[Incidence of intrahospitalary major cardiac events with the use of mechanic thromboaspiration versus only use of IIB/IIIA glucoprotein inhibitors on patients with acute ST elevation myocardial infarction]. / Incidencia de eventos cardiovasculares mayores intrahospitalarios en pacientes sometidos a tromboaspiración mecánica más IIb/IIIa contra solo inhibidores de la glucoproteína IIb/IIIa en infarto agudo al miocardio con elevación del segmento ST.

Objective: To identify the incidence of in-hospital major adverse cardiac events (MACE) with the use of mechanic thromboaspiration plus IIb/IIIa glycoprotein inhibitors versus only use of IIb/IIIa glycoprotein inhibitors on patients with acute ST elevation myocardial infarction. Method: Retrospective, observational, cohort analytic study, on patients with acute ST elevation myocardial infarction that had angiography thrombus TIMI 5 grade, treated between October 2021 and December 2022. Results: A total of 237 patients were included. In 113 patients thromboaspiration were used, 124 patients didn't used. 81.6% were men. In-hospital MACE occurred on 31.9% of patients with thromboaspiration use vs. 30.6% on patients with no use (RR: 1.05; IC95%: 0.61-1.93; p = 0.840). Incidence of malignant arrhythmias were of 8% with thromboaspiration use vs. 1.6% on patients with no use (RR: 5.27; IC95%: 1.11-24.97; p = 0.020). Conclusions: The use of thromboaspiration on concomitant treatment with IIb/IIIa glycoprotein inhibitors was similar with only IIb/IIIa glycoprotein inhibitors in reducing incidence of in-hospital MACE on patients with ST elevation acute myocardial infarction and high thrombus burden. The study has several limitations, so results should be taken with caution.

Objetivo: Identificar la incidencia de eventos cardiovasculares adversos mayores (ECAM) intrahospitalarios con el uso de tromboaspiración mecánica más inhibidores de la glucoproteína IIb/IIIa contra solo inhibidores de la glucoproteína IIb/IIIa en pacientes con infarto agudo al miocardio con elevación del segmento ST (IAMCEST). Método: Estudio retrospectivo, observacional, analítico, de cohorte, en pacientes con IAMCEST con trombo angiográfico de grado TIMI 5, tratados entre octubre de 2021 y diciembre de 2022. Resultados: Cumplieron los criterios de inclusión 237 pacientes. En 113 se usó tromboaspirador más inhibidores IIb/IIIa y en 124 solo inhibidores IIb/IIIa. El 81.6% fueron hombres. La incidencia de ECAM intrahospitalarios fue del 31.9% en los pacientes con tromboaspiración y del 30.6% en los pacientes con solo inhibidores IIb/IIIa (RR: 1.05; IC95%: 0.61-1.93; p = 0.840). La incidencia de arritmias graves fue del 8% en los pacientes con tromboaspiración y del 1.6% en los pacientes con solo inhibidores IIb/IIIa (RR: 5.27; IC95%: 1.11-24.97; p = 0.020). Conclusiones: La frecuencia de ECAM asociados al uso de tromboaspiración mecánica como coadyuvante a los inhibidores de la glucoproteína IIb/IIIa en pacientes con IAMCEST y trombo angiográfico de grado TIMI 5 no es diferente de la de aquellos pacientes en las que solo se utilizan inhibidores de la glucoproteína IIb/IIa. El estudio tiene varias limitaciones, por lo que los resultados deben tomarse con cautela.

Activating a high-spin iron(II) complex to thermal spin-crossover with an inert non-isomorphous molecular dopant.

[Fe(bpp)2][ClO4]2 (bpp = 2,6-bis{pyrazol-1-yl}pyridine; monoclinic, C2/c) is high-spin between 5-300 K, and crystallises with a highly distorted molecular geometry that lies along the octahedral-trigonal prismatic distortion pathway. In contrast, [Ni(bpp)2][ClO4]2 (monoclinic, P21) adopts a more regular, near-octahedral coordination geometry. Gas phase DFT minimisations (ω-B97X-D/6-311G**) of [M(bpp)2]2+ complexes show the energy penalty associated with that coordination geometry distortion runs as M2+ = Fe2+ (HS) ≈ Mn2+ (HS) < Zn2+ ≈ Co2+ (HS) ≲ Cu2+ ≪ Ni2+ ≪ Ru2+ (LS; HS = high-spin, LS = low-spin). Slowly crystallised solid solutions [FexNi1-x(bpp)2][ClO4]2 with x = 0.53 (1a) and 0.74 (2a) adopt the P21 lattice, while x = 0.87 (3a) and 0.94 (4a) are mixed-phase materials with the high-spin C2/c phase as the major component. These materials exhibit thermal spin-transitions at T½ = 250 ± 1 K which occurs gradually in 1a, and abruptly and with narrow thermal hysteresis in 2a-4a. The transition proceeds to 100% completeness in 1a and 2a; that is, the 26% Ni doping in 2a is enough to convert high-spin [Fe(bpp)2][ClO4]2 into a cooperative, fully SCO-active material. These results were confirmed crystallographically for 1a and 2a, which revealed similarities and differences between these materials and the previously published [FexNi1-x(bpp)2][BF4]2 series. Rapidly precipitated powders with the same compositions (1b-4b) mostly resemble 1a-4a, except that 2b is a mixed-phase material; 2b-4b also contain a fraction of amorphous solid in addition to the two crystal phases. The largest iron fraction that can be accommodated by the P21 phase in this system is 0.7 ± 0.1.

CHRNA6 RNA In Situ Hybridization Is a Useful Tool for the Diagnosis of Extraskeletal Myxoid Chondrosarcoma.

Extraskeletal myxoid chondrosarcoma (EMC) is an uncommon mesenchymal neoplasm characteristically composed of uniform-appearing round to spindle-shaped cells with eosinophilic cytoplasm and abundant myxoid extracellular matrix. Although the majority of cases harbor a pathognomonic t(9;22) translocation that fuses EWSR1 with the orphan nuclear receptor NR4A3, there are less common variants that partner NR4A3 with TAF15, TCF12, or TFG. By immunohistochemistry, EMC has features of both cartilaginous and neuroendocrine differentiation, as evidenced by inconsistent expression of S100 protein and synaptophysin or INSM1, respectively, in a subset of cases. Given the limitations of available immunohistochemical stains for the diagnosis of EMC, we analyzed genome-wide gene expression microarray data to identify candidate biomarkers based on differential expression in EMC in comparison with other mesenchymal neoplasms. This analysis pointed to CHRNA6 as the gene with the highest relative expression in EMC (96-fold; P = 8.2 × 10-26) and the only gene with >50-fold increased expression in EMC compared with other tumors. Using RNA chromogenic in situ hybridization, we observed strong and diffuse expression of CHRNA6 in 25 cases of EMC, including both EWSR1-rearranged and TAF15-rearranged variants. All examined cases of histologic mimics were negative for CHRNA6 overexpression; however, limited CHRNA6 expression, not reaching a threshold of >5 puncta or 1 aggregate of chromogen in >25% of cells, was observed in 69 of 685 mimics (10.1%), spanning an array of mesenchymal tumors. Taken together, these findings suggest that, with careful interpretation and the use of appropriate thresholds, CHRNA6 RNA chromogenic in situ hybridization is a potentially useful ancillary histologic tool for the diagnosis of EMC.

Di-Iron(II) [2+2] Helicates of Bis-(Dipyrazolylpyridine) Ligands: The Influence of the Ligand Linker Group on Spin State Properties.

Four bis[2-{pyrazol-1-yl}-6-{pyrazol-3-yl}pyridine] ligands have been synthesized, with butane-1,4-diyl (L1 ), pyrid-2,6-diyl (L2 ), benzene-1,2-dimethylenyl (L3 ) and propane-1,3-diyl (L4 ) linkers between the tridentate metal-binding domains. L1 and L2 form [Fe2 (µ-L)2 ]X4 (X- =BF4 - or ClO4 - ) helicate complexes when treated with the appropriate iron(II) precursor. Solvate crystals of [Fe2 (µ-L1 )2 ][BF4 ]4 exhibit three different helicate conformations, which differ in the torsions of their butanediyl linker groups. The solvates exhibit gradual thermal spin-crossover, with examples of stepwise switching and partial spin-crossover to a low-temperature mixed-spin form. Salts of [Fe2 (µ-L2 )2 ]4+ are high-spin, which reflects their highly twisted iron coordination geometry. The composition and dynamics of assembly structures formed by iron(II) with L1 -L3 vary with the ligand linker group, by mass spectrometry and 1 H NMR spectroscopy. Gas-phase DFT calculations imply the butanediyl linker conformation in [Fe2 (µ-L1 )2 ]4+ influences its spin state properties, but show anomalies attributed to intramolecular electrostatic repulsion between the iron atoms.

Micro-scale aerosol jet printing of superparamagnetic Fe3O4 nanoparticle patterns.

The opportunity to create different patterns of magnetic nanoparticles on surfaces is highly desirable across many technological and biomedical applications. In this paper, this ability is demonstrated for the first time using a computer-controlled aerosol jet printing (AJP) technology. AJP is an emerging digitally driven, non-contact and mask-less printing process which has distinguishing advantages over other patterning technologies as it offers high-resolution and versatile direct-write deposition of a wide range of materials onto a variety of substrates. This research demonstrates the ability of AJP to reliably print large-area, fine-feature patterns of superparamagnetic iron oxide nanoparticles (SPIONs) onto both rigid material (glass) and soft and flexible materials (polydimethylsiloxane (PDMS) films and poly-L-lactic acid (PLLA) nanofilms). Investigation identified and controlled influential process variables which permitted feature sizes in the region of 20 µm to be realised. This method could be employed for a wide range of applications that require a flexible and responsive process that permits high yield and rapid patterning of magnetic material over large areas. As a first proof of concept, we present patterned magnetic nanofilms with enhanced manipulability under external magnetic field gradient control and which are capable of performing complex movements such as rotation and bending, with applicability to soft robotics and biomedical engineering applications.

Iron(II) Complexes of 4-(Alkyldisulfanyl)-2,6-di(pyrazolyl)pyridine Derivatives. Correlation of Spin-Crossover Cooperativity with Molecular Structure Following Single-Crystal-to-Single-Crystal Desolvation.

The complex salts [Fe(L 1)2]X2 (1X 2 ; L 1 = 4-(isopropyldisulfanyl)-2,6-bis(pyrazolyl)pyridine; X- = BF4 -, ClO4 -) form solvated crystals from common organic solvents. Crystals of 1X 2 ·Me2CO show abrupt spin transitions near 160 K, with up to 22 K thermal hysteresis. 1X 2 ·Me2CO cocrystallizes with other, less cooperative acetone solvates, which all transform into the same solvent-free materials 1X 2 ·sf upon exposure to air, or mild heating. Conversion of 1X 2 ·Me2CO to 1X 2 ·sf proceeds in a single-crystal to single-crystal fashion. 1X 2 ·sf are not isomorphous with the acetone solvates, and exhibit abrupt spin transitions at low temperature with hysteresis loops of 30-38 K (X- = BF4 -) and 10-20 K (X- = ClO4 -), depending on the measurement method. Interestingly, the desolvation has an opposite effect on the SCO temperature and hysteresis in the two salts. The hysteretic spin transitions in 1X 2 ·Me2CO and 1X 2 ·sf do not involve a crystallographic phase change but are accompanied by a significant rearrangement of the metal coordination sphere. Other solvates 1X 2 ·MeNO2, 1X 2 ·MeCN, and 1X 2 ·H2O are mostly isomorphous with each other and show more gradual spin-crossover equilibria near room temperature. All three of these lattice types have similar unit cell dimensions and contain cations associated into chains through pairwise, intermolecular S···π interactions. Polycrystalline [Fe(L 2)2][BF4]2·MeNO2 (2[BF 4 ] 2 ·MeNO2; L 2 = 4-(methyldisulfanyl)-2,6-bis(pyrazolyl)pyridine) shows an abrupt spin transition just above room temperature, with an unsymmetrical and structured hysteresis loop, whose main features are reversible upon repeated thermal scanning.

Correction: Heteroleptic iron(II) complexes of chiral 2,6-bis(oxazolin-2-yl)-pyridine (PyBox) and 2,6-bis(thiazolin-2-yl)pyridine ligands - the interplay of two different ligands on the metal ion spin state.

Correction for 'Heteroleptic iron(II) complexes of chiral 2,6-bis(oxazolin-2-yl)-pyridine (PyBox) and 2,6-bis(thiazolin-2-yl)pyridine ligands - the interplay of two different ligands on the metal ion spin state' by Namrah Shahid et al., Dalton Trans., 2022, 51, 4262-4274, DOI: 10.1039/d2dt00393g.

Heteroleptic iron(II) complexes of chiral 2,6-bis(oxazolin-2-yl)-pyridine (PyBox) and 2,6-bis(thiazolin-2-yl)pyridine ligands - the interplay of two different ligands on the metal ion spin sate.

Complexation of Fe[ClO4]2·6H2O by 1 equiv. 2,6-bis((4S)-4-phenyl-4,5-dihydrooxazol-2-yl)pyridine ((S)-L1Ph) and 2,6-bis((4R)-4-phenyl-4,5-dihydrothiazol-2-yl)pyridine ((R)-L2Ph) cleanly affords [Fe((S)-L1Ph)((R)-L2Ph)][ClO4]2; [Fe((R)-L1iPr)((S)-L2iPr)][ClO4]2 (L1iPr = 2,6-bis(4-isopropyl-4,5-dihydrooxazol-2-yl)pyridine; L2iPr = 2,6-bis(4-isopropyl-4,5-dihydrothiazol-2-yl)pyridine) was prepared by a similar route. The compounds exhibit thermal spin-crossover in solution, at temperatures midway between the corresponding [Fe((R)-L1R)((S)-L1R)][ClO4]2 and [Fe((R)-L2R)((S)-L2R)][ClO4]2 (R = Ph or iPr) species. The spin states of [Fe(LR)(bimpy)][ClO4]2 and [Fe(LR)(bpp)][ClO4]2 (LR = L1R or L2R; bimpy = 2,6-bis(1H-benzimidazol-2-yl)pyridine; bpp = 2,6-di(pyrazol-1-yl)pyridine) are also reported, with most examples exhibiting gradual spin-crossover in solution and the solid state. Although some products undergo partial ligand exchange in solution by 1H NMR, their solution T½ values appear unaffected by this and correlate well with their spin state energies from gas phase DFT calculations. The high-spin state of [Fe(L2R)(bpp)]2+ is more stabilised than expected, compared to the other [Fe(LR)L]2+ complexes studied (L = bimpy, bpp or terpy). That is explained by an interplay between the relative σ-basicities and π-acidities of the two ligands in each molecule. The steric influence of their phenyl or isopropyl 'R' substituents stabilises the heteroleptic complexes by up to 5 kcal mol-1, compared to analogues lacking these groups.

Structures and Spin States of Iron(II) Complexes of Isomeric 2,6-Di(1,2,3-triazolyl)pyridine Ligands.

Iron(II) complex salts of 2,6-di(1,2,3-triazol-1-yl)pyridine (L1) are unexpectedly unstable in undried solvent. This is explained by the isolation of [Fe(L1)4(H2O)2][ClO4]2 and [Fe(NCS)2(L1)2(H2O)2]·L1, containing L1 bound as a monodentate ligand rather than in the expected tridentate fashion. These complexes associate into 44 grid structures through O-H···N hydrogen bonding; a solvate of a related 44 coordination framework, catena-[Cu(µ-L1)2(H2O)2][BF4]2, is also presented. The isomeric ligands 2,6-di(1,2,3-triazol-2-yl)pyridine (L2) and 2,6-di(1H-1,2,3-triazol-4-yl)pyridine (L3) bind to iron(II) in a more typical tridentate fashion. Solvates of [Fe(L3)2][ClO4]2 are low-spin and diamagnetic in the solid state and in solution, while [Fe(L2)2][ClO4]2 and [Co(L3)2][BF4]2 are fully high-spin. Treatment of L3 with methyl iodide affords 2,6-di(2-methyl-1,2,3-triazol-4-yl)pyridine (L4) and 2-(1-methyl-1,2,3-triazol-4-yl)-6-(2-methyl-1,2,3-triazol-4-yl)pyridine (L5). While salts of [Fe(L5)2]2+ are low-spin in the solid state, [Fe(L4)2][ClO4]2·H2O is high-spin, and [Fe(L4)2][ClO4]2·3MeNO2 exhibits a hysteretic spin transition to 50% completeness at T1/2 = 128 K (ΔT1/2 = 6 K). This transition proceeds via a symmetry-breaking phase transition to an unusual low-temperature phase containing three unique cation sites with high-spin, low-spin, and 1:1 mixed-spin populations. The unusual distribution of the spin states in the low-temperature phase reflects "spin-state frustration" of the mixed-spin cation site by an equal number of high-spin and low-spin nearest neighbors. Gas-phase density functional theory calculations reproduce the spin-state preferences of these and some related complexes. These highlight the interplay between the σ-basicity and π-acidity of the heterocyclic donors in this ligand type, which have opposing influences on the molecular ligand field. The Brønsted basicities of L1-L3 are very sensitive to the linkage isomerism of their triazolyl donors, which explains why their iron complex spin states show more variation than the better-known iron(II)/2,6-dipyrazolylpyridine system.

Spin-States of Diastereomeric Iron(II) Complexes of 2,6-Bis(thiazolin-2-yl)pyridine (ThioPyBox) Ligands and a Comparison with the Corresponding PyBox Derivatives.

This report investigates homoleptic iron(II) complexes of thiazolinyl analogues of chiral PyBox tridentate ligands: 2,6-bis(4-phenyl-4,5-dihydrothiazol-2-yl)pyridine (L1Ph), 2,6-bis(4-isopropyl-4,5-dihydrothiazol-2-yl)pyridine (L1iPr), and 2,6-bis(4-tert-butyl-4,5-dihydrothiazol-2-yl)pyridine (L1t-Bu). Crystallographic data imply the larger and more flexible thiazolinyl rings reduce steric clashes between the R substituents in homochiral [Fe((R)-L1R)2]2+ or [Fe((S)-L1R)2]2+ (R = Ph, iPr, or t-Bu), compared to their PyBox (L2R) analogues. Conversely, the larger heterocyclic S atoms are in close contact with the R substituents in heterochiral [Fe((R)-L1Ph)((S)-L1Ph)]2+, giving it a more sterically hindered ligand environment than that in [Fe((R)-L2Ph)((S)-L2Ph)]2+ (L2Ph = 2,6-bis(4-phenyl-4,5-dihydrooxazol-2-yl)pyridine). Preformed [Fe((R)-L1Ph)((S)-L1Ph)]2+ and [Fe((R)-L1iPr)((S)-L1iPr)]2+ do not racemize by ligand redistribution in CD3CN solution, but homochiral [Fe(L1iPr)2]2+ and [Fe(L1t-Bu)2]2+ both undergo partial ligand displacement in that solvent. Homochiral [Fe(L1Ph)2]2+ and [Fe(L1iPr)2]2+ exhibit spin-crossover equilibria in CD3CN, centered at 344 ± 6 K and 277 ± 1 K respectively, while their heterochiral congeners are essentially low-spin within the liquid range of the solvent. These data imply that the diastereomers of [Fe(L1Ph)2]2+ and [Fe(L1iPr)2]2+ show a greater difference in their spin-state behaviors than was previous found for [Fe(L2Ph)2]2+. Gas-phase DFT calculations (B86PW91/def2-SVP) of the [Fe(L1R)2]2+ and [Fe(L2R)2]2+ complexes reproduce most of the observed trends, but they overstabilize the high-spin state of SCO-active [Fe(L1iPr)2]2+ by ca. 1.5 kcal mol-1. This might reflect the influence of intramolecular dispersion interactions on the spin states of these compounds. Attempts to model this with the dispersion-corrected functionals B97-D2 or PBE-D3 were less successful than our original protocol, confirming that the spin states of sterically hindered molecules are a challenging computational problem.

The number and shape of lattice solvent molecules controls spin-crossover in an isomorphous series of crystalline solvate salts.

Crystals of [FeL2][BF4]2·nMeCN (L = N-(2,6-di{pyrazol-1-yl}pyrid-4-yl)acetamide; n = 1 or 2) and [FeL2][ClO4]2·MeCN are isomorphous. When n = 1 the compounds exhibit an abrupt, hysteretic spin-transition below 200 K, but when n = 2 the material remains high-spin on cooling. [FeL2]X2·EtCN (X- = BF4- or ClO4-) are isomorphous with the MeCN solvates and undergo their spin-transition at almost the same temperature. However this now occurs in two-steps via a re-entrant mixed-spin intermediate phase, which correlates with crystallographic ordering of the bent propionitrile molecule.

The flexibility of long chain substituents influences spin-crossover in isomorphous lipid bilayer crystals.

[Fe(bpp)2][BF4]2 (bpp = 2,6-di{pyrazol-1-yl}pyridine) derivatives with a bent geometry of hexadec-1-ynyl or hexadecyl pyrazole substituents are isomorphous, and high-spin at room temperature. However, only the latter compound undergoes an abrupt, stepwise spin-transition on cooling. This may reflect the different conformational flexibilities of their long chain substituents.

Enhanced Spin-Orbit Coupling in Heavy Metals via Molecular Coupling.

5d metals are used in electronics because of their high spin-orbit coupling (SOC) leading to efficient spin-electric conversion. When C60 is grown on a metal, the electronic structure is altered due to hybridization and charge transfer. In this work, we measure the spin Hall magnetoresistance for Pt/C60 and Ta/C60, finding that they are up to a factor of 6 higher than those for pristine metals, indicating a 20-60% increase in the spin Hall angle. At low fields of 1-30 mT, the presence of C60 increased the anisotropic magnetoresistance by up to 700%. Our measurements are supported by noncollinear density functional theory calculations, which predict a significant SOC enhancement by C60 that penetrates through the Pt layer, concomitant with trends in the magnetic moment of transport electrons acquired via SOC and symmetry breaking. The charge transfer and hybridization between the metal and C60 can be controlled by gating, so our results indicate the possibility of dynamically modifying the SOC of thin metals using molecular layers. This could be exploited in spin-transfer torque memories and pure spin current circuits.

Structural Transformations and Spin-Crossover in [FeL2 ]2+ Salts (L=4-{tert-Butylsulfanyl}-2,6-di{pyrazol-1-yl}pyridine): The Influence of Bulky Ligand Substituents.

4-(tert-Butylsulfanyl)-2,6-di(pyrazol-1-yl)pyridine (L) was obtained in low yield from a one-pot reaction of 2,4,6-trifluoropyridine with 2-methylpropane-2-thiolate and sodium pyrazolate in a 1:1:2 ratio. The materials [FeL2 ][BF4 ]2 ⋅solv (1[BF4 ]2 ⋅solv) and [FeL2 ][ClO4 ]2 ⋅solv (1[ClO4 ]2 ⋅solv; solv=MeNO2 , MeCN or Me2 CO) exhibit a variety of structures and spin-state behaviors including thermal spin-crossover (SCO). Solvent loss on heating 1[BF4 ]2 ⋅x MeNO2 (x≈2.3) occurs in two steps. The intermediate phase exhibits hysteretic SCO around 250 K, involving a "reverse-SCO" step in its warming cycle at a scan rate of 5 K min-1 . The reverse-SCO is not observed in a slower 1 K min-1 measurement, however, confirming its kinetic nature. The final product [FeL2 ][BF4 ]2 ⋅0.75 MeNO2 was crystallographically characterized, and shows abrupt but incomplete SCO at 172 K which correlates with disorder of an L ligand. The asymmetric unit of 1[BF4 ]2 ⋅y Me2 CO (y≈1.6) contains five unique complex molecules, four of which undergo gradual SCO in at least two discrete steps. Low-spin 1[ClO4 ]2 ⋅0.5 Me2 CO is not isostructural with its BF4 - congener, and undergoes single-crystal-to-single-crystal solvent loss with a tripling of the crystallographic unit cell volume, while retaining the P 1 ‾ space group. Three other solvate salts undergo gradual thermal SCO. Two of these are isomorphous at room temperature, but transform to different low-temperature phases when the materials are fully low-spin.

Engineering macrocyclic high performance pentagonal bipyramidal Dy(iii) single-ion magnets.

We generate a new air-stable pseudo-D5h Dy(iii) Single-Molecule Magnet (Ueff = 1108 K, TB = 14 K) by combining a weak equatorial ligand field from a macrocyclic LN5 ligand with a strong axial ligand field. Based on our synthetic blueprint, we use ab initio calculations to show the vast scope for macrocyclic engineering of magnetic anisotropy.

Modulating the Magnetic Properties of Copper(II)/Nitroxyl Heterospin Complexes by Suppression of the Jahn-Teller Distortion.

A series of six-coordinate [Cu(L)L1][BF4]2 (L1 = 2,6-bis{1-oxyl-4,4,5,5-tetramethyl-4,5-dihydro-1H-imidazol-2-yl}pyridine) complexes are reported. Ferromagnetic coupling between the Cu and L1 ligand spins is enhanced by an L coligand with distal methyl substituents, which is attributed to a sterically induced suppression of its Jahn-Teller distortion.

There is nothing wrong with being soft: using sulfur ligands to increase axiality in a Dy(iii) single-ion magnet.

A new air-stable sulfur-ligated Dy(iii) single-ion magnet has been successfully isolated with Ueff = 638 K and hysteresis loops open up to 7 K. In silico studies show that the S co-ligands significantly boost the axiality and that Te- and Se-donors have the potential to further enhance the magnetic properties.

Supramolecular Iron Metallocubanes Exhibiting Site-Selective Thermal and Light-Induced Spin-Crossover.

Treatment of Fe[BF4]2·6H2O with 4,6-di(pyrazol-1-yl)-1H-pyrimid-2-one (HL1) or 4,6-di(4-methylpyrazol-1-yl)-1H-pyrimid-2-one (HL2) affords solvated crystals of [{FeIII(OH2)6}⊂FeII8(µ-L)12][BF4]7 (1, HL = HL1; 2, HL = HL2). The centrosymmetric complexes contain a cubic arrangement of iron(II) centers, with bis-bidentate [L]- ligands bridging the edges of the cube. The encapsulated [Fe(OH2)6]3+ moiety templates the assembly through 12 O-H···O hydrogen bonds to the [L]- hydroxylate groups. All four unique iron(II) ions in the cages are crystallographically high-spin at 250 K, but they undergo a gradual high → low spin-crossover on cooling, which is predominantly centered on one iron(II) site and its symmetry-related congener. This was confirmed by magnetic susceptibility data, light-induced excited spin state trapping (LIESST) effect measurements, and, for 1, Mössbauer spectroscopy and diffuse reflectance data. The clusters are stable in MeCN solution, and 1 remains high-spin above 240 K in that solvent. The cubane assembly was not obtained from reactions using other iron(II) salts or 4,6-di(pyrazol-1-yl)pyrimidine ligands, highlighting the importance of hydrogen bonding in templating the cubane assembly.

Boosting axiality in stable high-coordinate Dy(iii) single-molecule magnets.

A new nine-coordinate, air-stable Dy(iii) single-ion magnet has been successfully isolated. Our in silico studies demonstrate that through carefully modulating the ligand electronics, the axiality can be boosted to generate Ucal barriers of over 600 K.

Preparation of functionalized magnetic nanoparticles conjugated with feroxamine and their evaluation for pathogen detection.

This work reports the preparation of a conjugate between amino-functionalized silica magnetite and the siderophore feroxamine. The morphology and properties of the conjugate and intermediate magnetic nanoparticles (MNPs) were examined by powder X-ray diffraction (XRD), Fourier Transform Infrared spectroscopy (FT-IR), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), magnetization studies, zeta potential measurements, Transmission Electron Microscopy (TEM) and Energy Dispersive X-ray (EDX) mapping. Furthermore, this study investigated the interaction between the functionalized magnetic NPs and Yersinia enterocolitica wild type (WC-A) using Scanning Electron Microscopy (SEM) and TEM images. In addition, the interaction between MNPs and a Y. enterocolitica mutant strain lacking feroxamine receptor FoxA, was also used to study the binding specificity. The results showed that the capture and isolation of Y. enterocolitica by the MNPs took place in all cases. Moreover, the specific interaction between the MNP conjugate and bacteria did not increase after blocking the free amine groups with t-butoxycarbonyl (Boc) and carboxylic acid (COOH) functional groups. Electrostatic surface interactions instead of molecular recognition between MNP conjugate and feroxamine receptor seem to rule the attachment of bacteria to the conjugate.