (DDSs) and other biorelevant purposes. Herein, we have critically examined the role of different synthetic parameters leading to the production of UiO-66 crystals smaller than 100 nm. Of note, we demonstrate the co-modulator role conferred by halide ions, not only to produce NMOFs with precise morphology and size, but also to significantly improve the reaction yield. The resulting NMOFs are highly crystalline and exhibit sustained colloidal stability in different biologically relevant media. As a proof of concept, these NMOFs were loaded with Rhodamine 6G (R6G), which remained trapped in most common biologically relevant media. When incubated with living mammalian cells, the R6G-loaded NMOFs were efficiently internalized and did not impair cell viability even at relatively high doses.

Nanoparticles have now long demonstrated capabilities that make them attractive to use in biology and medicine. Some of them, such as lipid nanoparticles (SARS-CoV-2 vaccines) or metallic nanoparticles (contrast agents) are already approved for their use in the clinic. However, considering the constantly growing body of different formulations and the huge research around nanomaterials the number of candidates reaching clinical trials or being commercialized is minimal. The reasons behind being related to the “synthetic” and “foreign” character of their surface. Typically, nanomaterials aiming to develop a function or deliver a cargo locally, fail by showing strong off-target accumulation and generation of adverse responses, which is connected to their strong recognition by immune phagocytes primarily. Therefore, rendering in negligible numbers of nanoparticles developing their intended function. While a wide range of coatings has been applied to avoid certain interactions with the surrounding milieu, the issues remained. Taking advantage of the natural cell membranes, in an approach that resembles a cell transfer, the use of cell-derived surfaces has risen as an alternative to artificial coatings or encapsulation methods. Biomimetic technologies are based on the use of isolated natural components to provide autologous properties to the nanoparticle or cargo being encapsulated, thus, improving their therapeutic behavior. The main goal is to replicate the (bio)-physical properties and functionalities of the source cell and tissue, not only providing a stealthy character to the core but also taking advantage of homotypic properties, that could prove relevant for targeted strategies. Such biomimetic formulations have the potential to overcome the main issues of approaches to provide specific features and identities synthetically. In this review, we provide insight into the challenges of nano-biointerfaces for drug delivery; and the main applications of biomimetic materi

We present the first example of a silver double-tetranuclear cluster helicate [Ag4L2]2 obtained from a bisthiosemicarbazone ligand using electrochemical synthesis. This cluster helicate undergoes a rare desulfurization process in chloroform giving rise to a cationic silver dihelicate [Ag2(H2L)2]SO4. This is the first silver mediated desulfurization reaction

Son moit@s @s científic@s que teñen amosado un interese especial pola figura e a personalidade científica de Marie Anne Paulze Lavoisier publicando as máis variadas achegas ao longo dos últimos anos (Fernández, 2000; Bermejo e Pintos, 2011; Bermejo, 2013), pero todo o feito non semella dabondo para todo canto cremos significou a súa figura na historia da ciencia moderna. O noso interese polo estudo da figura de Marie Anne Paulze levounos a participar en moitas actividades para pór no seu lugar a esta científica salientable do século XVIII. En todas estas actividades tratamos de estudar e poñer en valor a labor científica de Marie Anne (González Noya et al., 2019; Pintos e Bermejo, 2010; Pintos et al. 2016). Nesta palestra presentaremos o noso estudo sobre as achegas científicas que temos atopado e que consideramos como pertencentes a Marie Anne. No noso afán por informar, divertir e educar traemos, novamente, a figura de Marie Anne Paulze Lavoisier para presentar as súas achegas científicas cunha intención clara: reivindicar o seu papel como científica.

Dinuclear [M(H3L1,2,4)]2 (M = Dy, Dy2; M = Ho, Ho2) complexes were isolated from an heptadentate aminophenol ligand. The crystal structures of Dy2∙2THF, and the pyridine adducts Dy2∙2Py and Ho2∙2Py, show that the complexes are dinuclear, with unsupported double phenoxide bridges, and that the N4O4 environment of the LnIII centres is distorted triangular dodecahedral. The magnetic analysis of Dy2 and Ho2 shows that Dy2 is a single molecular magnet (SMM), with a thermal‐activated zero‐field effective energy barrier (Ueff) of 367.7 K, the largest barrier shown by double phenoxide‐bridged dinuclear dysprosium complexes to date. Ho2is one of the scarce dinuclear complexes showing frequency‐dependence for the out‐of‐phase component of susceptibility, although it does not even show field‐induced SMM behaviour above 2 K. Ab initio calculations were done in order to shed light on the magnetic dynamics of the complexes, and these studies support the experimental magnetic results.

The mononuclear complexes [Dy(3Br,5Cl-H3L1,1,4)(D)]·solvate (D = H2O, solvate = 0.25MeOH, 1W·0.25MeOH; D = Py without solvate, 1Py), and [Dy(3NO2,5Br-H3L1,1,4)(H2O)] (2W) were isolated. The crystal structures of 1W·0.25MeOH, 1Py and 2W·2CH3C6H5 show that the DyIII ion is octacoordinated, in N4O4 or N5O3 environments, with distorted geometries, between square antiprism, biaugmented trigonal prism and triangular dodecahedral. A similar environment for the metal ion is shown in the chiral crystals of the diamagnetic yttrium analogue [Y(3Br,5Cl-H3L1,1,4)(MeOH)] (3M), which were spontaneously resolved. Magnetic analyses of the three dysprosium complexes, and their diluted analogous 1W@Y, 1Py@Y and 2W@Y, reveal that none of them seem to relax through an Orbach mechanism at Hdc = 0. However, the three complexes show Orbach relaxation under Hdc = 1000 Oe, and 1Py is the in-field SIM with the highest energy barrier among these complexes, with a Ueff value of 358 K. Analysis of ac magnetic data shows that the electron-withdrawing substituents on the phenol rings of the aminophenol ligands, as well as the auxiliary oxygen donors from water ligands, reduce the energy barriers of the complexes, which is attributed to a charge reduction in the coordinating atoms of the aminophenol donor. Ab initio calculations support the experimental results.

Since the potential anticancer activity of auranofin was discovered, gold compounds have attracted interest with a view to developing anticancer agents that follow cytotoxic mechanisms other than cisplatin. Two benzimidazole gold(I) derivatives containing triphenylphosphine (Au(pben)(PPh3)) (1) or triethylphosphine (Au(pben)(PEt3)) (2) were prepared and characterized by standard techniques. X-ray crystal structures for 1 and 2 were solved. The cytotoxicity of 1 and 2 was tested in human neuroblastoma SH-SY5Y cells. Cells were incubated with compounds for 24 h with concentrations ranging from 10 µM to 1 nM, and the half-maximal inhibitory concentration (IC50) was determined. 1 and 2 showed an IC50 of 2.7 and 1.6 µM, respectively. In order to better understand the type of cell death induced by compounds, neuroblastoma cells were stained with Annexin-FITC and propidium iodide. The fluorescence analysis revealed that compounds were inducing apoptosis; however, pre-treatment with the caspase inhibitor Z-VAD did not reduce cell death. Analysis of compound effects on caspase-3 activity and reactive oxygen species (ROS) production in SH-SY5Y cells revealed an antiproliferative ability mediated through oxidative stress and both caspase-dependent and caspase-independent mechanisms

The synthetic nucleoside acyclovir is considered an outstanding model of the natural nucleoside guanosine. With the purpose of deepening on the influence and nature of non-covalent interactions regarding molecular recognition patterns, three novel Cu(II) complexes, involving acyclovir (acv) and the ligand receptor N-(2-hydroxyethyl)ethylenediamine (hen), have been synthesized and thoroughly characterized. The three novel compounds introduce none, one or two acyclovir molecules, respectively. Molecular recognition has been evaluated using single crystal X-ray diffraction. Furthermore, theoretical calculations and other physical methods such as thermogravimetric analysis, infrared and UV-Vis spectroscopy, electron paramagnetic resonance and magnetic measurements have been used. Theoretical calculations are in line with experimental results, supporting the relevance of the [metal-N7(acv) + H-bond] molecular recognition pattern. It was also shown that (hen)O-H group is used as preferred H-donor when it is found within the basal coordination plane, since the higher polarity of the terminal (hen)O-H versus the N-H group favours its implication. Otherwise, when (hen)O-H occupies the distal coordination site, (hen)N-H groups can take over

Ischemic stroke, caused by the interruption of blood flow to the brain and subsequent neuronal death, represents one of the main causes of disability in developed countries. Therapeutic methods such as recanalization approaches, neuroprotective drugs, or recovery strategies have been widely developed to improve the patient’s outcome; however, important limitations such as a narrow therapeutic window, the ability to reach brain targets, or drug side effects constitute some of the main aspects that limit the clinical applicability of the current treatments. Nanotechnology has emerged as a promising tool to overcome many of these drug limitations and improve the efficacy of treatments for neurological diseases such as stroke. The use of nanoparticles as a contrast agent or as drug carriers to a specific target are some of the most common approaches developed in nanomedicine for stroke. Throughout this review, we have summarized our experience of using nanotechnology tools for the study of stroke and the search for novel therapies

Cyclometallated compounds have been extensively studied, in particular those with palladium and platinum. This is because of their possible applications in medicinal chemistry, as anticancer or antimicrobial agents; in some cases, with similar results as cisplatin, carboplatin or oxaliplatin. What is also remarkable is their use as homogeneous catalysts, for example, in cross coupling reactions such as Suzuki–Miyaura or Mizoroki–Heck. Herein, we report the synthesis of different thiosemicarbazone ligands, which will be reacted with a palladium or platinum salt, to give the corresponding cyclometallated compounds; in addition, their reactivity with bis(diphenylphosphino)methane (dppm) will be studied. Characterization has been carried out by elemental analysis, IR spectroscopy, 1H and 31P NMR spectroscopy. Additionally, 1c has been studied by X-ray diffraction

The mononuclear complex [Yb(H3L1,1,4)]·2MeOH (1·2MeOH), with a new heptadentate N4O3 ligand, was isolated and structurally characterised. The opto-magnetic properties of 1·2MeOH were investigated, showing that this complex is a bifunctional compound. Accordingly, 1·2MeOH reveals two coexisting functionalities: field-induced single molecule magnet behaviour, and Yb3+-centred NIR fluorescence dependent on temperature (25–300 K). The magnetic relaxation in this pentagonal bipyramidal complex does not seem to be of the Orbach type, and this is supported by the discrepancy between the anisotropic energy barrier found by fitting the magnetic data to an Orbach model and by spectroscopic studies. Ab initio calculations further validate the magnetic relaxation mechanisms and spectroscopic results.

The reactivity of the well-known pentadentate N3O2 Schiff base H2L (2,6-bis(2-hydroxyphenyliminomethyl)pyridine) towards a lanthanoid metal, in this case DyIII, has been investigated for the first time. This reactivity markedly depends on the pH of the medium and, accordingly, two different complexes, [Dy(HL)(NO3)2]·H2O (1·H2O) and [Dy(L)(NO3)(EtOH)(H2O)]·2H2O (2·2H2O), could be isolated from dysprosium(III) nitrate and H2L. In addition, reaction of H2L with dysprosium(III) chloride in methanol yields [Dy(HL′)2][Dy(L)(Cl2)] (3), where H2L′ ((6-(2-hydroxyphenyliminomethyl)-2-methoxyhydroxymethyl)pyridine) is an N2O2 hemiacetal donor derived from the partial hydrolysis of the H2L ligand, and subsequent addition of the methanol solvent to the carbonyl group. This latter reaction has been firstly observed for a lanthanoid metal. Single crystal X-ray diffraction studies of 1·1.15Py·0.3CH3C6H5, 2·2H2O and 3 show that the Schiff base is acting as a nearly flat pentadentate donor in all the cases, this behaviour being independent of the deprotonation degree of the phenolic oxygen atoms, both mono- or bisdeprotonated. Complexes 1·1.15Py·0.3CH3C6H5 and 2·2H2O show DyN3O6 cores, with distorted geometries closer to spherical tricapped trigonal prism or spherical capped square antiprism for 1·1.15Py·0.3CH3C6H5 and 2·2H2O, respectively. In the case of 3, the [Dy(HL′)2]+ cation shows a dysprosium ion in an N4O4 triangular dodecahedron environment, while the [Dy(L)(Cl2)]− anion displays a DyN3O2Cl2 core with distorted pentagonal bipyramidal geometry. Moreover, attempts to dilute 1·H2O with yttrium yielded single crystals of (Et3NH)[Dy0.09Y0.91(L)(NO3)2] (4), where the Schiff base shows a similar pentadentate coordination mode. Dynamic magnetic studies of 1·H2O, 2·2H2O and 3 show that 2·2H2O and 3 present field-induced slow relaxation of the magnetisation, with Ueff barriers of 46.1(9) and 31.0(7) K for 2·2H2O and 3, respectively, while 1·H2O does not exhibit frequency-dependent pea

Translating the potential of transition metal catalysis to biological and living environments promises to have a profound impact in chemical biology and biomedicine. A major challenge in the field is the creation of metal-based catalysts that remain active over time. Here, we demonstrate that embedding a reactive metallic core within a microporous metal-organic framework-based cloak preserves the catalytic site from passivation and deactivation, while allowing a suitable diffusion of the reactants. Specifically, we report the fabrication of nanoreactors composed of a palladium nanocube core and a nanometric imidazolate framework, which behave as robust, long-lasting nanoreactors capable of removing propargylic groups from phenol-derived pro-fluorophores in biological milieu and inside living cells. These heterogeneous catalysts can be reused within the same cells, promoting the chemical transformation of recurrent batches of reactants. We also report the assembly of tissue-like 3D spheroids containing the nanoreactors and demonstrate that they can perform the reactions in a repeated manner

El agua es un medio líquido fundamental para el desarrollo de la vida, pero a pesar de su importancia, el conocimiento de sus propiedades está muy lejos de ser absoluto. En el presente trabajo, estudiaremos el efecto de diferentes solutos en el ordenamiento espacial de las moléculas de agua, lo que nos permitirá obtener información sobre las propiedades únicas de este medio. Comenzaremos analizando las características de la disolución acuosa del bromuro de tetrabutilfosfonio (TtBPBr). Este sistema, en condiciones de muy alta presión, da lugar a la formación de clatratos, lo que puede indicar la preexistencia de una estructura supramolecular en disolución. Posteriormente, estudiaremos la hidratación de alcoholes de cadena corta (etanol, 1- propanol, 2-propanol). Este proceso de solvatación de moléculas orgánicas, puede estar íntimamente relacionado con procesos de reconocimiento biomolecular, plegamiento de proteínas, etc. Por lo que su comprensión puede darnos cierta información sobre estos complejos mecanismos de los sistemas biológicos. Finalmente, trataremos de analizar las propiedades del agua líquida superenfriada. Para poder llevar esto a cabo, es necesario evitar la formación de centros de cristalización, esto se consigue con la adición de nitrato de etilamonio (EAN) y metanosulfonato de trietilamonio (TEAMS) en relación molar 9:1. Estas sales, sin alterar prácticamente las propiedades del medio, permiten superen rar el agua hasta temperaturas inferiores a 140 K, ofreciendo la posibilidad de conocer posibles anomalías a estas temperaturas, A auga é un medio fundamental para o desenvolvemento da vida, pero a pesar da súa importancia, o coñecemento das súas propiedades está moi lonxe de ser absoluto. No presente traballo, estudiaremos o efecto de diferentes solutos no ordenamento espacial das moléculas de auga, o que nos permitirá obter información sobre as propiedades únicas de este medio. Comezaremos analizando as características da disolución acuosa do bromuro de tetrabutilfosfonio (TtBPBr). Este sistema, en condicións de moi alta presión, da lugar á formación de clatratos, o que pode indicar a preexistencia dunha estructura supramolecular en disolución. Posteriormente, estudiaremos a hidratación de alcois de cadea corta (etanol, 1-propanol, 2-propanol). Este proceso de solvatación de moléculas orgánicas, pode estar intimamente relacionado con procesos de recoñecemento biomolecular, pregamento de proteínas, etc. Polo tanto, a súa comprensión pode ofrecernos certa información sobre estos complexos mecanismos dos sistemas biolóxicos. Finalmente, trataremos de analizar as propiedades da auga líquida superenfriada. Para poder cumprir con este cometido, é necesario evitar a formación de centros de cristalización, isto conséguese coa adición de nitrato de etilamonio (EAN) e metanosulfonato de trietilamonio (TEAMS) en relación molar 9:1. Estas sales, sen alterar prácticamente as propiedades do medio, permiten superenfriar a auga ata temperaturas inferiores aos 140 K, ofrecendo a posibilidade de coñecer posibles anomalías a estas temperaturas, Water is a fundamental liquid medium for the development of life, but despite its importance, the knowledge about its properties is far to be absolute. In this project, we will study the e ect of di erent solutes on the spatial arrangement of water molecules, which will allow us to obtain information about the unique properties of this medium. We will start by analysing the aqueous solution of tetrabutyl phosphoniumbromide (TtBPBr). This system, under high-pressure conditions, leads to the formation of clathrate hydrates, an aspect which may indicate the existence of a supramolecular structure in solution. Then, we will study the hydration of short-chain alcohols (ethanol, 1-propanol, 2- propanol). This process of solvation of organic molecules may be involved in biomolecular recognition, protein folding, etc. Due to this fact, their understanding may give us certain information about these complex mechanisms of biological systems. Finally, we will try to analyse the properties of supercooled water. In order to achieve this, it is necessary to avoid the formation of crystallization centers. The solution which we have taken consists in the addition of ethylammonium nitrate (EAN) and triethylammonium methaneosulfonate (TEAMS) in molar ratio 9:1. These salts, without inducing important changes in the thermodynamics properties, o er the possibility to supercool water under 140 K, providing a way to study liquid water at low temperatures

The search for mononuclear lanthanoid-based single-ion magnets (SIMs) has increased the interest in some coordination environments with low coordination numbers, in combination with an axial symmetry, as they could maximize the anisotropy of complexes of oblate lanthanoid ions, such as dysprosium(III). In this sense, the pentagonal–bipyramid geometry can have ground-state doublets with perfect axiality, and therefore such complexes can be good candidates for SIMs. In our particular case, we have used a well-known open planar pentadentate chelating Schiff base ligand as 2,6-bis(1-salicyloylhydrazonoethyl)pyridine) (H4daps) for the synthesis of air-stable pentagonal–bipyramidal LnIII complexes (these being Ln: Dy and Er, oblate and prolate, respectively), in order to compare their structures. Thus, the reaction of H4daps with (CH3)4NOH·5H2O and the corresponding LnCl3·hexahydrate has yielded heptacoordinate [(CH3)4N][LnIII(H2daps)Cl2] complexes, where the tetramethylammonium cation is acting as the counterion of pentagonal–bipyramidal LnIII complexes, which are bearing two chloride atoms in apical positions. As both complexes could be crystallized as single crystals, we can compare their crystal structures, as well as with some other related complexes in the literature, which contain different counterions, trying to see their influence on other properties of the compounds, such as their magnetic behavior

The effect of the ligand and/or metal-related factors on the formation of tristhiosemicarbazone metallosupramolecular complexes has been studied in this work. The crystal structures of zinc(II) and lead(II) tristhiosemicarbazone mesocates and a hydrolyzed cadmium(II) helicate let us better rationalize some factors involved in the selective formation of helicates or mesocates.

A series of phosphino-thiosemicarbazone gold(I) dinuclear complexes obtained by two different synthetic pro- cedures have been prepared. All the compounds have been spectroscopically characterized including single crystal X ray diffraction analysis in some of cases. [Au2(HL1)Cl2] (1), [Au2(HL2)2]Cl2 (2) and [Au2(HL3)2]Cl2 (3) have been prepared by chemical synthesis using a gold(III) salt as precursor; while [Au2(L1)2] (4), [Au2(L2)2] ∙2CH3CN (5) and [Au2(L3)2] (6) have been isolated from an electrochemical synthesis (HLn=2-[2-(diphenyl- phosphanyl)-benzylidene]-N-R-thiosemicarbazone; HL1: R=methyl, HL2: R=methoxyphenyl, HL3: R=nitrophenyl). The in vitro cytotoxic activity of these gold(I) complexes was tested against some human tumor cell lines: HeLa 229 (cervical epithelial carcinoma), MCF-7 (ovarian adenocarcinoma), NCI-H460 (non- small-cell lung cancer) and MRC5 (normal human lung fibroblast), and the IC50 values compared with those of cisplatin. The neutral methyl-substituted complexes 1 and 4 and methoxyphenyl 5 displayed significant cyto- toxic activities in all investigated cancer cell lines, being 1 and 4 the most effective. The ability of complexes 1 and 4 to induce cell death by apoptosis in Hela 229 was also investigated by fluorescence microscopy using the apoptotic DNA fragmentation as marker. These results indicated that the inhibition of cell proliferation is mainly due to an apoptotic process. In order to obtain more information about the mechanism of action of these me- tallocompounds, the interactions of complexes 1 and 4 with the thioredoxin reductase (TrxR) enzyme were analyzed. Both complexes exhibited a strong inhibition of the thioredoxin reductase activity.

The asymmetric 3,5-disubstituted 1,2,4-triazole ligand H2V (5-amino-3-picolinamido-1,2,4-triazole) by reaction with an excess of Cu(II) perchlorate (Cu : H2V being 12 : 1) has produced a novel hexanuclear {Cu6(m3-O/H)(HV/V)3} fragment, with one triangular Cu3(m3-O/H) group connected to three peripheral single Cu(II) ions through a cis–cis–trans bridging mode of the ligand, which is the building block of the three structures described here: one hexanuclear, [Cu6(m3-O)(HV)3(ClO4)7(H2O)9]$8H2O (1), one dodecanuclear, [Cu12(m3-O)2(V)6(ClO4)5(H2O)18](ClO4)3$6H2O (2), and one tetradecanuclear 1D-polymer, {[Cu14(m3-OH)2(V)6(HV)(ClO4)11(H2O)20](ClO4)2$14H2O}n (3), the last two containing hexanuclear subunits linked by perchlorato bridges. The Cu–Cu av. intra-triangle distance is 3.352(2) A and the Cu(central) ˚ – Cu(bridged external) av. distance is 5.338(3) A. The magnetic properties of the hexanuclear ˚ “Cu3O–3Cu” cluster have been studied, resulting as best fit parameters: g ¼ 2.18(1), J(intra-triangle) ¼ 247.0(1) cm1 and j(central CuII – external CuII) ¼ 5.15(2) cm1 .

We have explored the suitability of an O,N,N–donor Schiff base (H2SB) for obtaining dinuclear complexes with heavy metal ions such as Cu2+, Zn2+, Ni2+, and Co2+ (borderline acids) as well as Pd2+ and Cd2+ (soft acids). Spectroscopic studies demonstrated that the complexation of H2SB and Cu2+, Zn2+, Ni2+, Co2+, Pd2+, and Cd2+ occurred at a 1:1 stoichiometry. We have found two square planar centers with Pd-N-Pd angles of 93.08(11)° and a Pd–Pd distance of 3.0102(4) Å in Pd2(SB)2·Me2CO. This Pd–Pd distance is 30% shorter than the sum of the van der Waals radii, which is in accordance with a strong palladophilic interaction. Fluorescence studies on H2SB-M2+ interaction showed that H2SB can detect Cu2+ ions in a sample matrix containing various metal ions (hard, soft, or borderline acids) without interference. Determination of binding constants showed that H2SB has a greater affinity for borderline acids than for soft acids

Since the discovery of single molecule magnetism in a Mn12 complex in 1993, the research on this field has received growing attention. This is mainly due to the great advantages that the molecular magnets would have in storage and data processing with respect to the classic magnets. Moreover, on basis on their quantum size effects, other applications beyond high-density information storage have been proposed, such as spintronics or qubits for quantum computing. This special issue in Molecular Magnets compiles 7 articles on the latest advances in this research topic

Lignin and other colored structures need to be bleached after the Kraft process in the pulp industry. Development of environmentally-safe bleaching catalysts or electrocatalysts constitutes an attractive strategy for selective removal of lignin. Seven manganese(III)-complexes with Schiff base ligands 1–7 were synthetized and characterized by different analytical and spectroscopic techniques. The tetragonally elongated octahedral geometry for the manganese coordination sphere and the global µ-aquo dimeric structure were revealed by X-ray diffraction (XRD) studies for 1, Mn2L12(H2O)2(N(CN)2)2 (N(CN)2 = dicyanamide). Complexes 1–4 behave as more efficient peroxidase mimics as compared to 5–7. Electrochemical oxidation of the lignin model veratrylalcohol (VA) to veratrylaldehyde (VAH) is efficiently catalyzed by a type of dimanganese(III) complexes in a chlorine-free medium. The electrocatalytic reaction proceeds through the oxidation of chloride into hypochlorite at alkaline pH along with the formation of hydrogen from water as a subproduct

Nesta comunicación queremos presentar as mulleres pioneiras de Lugo que a finais do século XIX e comezo do XX estudaron carreiras universitarias de Ciencias. Pretendemos dar unha visión do comezo da presenza da muller na universidade e máis concretamente nas carreiras consideradas de ciencias (Farmacia, Medicina, Física, Química, Matemáticas), mostrar o desenvolvemento da súa actividade profesional e que así sexa coñecido o seu labor e valorado na súa xusta medida. É máis importante e destacada do que poderiamos pensar, xa que como veremos temos un bo número de mulleres pioneiras que se prepararon e que desenvolveron a súa profesión dunha maneira seria e calada, que fixo que pasaran case desapercibidas salvo para as mulleres próximas, parentes ou non, e que as tomaron como exemplo para seguir a mesma traxectoria. Con esta visión feminista amosamos ás que hoxe desenvolven a práctica docente e ás novas xeracións o camiño xa feito, para tamén deixar patente o noso agradecemento ás loitadoras polo dereito a facer unha carreira universitaria, á par que as recoñecemos como exemplo e incidimos no que aínda nos queda por conseguir. Rescatar e poñer en valor estas pioneiras é contar esa metade da historia que está por contar, así como sentar as bases sobre as que se basearon e desenvolveron os estudos e profesións das mulleres actuais que nun número pequeno pero importante xa vai formando parte do mundo científico e tecnolóxico, mulleres que cursaron e cursan carreiras STEM ‹Science, Technology, Engineering and Mathematics›

Multifunctional nanoreactors are assembled using hollow graphitized carbon nanofibers (GNFs) combined with nanocatalysts (Pd or Pt) and magnetic nanoparticles. The latter are introduced in the form of carbon‐coated cobalt nanomagnets (Co@Cn) adsorbed on GNF, or formed directly on GNF from ferrocene yielding carbon‐coated iron nanomagnets (Fe@Cn). High‐resolution transmission electron microscopy demonstrates that Co@Cn and Fe@Cn are attached effectively to the GNFs, and the loading of nanomagnets required for separation of the nanoreactors from the solution with an external magnetic field is determined using UV–vis spectroscopy. Magnetically functionalized GNFs combined with palladium or platinum nanoparticles result in catalytically active magnetically separable nanoreactors. Applied to the reduction of nitrobenzene the multifunctional nanoreactors demonstrate high activity and excellent durability, while their magnetic recovery enables significant improvement in the reuse of the nanocatalyst over five reaction cycles (catalyst loss < 0.5 wt%) as compared to the catalyst recovery by filtration (catalyst loss <10 wt%)

The coordination chemistry of dysprosium and terbium toward phosphine and arsine oxides was further explored. Thus, the new nitrate [M(NO3)3(Ph3PO)3] (M = Tb, 1; Dy, 2), [Dy(NO3)3(EtOH)(Ph3XO)2] (X = P, 3; As, 4), chloride [DyCl2(Ph3AsO)4]Cl (5), triflate [Dy(OTf)2(MePh2PO)4]OTf (6; OTf = triflate) and hexafluoroacetylacetonate [M(hfa)3(Ph3PO)2] (hfa = hexafluoroacetylacetonate; M = Tb, 7; Dy, 8) complexes were isolated and fully characterized. The crystal structures of 1·CH3CN, 2·CH3CN, 4, 5·2.75EtOH·1.25H2O, 6, 7, and 8 show MO9 cores in 1, 2, and 4, with highly distorted geometry, between spherical capped square antiprism and muffin-like, hexacoordinated environments for the dysprosium ions in 5 and 6, with octahedral geometry, and octa-coordination for the lanthanoid metals in 7 and 8, with geometry closer to square antiprism. Comparison of the magnetic behavior of all the complexes allows analyzing which metal ion (Tb or Dy), phosphine or arsine oxide, or anionic ligand favor more the slow relaxation of the magnetization. Alternating current magnetic measurements show that only 2, 4, and 8 present slow relaxation of the magnetization in the presence of an external magnetic field, 8 being the complex with the highest Ueff (44.85 K) of those described herein

We propose that peptides are highly versatile platforms for the precise design of supramolecular metal architectures, and particularly, for the controlled assembly of helicates. In this context, we show that the bacteriophage T4 Fibritin foldon (T4Ff) can been engineered on its N-terminus with metal-chelating 2,2′-bipyridine units that stereoselectively assemble in the presence of Fe(II) into parallel, three-stranded peptide helicates with preferred helical orientation. Modeling studies support the proposed self-assembly and the stability of the final helicate. Furthermore, we show that these designed mini-metalloproteins selectively recognize three-way DNA junctions over double-stranded DNA

A set of Ru(II) metallopeptides containing the dppz ligand has been synthesized using SPPS methods. Fluorescence titration studies show that those metallopeptides featuring an octaarginine tail display a large binding preference for DNA G-quadruplex structures over those lacking it, and also that the interplay between the octoarginine functionalization and the ancillary ligand in the complex has an essential role in the recognition process. Furthermore, the oligoarginine metallopeptides are also efficiently internalized, causing cell death with signs of apoptosis

Here we report the synthesis and characterization of a mononuclear gadolinium complex (Gd) and two heteronuclear Zn-Gd complexes (ZnGd and Zn2Gd), which contain two similar three-armed ligands that display an external compartment suitable for lanthanoid ions, and two internal compartments adequate for zinc (II) ions [H3L′ = (2-(3-formyl-2-hydroxy-5-methyl phenyl)-1,3-bis[4 -(3-formyl-2-hydroxy-5-methylphenyl)-3-azabut-3-enyl]-1,3-imidazolidine; H3L = 2-(5-bromo-2-hydroxy-3-methoxyphenyl)-1,3-bis[4-(5-bromo-2-hydroxy-3-methoxyphenyl)-3-azabut-3-enyl]-1,3-imidazolidine]. The synthetic methods used were varied, but the use of a metalloligand, [Zn2(L)AcO], as starting material was the key factor to obtain the heterotrinuclear complex Zn2Gd. The structure of the precursor dinuclear zinc complex is mostly preserved in this complex, since it is based on a compact [Zn2Ln(L)(OH)(H2O)]3+ residue, with a µ3-OH bridge between the three metal centers, which are almost forming an isosceles triangle. The asymmetric spatial arrangement of other ancillary ligands leads to chirality, what contrasts with the totally symmetric mononuclear gadolinium complex Gd. These features were confirmed by the crystal structures of both complexes. Despite the presence of the bulky compartmental Schiff base ligand, the chiral heterotrinuclear complex forms an intricate network which is predominately expanded in two dimensions, through varied H-bonds that connect not only the ancillary ligands, but also the nitrate counterions and some solvated molecules. In addition, some preliminary magnetic resonance imaging (MRI) studies have been made to determine the relaxivities of the three gadolinium complexes, with apparently improved T1 and T2 relaxivities with increasing zinc nuclearity, since both transversal and longitudinal relaxivities appear to enhance in the sequence Gd < ZnGd < Zn2Gd.

Inspired by natural transcription factors (TFs), researchers have explored the potential of artificial peptides for the recognition of specific DNA sequences, developing increasingly sophisticated systems that not only display excellent DNA binding properties, but also are endowed with new properties not found in their natural counterparts. Here we review some of the developments in the field of artificial peptide‐based DNA binders, focusing on the supramolecular and molecular design aspects of such systems

Magnetic nanomaterials show significant promise as contrast agents for magnetic resonance imaging (MRI). We have developed a new highly efficient one-step procedure for the synthesis of magnetically-functionalised hollow carbon nanofibres, where (i) the carbon nanofibres act as both a template and a support for the nucleation and growth of magnetite nanoparticles and (ii) the structural (size, dispersity and morphology) and functional (magnetisation and coercivity) properties of the magnetic nanoparticles formed on nanofibres are strictly controlled by the mass ratio of the magnetite precursor to the nanofibres and the solvent employed during synthesis. We have shown that our magnetitenanofibre materials are effectively solubilised in water resulting in a stable suspension that has been employed as a “negative” MRI contrast agent with an excellent transverse relaxivity (r2) of (268 ± 13) mM/s, surpassing current commercial materials and state-of-the-art magnetic nanoscale platforms in performance for MRI contrast at high magnetic fields. The 2 preparation and evaluation of this unique hybrid nanomaterial represents a critical step towards the realisation of a highly efficient “smart” MRI theranostic agent – a material that allows for the combined diagnosis (with MRI), treatment (with magnetic targeting) and follow-up of a disease (with MRI) – currently in high demand for various clinical applications, including stratified nanomedicine.