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The stimulator of interferon genes (STING) pathway is a potent therapeutic target for innate immunity. Despite the efforts to develop pocket‐dependent small‐molecule STING agonists that mimic the endogenous STING ligand, cyclic guanosine monophosphate–adenosine monophosphate (cGAMP), most of these agonists showed disappointing results in clinical trials owing to the limitations of the STING pocket. In this study, we developed novel pocket‐independent STING‐activating agonists (piSTINGs), which act through multivalency‐driven oligomerization to activate STING. Additionally, a piSTING‐adjuvanted vaccine elicited a significant antibody response and inhibited tumour growth in therapeutic models. Moreover, a piSTING‐based vaccine combination with aPD‐1 showed remarkable potential to enhance the effectiveness of immune checkpoint blockade (ICB) immunotherapy. In particular, piSTING can strengthen the impact of STING pathway in immunotherapy and accelerate the clinical translation of STING agonists. [ABSTRACT FROM AUTHOR]

Aim: To explore the relationship between the serum sodium level on admission and all‐cause mortality in HF patients. Design: A single‐center retrospective cohort study. Methods: Patients hospitalized with HF at the Heart Failure Center, Fuwai Hospital, from November 2008 to November 2018 were enrolled. Results: A total of 3649 patients were included, and the mean sodium level was 137.19 ± 4.36 mmol/L, with a range from 115.6 to 160.9 mmol/L. During a median follow‐up of 1101 days, mortality occurred in 1413 (38.7%) hospital survivors. After adjustment for age, sex, and other potential confounders, patients with sodium levels <135 mmol/L (hazard ratio [HR]: 1.67; 95% confidence interval [CI]: 1.29–2.16) and 135–137 mmol/L (HR: 1.34; 95% CI: 1.01–1.78) had an increased risk of all‐cause mortality compared to those with sodium levels of 139–141 mmol/L. [ABSTRACT FROM AUTHOR]

Novel pocket‐independent STING‐activating agonists (piSTINGs), which act through multivalency‐driven oligomerization to activate downstream signalling pathways, were developed by Yan‐Mei Li et al. in their Research Article (e202407037). piSTINGs could serve as novel STING agonists for vaccines and combination therapies. STING oligomerization is a useful strategy for the development of a new generation of STING agonists...By Shao‐Hua Zhuo; Tian‐Yang Wang; Lang Zhao; Jing‐Yun Su; Jin‐Jian Hu; Yu‐Fen Zhao and Yan‐Mei LiReported by Author; Author; Author; Author; Author; Author; Author [Extracted from the article]

Novel pocket‐independent STING‐activating agonists (piSTINGs), which act through multivalency‐driven oligomerization to activate downstream signalling pathways, were developed by Yan‐Mei Li et al. in their Research Article (e202407037). piSTINGs could serve as novel STING agonists for vaccines and combination therapies. STING oligomerization is a useful strategy for the development of a new generation of STING agonists...By Shao‐Hua Zhuo; Tian‐Yang Wang; Lang Zhao; Jing‐Yun Su; Jin‐Jian Hu; Yu‐Fen Zhao and Yan‐Mei LiReported by Author; Author; Author; Author; Author; Author; Author [Extracted from the article]

Aims: Evidence of the prognostic value of high‐sensitivity troponin in patients with non‐ischaemic heart failure (NIHF) is scarce. This study aimed to assess the predictive value of high‐sensitivity cardiac troponin I (hs‐cTnI) in NIHF patients. Methods: Hs‐cTnI was measured at baseline in 650 NIHF patients admitted to the Heart Failure Center. The prognostic value of hs‐cTnI was assessed based on a well‐established model (including age, sex, New York Heart Association class, left ventricular ejection fraction, haemoglobin, sodium, estimated glomerular filtration rate, diabetes mellitus, treatment with angiotensin‐converting enzyme inhibitors or angiotensin II receptor blockers, treatment with β‐blockers, and NT‐proBNP). Results: During a median follow‐up of 1036 days, 163 patients died of various causes. In total, 46.92% of patients had high hs‐cTnI (hs‐cTnI >0.011 ng/ml). Over a 3‐year follow‐up, patients with high hs‐cTnI (>0.011 ng/ml) had a 1.54 [95% confidence interval (95% CI) 1.11–2.15] fold higher all‐cause mortality risk than those without. Increasing concertation of hs‐cTnI was also associated with a 23.0% (95% CI 13–33%, per log2 increase) increment risk of all‐cause mortality. The inclusion of hs‐cTnI significantly improved the risk prediction and stratification of all‐cause mortality (integrated discrimination improvement 1.58%, 95% CI 0.38–2.79%, absolute net reclassification improvement 23.41% 95% CI 4.52–44.49%, additive net reclassification improvement 27.8%, 95% CI 9.29–46.3%) of the well‐established model. Conclusions: Hs‐cTnI provides significant prognostic value and could further remarkably improve risk stratification and prediction capabilities in NIHF patients. [ABSTRACT FROM AUTHOR]

Aims: The prognostic significance of D‐dimer in hospitalized heart failure (HF) patients is incompletely characterized. We aimed to assess the association of D‐dimer levels on admission with adverse events at follow‐up in patients hospitalized with HF across all ejection fraction (EF) phenotypes. Methods and results: Consecutive patients hospitalized from December 2006 to December 2017 for HF with D‐dimer and EF values available (n = 1795) were enrolled. Associations between D‐dimer and all‐cause death were examined at 1‐year follow‐up. Median age was 57 years, 73.4% were male, and the majority (72.1%) were in New York Heart Association Classes III–IV. EF was reduced in 53.3% (HFrEF), mildly reduced in 16.3% (HFmrEF), and preserved in 30.4% (HFpEF). Median (interquartile range) D‐dimer on admission was 0.56 (0.27–1.295) μg/mL FEU (fibrinogen‐equivalent unit) in the whole cohort, 0.64 (0.28–1.48) μg/mL FEU in HFrEF, 0.50 (0.27–1.03) μg/mL FEU in HFmrEF, and 0.495 (0.25–1.10) μg/mL FEU in HFpEF (P = 0.001). At 1‐year follow‐up, higher D‐dimer (D‐dimer ≥0.56 μg/mL FEU) independently predicted all‐cause death in total cohort [hazard ratio (HR) 1.55; 95% confidence interval (CI), 1.15–2.1], in HFrEF (HR, 1.49; P = 0.039), and in HFpEF (HR, 2.06; P = 0.033). However, no relationship was found for HFrEF or HFmrEF when D‐dimer was treated as quartiles. In sensitivity analysis, quantitatively similar but more pronounced association between D‐dimer and all‐cause death was observed in total cohort and HFpEF cohort. Conclusions: In hospitalized HF patients, higher D‐dimer concentration was a significant and independent predictor of 1‐year all‐cause mortality. Across all HF phenotypes, this effect was most evident in HFpEF patients. [ABSTRACT FROM AUTHOR]

The construction of metallosupramolecules is an interesting but challenging topic for chemists. Dedicated design of multidentate ligands is an effective approach for the construction of novel lanthanide supramolecules. Herein, we report on the stepwise design and syntheses of two flexible and multidentate ligands H2L1 and H4L2 based on the o‐vanillin. By regulating the coordination sites and mode of the ligands, two novel DyIII‐based supramolecules, [Dy4Na(μ2‐OH)2L14(H2O)5(CH3OH)](CF3SO3)3 ⋅ 3H2O ⋅ CH3OH (Dy4) and [Dy8L24(H2L2)4(H2O)4] ⋅ 4CH3OH ⋅ 12H2O (Dy8), have been obtained. Structural studies reveal that Dy4 and Dy8 show different nuclearity and topology: Dy4 shows a crescent‐like structure coordinated by the ligands in different coordination fashions in which two ligands chelate DyIII forming {Dy2} units and linked by the other two ligands; Dy8 is obtained from the supramolecular assembly, in which four completely deprotonated ligands construct the {Dy2} units and the units are linked by four di‐deprotonated ligands, forming a macrocycle topology. Additionally, magnetic measurements reveal that the two complexes exhibit slow magnetic relaxation behavior. [ABSTRACT FROM AUTHOR]

Background: Red blood cell distribution width (RDW) and N‐terminal pro brain natriuretic peptide (NT‐proBNP) may predict the prognosis of heart failure (HF). However, the impact of combined RDW and NT‐proBNP levels as a prognostic marker of HF remains unclear and the significance of this combination at various time‐points has not been sufficiently studied. Hypothesis: RDW can predict prognosis in HF at various time‐points and combination with NT‐proBNP improves the prognostic value. Methods: Patients admitted to HF care unit of Fuwai Hospital CAMS&PUMC (Beijing, China) with a diagnosis of HF from November 2008 to November 2018 were analyzed retrospectively. Results: In total, 3231 patients with available RDW data at admission were evaluated (median age 58 years, 71.9% males, 39.7% coronary heart disease, 68.6% New York Heart Association [NYHA] III or IV). Median RDW and NT‐proBNP at admission were 13.4% (interquartile range [IQR]: 12.7%–14.5%), and 1723.00 pg/ml (IQR: 754.00–4006.25 pg/ml), respectively. During 2.9‐year median follow‐up, all‐cause death occurred in 1075 (33.27%) patients. Kaplan–Meier survival curve and Cox proportional‐hazard models, showed patients in the top quarter RDW had a 32.0% increased mortality compared to the bottom quarter (hazard ratio: 4.39, 95% confidence interval: 3.59–5.38; p <.001). The top quarter RDW retained independent prognostic value across HF with reduced ejection fraction [HFrEF], HF with mid‐range ejection fraction [HFmrEF], and HF with preserved ejection fraction [HFpEF] subgroups. Patients were subsequently divided into four groups by median RDW and NT‐proBNP. Comparison of Kaplan–Meier survival curves for various groups showed good risk stratification (p <.001). Conclusions: RDW is an independent predictor of mortality among patients with HF in the short‐, medium‐, and long‐term. Combination of RDW and NT‐proBNP improves the prognostic value. This is true across all clinical subtypes of heart failure (HFrEF, HFmrEF, HFpEF), and among most subgroups of patients with various comorbidities (infection, diabetes, hypertension). [ABSTRACT FROM AUTHOR]

With the development of multi‐energy technology, the electric‐heat integrated energy system has become an important research direction for multi‐energy joint supply. The dynamic characteristics and energy storage capacity of heat supply network provide potential for joint dispatching of electric heating energy system. Aiming at the problem of electric‐heat joint dispatching, this paper presents an operation optimization model of electric‐heat integrated energy system considering the virtual energy storage characteristics of heat supply network. Firstly, according to the characteristics of transmission delay and user temperature fuzzy, the virtual energy storage characteristics of heat supply network are studied, and a model of the dynamic transfer of energy in the heat system was built. Then, the operation optimization model of the electric‐heat integrated energy system is established to minimize the operation cost. In order to improve the robustness of scheduling optimization results, the Monte Carlo Simulation embedded Quantum Particle Swarm Optimization algorithm is proposed to solve the model. In order to prove the validity of the proposed model, this paper selects a park (a 36 node thermal system) in the northwest region of China as a simulation case. The results show that the operation optimization method considering the virtual energy storage of heat supply network will greatly enhance the complementary potential of the electric‐heat integrated energy system and reduce the operation cost of the system. [ABSTRACT FROM AUTHOR]

N‐ZIF‐(1:0)@NiCo‐LDH, N‐ZIF‐(1:3.5)@NiCo‐LDH and N‐ZIF‐(0:1)@NiCo‐LDH were prepared by mixing solvents in various volume ratios (Vmethanol:Vwater = 1:0, 1:3.5 and 0:1) when synthesizing precursors. These composite materials were characterized using scanning and transmission electron microscopies, X‐ray diffraction, X‐ray photoelectron spectroscopy and nitrogen adsorption–desorption measurements, and investigated as catalysts for reduction of 4‐nitrophenol, methyl orange and methylene blue. The NaBH4 concentration as an important factor that may affect catalytic activity for reduction of 4‐nitrophenol was examined. Under optimal experimental conditions, the excellent catalytic activity of the N‐ZIF‐(0:1)@NiCo‐LDH composite, compared to that of N‐ZIF‐(1:0)@NiCo‐LDH and N‐ZIF‐(1:3.5)@NiCo‐LDH composites, could be attributed to the presence of graphitic nitrogen. In addition, compared with previously reported catalysts, all catalysts prepared show excellent catalytic activity owing to the unique structure exposing more active sites. [ABSTRACT FROM AUTHOR]

Mesoporous catalyst S‐ZIF‐(1:2.5)@NixSy was prepared using ZIF‐(1:2.5) as a precursor. These composite materials were characterized by using scanning microscope (SEM), transmission electron microscopy(TEM), X‐ray diffraction (XRD), X‐ray photoelectron spectroscopy (XPS) and N2 adsorption‐desorption techniques, and studied as catalysts for the reduction of 4‐nitrophenol (4‐NP) to 4‐aminophenol (4‐AP), congo red (CR), methyl orange (MO), and methylene blue (MB). The BET specific surface area and pore volume of the catalyst were 167.49 m2/g and 0.32 m3/g respectively. The doping of S improves the catalytic performance of the catalyst. S‐ZIF‐(1:2.5)@NixSy showed an excellent catalytic rate (kapp = 22.3 × 10–3/s) in the experiment of reductive degradation of 4‐NP. In addition, S‐ZIF‐(1:2.5)@NixSy also showed good catalytic activity for the degradation of CR, MB, and MO, completing the catalytic reaction within 60, 60, and 90 s, respectively. The kapp values for CR, MB, and MO are 29.0 × 10–3/s, 44.0.0 × 10–3/s, and 29.2 × 10–3/s, respectively. [ABSTRACT FROM AUTHOR]

A peroxide‐mediated oxidation/radical addition/cyclization cascade reaction for the construction of isoquinoline skeleton is reported. The mild metal‐free promoted conditions of this reaction allowed us to synthesize a library of aromatic heterocycle‐substituted isoquinolines with a broad substrate scope, good functional group tolerance, and high atom economy in moderate to good yields. The radical intermediate in this reaction system was captured by TEMPO and confirmed by mass spectrometry (TOF‐MS). Further In vitro antiproliferative activities exhibited significant inhibition of the growth of HepG2, MCF‐7, MGC803 and EC‐9706 human cancer cell lines. [ABSTRACT FROM AUTHOR]

Since being discovered in 2008, the STING (stimulator of interferon genes) pathway has gradually been recognized as a central and promising target for immunotherapy. The STING pathway can be stimulated by cyclic dinucleotides (CDNs), leading to the type I interferons (IFN) production for immunotherapy for cancer or other diseases. However, the negative charges, hydrophilicity, and instability of CDNs have hindered their further applications. In addition, chronic activation of the STING pathway has been found to be involved in autoimmune diseases as IFN overproduction. Thus, research and development of STING agonists and inhibitors has been a hot field for the treatment of several diseases. The past several years, especially 2018, has seen increasingly rapid advances in this field. Here, this review summarizes the synthesis and modification of CDNs, the identification of nonnucleotide agonists, the recent progress in delivery systems and the medical applications, such as personalized vaccine adjuvants, in detail. In addition, in this review, we summarize the STING inhibitors' advances from two aspects, covalent, and noncovalent inhibitors. [ABSTRACT FROM AUTHOR]

The competition between cocrystallization and separated crystallization in a solvent was explored via X‐ray diffraction and high‐performance liquid chromatography methods in different solvents and by considering the solvent evaporation rate. The results revealed that the solvent system and solvent evaporation rate can affect the nucleation order of the cocrystal and coformers in the solution. In fact, solubility tests in different solvents confirmed that the solubility plays a key role in the cocrystal formation process. Furthermore, the width of the metastable zone influenced the solute nucleation order and was a decisive factor in the cocrystal formation process when the solvent evaporation rate was varied. Cocrystals could therefore be obtained by adjusting the solvents and solvent evaporation rate. The preparation of kinetic 2,4,6,8,10,12‐hexanitrohexaazaisowurtzitane–2,4,6‐trinitrophenol cocrystals via rapid solvent evaporation proves the practicability of this theory. [ABSTRACT FROM AUTHOR]

Abstract: The magnetic relaxation and magnetization blocking barriers of tailor‐made homo‐ and heterodinuclear compounds [Dy2(opch)2(OAc)2(H2O)2]⋅MeOH (1) and [DyMn(opch)2(OAc)(MeOH)(H2O)2] (2), where H2opch is (E)‐N′‐(2‐hydroxy‐3‐methoxybenzylidene)pyrazine‐2‐carbohydrazide, were systematically investigated and the change in single‐molecule magnet behavior originating from targeted replacement of one dysprosium site in the Dy2 compound with manganese was elucidated through a combination of experimental and theoretical studies. A detailed comparative study on these closely related model compounds revealed remarkable changes of the crystal‐field splitting and anisotropy of the Dy site and the total exchange spectrum due to the replacement of Dy by Mn. The blocking barriers of these two compounds, which explain their different relaxation behaviors, were analyzed. The two Ising doublets arising from the magnetic interaction in the case of 1 are strongly uniaxial, with tunneling splittings smaller than 10−6 cm−1, and this leads to magnetic relaxation at temperatures exceeding the exchange energy (2.14 cm−1), which involves transition via the excited states corresponding to local transitions on the excited doublet at the Dy site. The third and fourth exchange doublets in 2 (located at 2.16 and 3.25 cm−1, respectively) show much larger tunneling splittings (of 10−4 and 10−3 cm−1, respectively), and thus open an important path for magnetic relaxation. [ABSTRACT FROM AUTHOR]

Two types of magnetic nanocomposites, Co-carbon composite (Co@C) and Zn/Co-carbon composite (Zn/Co@C), were synthesized by one-step calcinations of hollow Co-ZIF (ZIF-67) and Zn/Co-ZIF (ZIF-67@ZIF-8) (ZIF = zeolitic imidazolate framework), as well as applied as adsorbents in the reduction of Rhodamine B (RhB). The prepared composites were carefully analyzed by SEM, TEM-EDXS (EDXS = energy-dispersive X-ray specroscopy), XRD, SQUID, and nitrogen adsorption/desorption measurements. Co@C and Zn/Co@C showed the maximum adsorption capacities of 48 mg g-1 and 101.93 mg g-1, respectively, toward RhB. The adsorption isotherms of RhB on the Zn/Co@C nanocomposites were well fitted with the Langmuir model, and the pseudo-second-order model accurately describes the adsorption kinetic process for the adsorption of RhB on the materials. The results show that the composite materials of Zn/Co@C possess higher porosity and magnetic properties and exhibit higher adsorption capacity, convenient separation ability, along with good reusability of the adsorbent. The theoretical calculations also clarify that RhB on the distorted Co-Zn surface is much more stable than that on Co(111), in good agreement with the experimental observations. [ABSTRACT FROM AUTHOR]

The self-assembly of three giant hexagonal 3d-4f metallocycles with inner diameters of 16.4, 16.5, and 16.4 Å, is described. Hexagonal metallocycles were stacked along the crystallographic c axis, producing unique hexagonal macroscopic tubular single crystals. The assembly mechanism of the tubular crystals was investigated. Remarkably, all three hexagonal metallocycles show typical single-molecule magnet behavior, benefiting from the ferromagnetic couplings between the 3d and 4f ions. [ABSTRACT FROM AUTHOR]

The self-assembly of three giant hexagonal 3d-4f metallocycles with inner diameters of 16.4, 16.5, and 16.4 Å, is described. Hexagonal metallocycles were stacked along the crystallographic c axis, producing unique hexagonal macroscopic tubular single crystals. The assembly mechanism of the tubular crystals was investigated. Remarkably, all three hexagonal metallocycles show typical single-molecule magnet behavior, benefiting from the ferromagnetic couplings between the 3d and 4f ions. [ABSTRACT FROM AUTHOR]

Elaborate chemical design is of utmost importance in order to slow down the relaxation dynamics in single-molecule magnets (SMMs) and hence improve their potential applications. Much interest was devoted to the study of distinct relaxation processes related to the different crystal fields of crystallographically independent lanthanide ions. However, the assignment of the relaxation processes to specific metal sites remains a challenging task. To address this challenge, a new asymmetric Dy2 SMM displaying a well-separated two-step relaxation process with the anisotropic centers in fine-tuned local environments was elaborately designed. For the first time a one-to-one relationship between the metal sites and the relaxation processes was evidenced. This work sheds light on complex multiple relaxation and may direct the rational design of lanthanide SMMs with enhanced magnetic properties. [ABSTRACT FROM AUTHOR]

The reaction of the rigid polydentate Schiff-base H3L with different dysprosium carboxylates afforded two novel centrosymmetrical dinuclear DyIII compounds, [Dy2(HL)2-(CH3COO)2(DMF)2] (1) and [Dy2(HL)2(PhCOO)2(DMF)2]. 4DMF (2) with differing carboxylate groups. The two differing carboxylate groups affect the magnetic interaction and/or local anisotropy of the Dy ion, and therefore we have two compounds showing dissimilar magnetic behaviour. The acetato bridging groups with a syn-syn η1:η1:μ2 mode in compound 1 lead to the disappearance of slow magnetic relaxation under zero dc field. Nevertheless, typical SMM behaviour is observed for compound 2 with η2-chelating benzoate ligands. [ABSTRACT FROM AUTHOR]

Three pairs of enantiopure chiral triangular Ln3 clusters, [Ln3L RRRRRR/SSSSSS(μ3-OH)2(H2O)2(SCN)4]⋅ xCH3OH⋅ yH2O ( R -Dy3, Ln=Dy, x=6, y=0; S -Dy3, Ln=Dy, x=6, y=1; R -Ho3, Ln=Ho, x=6, y=1; S -Ho3, Ln=Ho, x=6, y=1; R -Er3, Ln=Er, x=6, y=0; S -Er3, Ln=Er, x=6, y=1), have been successfully synthesized by a rational enantioselective synthetic strategy. The core of triangular Ln3 is bound in the central N6O3 of the macrocyclic ligand, and the coordination spheres of Ln ions are completed by four SCN− anions and two H2O molecules in axial positions of the macrocycle. The circular dichroism (CD) and vibrational circular dichroism (VCD) spectra of the enantiomers demonstrate that the chirality is successfully transferred from the ligands to the resulting Ln3 clusters. Ac susceptibility measurements reveal that single-molecule magnet behavior occurs for both enantiopure clusters of R -Dy3 and S -Dy3. This work is one of the few examples of the successful design of a pair of triangular Dy3 clusters showing simultaneously slow magnetic relaxation and optical activity, and this might open up new opportunities to develop novel multifunctional materials. [ABSTRACT FROM AUTHOR]

Two new 'butterfly-shaped' pentanuclear dysprosium(III) clusters, [Dy5(μ3-OH)3(opch)6(H2O)3] ⋅3 MeOH ⋅ 9 H2O ( 1) and [Dy5(μ3-OH)3(Hopch)2(opch)4(MeOH)(H2O)2] ⋅(ClO4)2 ⋅ 6 MeOH ⋅4 H2O ( 2), which were based on the heterodonor-chelating ligand o-vanillin pyrazine acylhydrazone (H2opch), have been successfully synthesized by applying different reaction conditions. Single-crystal X-ray diffraction analysis revealed that the butterfly-shaped cores in both compounds were comparable. However, their magnetic properties were drastically different. Indeed, compound 1 showed dual slow-relaxation processes with a transition between them that corresponded to energy gaps (Δ) of 8.1 and 37.9 K and pre-exponential factors ( τ0) of 1.7×10−5 and 9.7×10−8 s for the low- and high-temperature domains, respectively, whilst only a single relaxation process was noted for compound 2 (Δ=197 K, τ0=3.2×10−9 s). These significant disparities are most likely due to the versatile coordination of the H2opch ligands with particular keto-enol tautomerism, which alters the strength of the local crystal field and, hence, the nature or direction of the easy axes of anisotropic dysprosium ions. [ABSTRACT FROM AUTHOR]

Two Dy compounds, [Dy4(μ4-O)L2(C6H5COO)6] ·3CH3OH ( 1) and [Dy2L(H2L)(teaH2)(o-vanillin)(H2O)](ClO4)2 ·2CH3OH ·H2O ( 2, teaH3 = triethanolamine), were assembled by the reactions of the salen-type ligand N, N′-bis(3-methoxysalicylidene)-1,2-cyclohexanediamine (H2L) and different dysprosium salts and bases. These compounds show both local chirality and slow magnetic relaxation. The former is induced by an unprecedented coordination mode of the ligand H2L, in which the N2O2 pocket encapsulates one Dy ion. Compound 1, which has four Dy ions in distinct coordination environments, demonstrates the rare Dy4 tetrahedron motif supported by a central μ4-O atom, which is akin to a chiral carbon atom in organic molecules, as revealed by single-crystal X-ray analyses. In contrast, the formation of 2, which shows an unusual structural motif with a tail, is driven by the presence of triethanolamine. In spite of the low-symmetry coordination geometry around each Dy ion, both compounds display slow magnetic relaxation behavior, but with fast quantum tunneling relaxation, as indicated by alternating current (ac) susceptibility measurements. [ABSTRACT FROM AUTHOR]

A linear tetranuclear 3d-4f Co2Dy2 cluster assembled from a polydentate Schiff base exhibits single-molecule magnet (SMM) behavior with an anisotropic barrier of 33.8 K. Due to the presence of diamagnetic cobalt(III) ions, the tetranuclear cluster of 1 behaves magnetically like a dinuclear Dy2 system. However, the diamagnetic segment might efficiently minimize undesirable intermolecular magnetic interactions, thereby improving the performance of the SMM behavior of 1. This discrete complex presents us with a unique opportunity to study the magnetic properties and to probe the dynamics of magnetization in a magnetically isolated Dy2 system. [ABSTRACT FROM AUTHOR]