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In this study, a simple and portable electrochemical sensor based on laser-induced graphene (LIG) has been developed to systematically investigate the feasibility of LIG as an electrode to detect organophosphorus pesticides (OPs). It proves that the LIG-based electrode has a relatively high electrochemically active surface area (ECSA) and heterogeneous electron transfer (HET) of 0.100 cm2 and 0.000825 cm s−1, respectively. In addition, zirconium dioxide nanoparticles (ZrO2 NPs) have been modified on the electrode with three different binders, β-cyclodextrin (β-CD), chitosan (CS) and Nafion, to improve the adsorption capacity of the electrode toward OPs, and the effect of the binders on the performance of the as-fabricated sensor has been investigated in detail. The results show that β-CD increases not only the electrochemically active surface area of the electrode but also the redox peak current of methyl parathion (MP). To evaluate the sensitivity of the sensor, differential pulse voltammetry (DPV) curves have been tested in solutions containing different concentrations of MP using ZrO2-β-CD/LIG as an electrode, which shows a detection range of 5–200 ng ml−1 and a detection limit of 0.89 ng ml−1. In summary, the LIG-based sensor has a low detection limit, high sensitivity and good interference resistance, and thus has tremendous potential for the detection of pesticides in the environment. [ABSTRACT FROM AUTHOR]

Folic acid (FA), as a water-soluble vitamin B compound, plays an irreplaceable role in human health. It is crucial to detect FA in a rapid, efficient, and sensitive way. In the current study, we constructed a fluorescence coordination polymer (CP) from TbIII and pyridine-2,6-dicarboxylic acid (H2pda) to detect folic acid. Single crystal X-ray diffraction indicated that the complex contained a one-dimensional (1D) double-chain structure, which assembled into a three-dimensional (3D) supramolecular framework via the inter-chain hydrogen bonds. Interestingly, the crystal size of the complex was optimized up to 2.4 mm through L9(34) orthogonal experiments. The complex exhibited typical TbIII fluorescence, which could detect FA with high detection sensitivity (LOD = 0.22 μM), an excellent anti-interference ability, and remarkable recyclability in aqueous solution through fluorescence quenching of the emission spectra. Fluorescence quenching is related to the competition absorption (CA) and photoinduced electron transfer (PET) process between the complex and FA, which is inspected by density functional theory (DFT) calculations. [ABSTRACT FROM AUTHOR]

Targeted approaches for manipulating the coordination geometry of lanthanide ions are a promising way to synthesize high-performance single-molecule magnets (SMMs), but most of the successful examples reported to date focus on mononuclear complexes. Herein, we describe a strategy to assemble dinuclear SMMs with DyIII ions in approximate D5h coordination geometry based on pyrazolate-based macrocyclic ligands with two binding sites. A Dy4 complex with a rhomb-like arrangement of four DyIII as well as two dinuclear complexes having axial chlorido ligands (Dy2·Cl and Dy2*·Cl) were obtained; in the latter case, substituting Cl− by SCN− gave Dy2·SCN. Magneto-structural studies revealed that the μ-OH bridges with short Dy–O bonds dominate the magnetic anisotropy of the DyIII ions in centrosymmetric Dy4 to give a vortex type diamagnetic ground state. Dynamic magnetic studies of Dy4 identified two relaxation processes under zero field, one of which is suppressed after applying a dc field. For complexes Dy2·Cl and Dy2*·Cl, the DyIII ions feature almost perfect D5h environment, but both complexes only behave as field-induced SMMs (Ueff = 19 and 25 K) due to the weak axial Cl− donors. In Dy2·SCN additional MeOH coordination leads to a distorted D2d geometry of the DyIII ions, yet SMMs properties at zero field are observed due to the relatively strong axial ligand field provided by SCN− (Ueff = 43 K). Further elaboration of preorganizing macrocyclic ligands appears to be a promising strategy for imposing a desired coordination geometry with parallel orientation of the anisotropy axes of proximate DyIII ions in a targeted approach. [ABSTRACT FROM AUTHOR]

A novel and air-stable organo(hydro)diborane featuring a five-membered aryl ring supported bridging B–C–B three-centre–two-electron (3c–2e) bond has been reported. Pyrido[1,2-a]isoindole was found to undergo a stepwise BH3 addition reaction, during which a mono-BH3 adduct was formed from a electrophilic addition at the Cγ in pyrido[1,2-a]isoindole. A molecule of hydrogen was eliminated throughout the second step of addition reaction. DFT calculations indicate that the H2 evolution is concerted to the second BH3 addition rather than forming B＝C before the second BH3 attack. [ABSTRACT FROM AUTHOR]

By using a crab-like hydrazone ligand, dinuclear and tetranuclear dysprosium-based complexes Dy2 and Dy4 have been isolated. Magnetic investigation reveals that complex Dy2 shows typical single-molecule magnet behavior under a zero field, benefiting from the ferromagnetic coupling between the DyIII ions, while Dy4 possesses a diamagnetic ground state with the anisotropy axes of DyIII ions in centripetal arrangement. The magnetic anisotropies and couplings were confirmed by ab initio calculations. [ABSTRACT FROM AUTHOR]

The anion-adaptive self-assembly described here not only offers a facile approach to produce large single-molecule magnets without the need for precise manipulation of the stoichiometry of ligand–metal centers but also provides an understanding of how structural factors affect the magnetic properties. X-ray diffraction analysis reveals that a rare hexagonal metallacycle with a diameter approaching 23 Å was obtained. Magnetic investigation shows that the resulting hexagonal metallacycle behaves as a typical single-molecule magnet with double relaxation under dc field thanks to the different coordination geometry of the DyIII centers. [ABSTRACT FROM AUTHOR]

A hexanuclear cluster [(Cp*Dy)6K4Cl16(THF)6], [Cp*Dy]6, has been constructed from six {Cp*DyIII} synthons in which the strongly coordinating Cp*− caps determine the local anisotropy axes. Structural characterization of [Cp*Dy]6 shows two almost parallel triangular (Cp*Dy)3 fragments that are linked by the K+ and Cl− ions. Magnetic measurements reveal slow thermal relaxation and fast quantum tunneling relaxation in the absence of an external dc field. After applying a weak dc field, the quantum tunneling relaxation is efficiently suppressed, giving a sizable energy barrier of 561 K, which represents the current record energy barrier for high nuclearity organometallic SMMs. [ABSTRACT FROM AUTHOR]

Despite increasing attention being focused on traditional polymer-based LCST systems, only a limited number of LCST systems induced by small molecules have been investigated. In this paper, we developed a series of new thermo-responsive small molecules with crown ether units as the thermo-sensitive cores. The diversity in the crown ether structures fully demonstrates the differences in water solubility and LCST properties. Due to the competition between the supramolecular recognition process induced by the size-matching selectivity and the salting-out effect caused by cation–water–crown ether solvation, controllable and programmable thermo-responsive properties are realized. [ABSTRACT FROM AUTHOR]

Structurally unique double-shelled 4f and 3d–4f supramolecular grids were constructed and assembled into 3D hydrogen-bonded organic frameworks (HOFs), with the 3d–4f heterometallic HOF showing single-molecule magnet (SMM) behaviour. [ABSTRACT FROM AUTHOR]

Toroidal arrangements of magnetic moments are realized in heterometallic Ln6Cu6 (Ln = Tb and Dy) macrocycles thanks to the magnetic coupling between lanthanide and 3d metal ions. [ABSTRACT FROM AUTHOR]

Geometry and magnetic interaction modulations in a series of dinuclear dysprosium compounds, [Dy2Lz2(OAc)6]·2CH3OH (1), [Dy2Lz2(C6H5CO2)6]·2CH3CN (2), and [Dy2L2(SO3CF3)4THF4] (3) (Lz = 6-pyridin-2-yl-[1,3,5]triazine-2,4-diamine; L = N-(2,3-dimethylbut-3-en-2-yl)-N-hydroxynitrous amide; THF = tetrahydrofuran), can effectively tune the relaxation dynamics of magnetization. The dysprosium centres of compounds 2 and 3 display a hula hoop-like geometry; however, those in 1 show the monocapped square antiprismatic geometries. Moreover, the Dy2 cores of compounds 1 and 3 were linked by μ2–η1:η1 and μ2–η1:η2 bridging modes, thus generating shorter intramolecular Dy…Dy distances as compared to those in compound 2. Consequently, these three compounds demonstrate distinct magnetic properties. Compounds 1 and 2 behave as single-molecule magnets (SMMs) under an appropriate static dc field; in addition, 2 displays field-induced multiple relaxation processes under a 1000 Oe dc field. Compound 3 shows a high relaxation energy barrier of 102 K in the zero dc field. These three interesting compounds with Dy2 cores shed light on the coordination geometry and magnetic interactions for the modulation of the properties of SMMs. [ABSTRACT FROM AUTHOR]

A rare end-to-end azido-pinned interlocking lanthanide square was self-assembled using a ditopic Schiff-base (H2L) and NaN3 as ligands. Obvious ferromagnetic interaction and a record anisotropy barrier of 152(4) K among lanthanide azido-bridged SMMs in a zero dc field were observed. [ABSTRACT FROM AUTHOR]

Three μ4-O bridged Dy4 squares, {[Dy4(μ4-O)(HL1)4(H2O)4]2(NO3)3(OH)}·2H2O·2CH3OH (1), [Dy4(μ4-O)(HL2)4(SCN)2]·2H2O·4CH3OH (2) and [Dy4(μ4-O)(H2L3)2(SCN)2]·6H2O (3) were assembled by using a Schiff base ligand and its dimerized and reduced congener, respectively. These complexes share a similar μ4-O bridged Dy4 core, while, both the coordination geometry and metal–ligand interactions are slightly changed upon the modulation of the ligands, resulting in distinct single-molecular magnetic (SMM) and single-molecular toroic (SMT) properties. In complex 1, the Schiff base ligands are in an antiparallel fashion and all DyIII ions are in a similar coordination geometry, realizing the toroidal arrangement of magnetic moments. For complex 2, the reduced ligand H3L2 in a parallel fashion results in double relaxation processes and a 9-fold increase of the Ueff. Interestingly, with the use of the dimerized ligand H6L3, we obtained complex 3, which is similar to complex 2, while due to the slight changes of the coordination environment both the single molecular magnetic property and toroidal magnetic moments almost disappeared. [ABSTRACT FROM AUTHOR]

Two new dysprosium complexes, [Dy(H5L)(NO3)2(CH3OH)2]·4CH3OH (1) and [Dy2(H5L)2(NO3)4(H2O)2]·10CH3OH (2), were isolated from the reaction of a novel 1,8-naphthalenediol-based ligand N,N′-((1,8-dihydroxynaphthalene-2,7-diyl)bis(methanylylidene))bis(2-hydroxybenzohydrazide), H6L with dysprosium(iii) nitrate upon crystallization at different temperatures. Because of a low-symmetrical coordination environment, both complexes display only field-induced single molecular magnetic (SMM) behavior. Interestingly, complex 2 containing two dysprosium ions shows field-induced multiple relaxation processes, whereas only one relaxation process is observed for complex 1. The remarkably different behavior observed in 2 is mainly ascribed to the weak intra- or intermolecular interactions between the two DyIII centres in this complex. [ABSTRACT FROM AUTHOR]

A unique Dy6 complex with a planar Dy3 + Dy3 structure was assembled by delicately modifying the axial ligands. Single-molecule magnet behavior and meanwhile a toroidal magnetic moment in the ground state have been observed. [ABSTRACT FROM AUTHOR]

An unprecedented octanuclear dysprosium(iii) cluster with the formula [Dy8L6(μ3-OH)4(μ2-CH3O)2(CH3OH)6(H2O)2]·6H2O·10CH3OH·2CH3CN (1) based on a nonlinearly tritopic aroylhydrazone ligand H3L has been isolated, realizing the successful linking of pairwise interesting triangular Dy3 SMMs. It is noteworthy that two enantiomers (Λ and Δ configurations) individually behaving as a coordination-induced chirality presented in the Dy3 helicate are connected in the meso Dy8 cluster. Remarkably, alternating-current magnetic susceptibility measurements revealed that the Dy8 cluster shows typical SMM behavior inherited from its Dy3 helical precursor. It is one of the rare polynuclear Lnn SMMs (n ＞ 7) under zero dc field. [ABSTRACT FROM AUTHOR]

Recently, considerable research efforts have focused on increasing the biocompatibility and bactericidal activity of biomedical polymeric devices (e.g., catheters, etc.) through incorporation of nitric oxide (NO) releasing molecules. NO is an important endogenous molecule that is well known for enhancing blood flow via its vasodilatory activity, but it also exhibits potent antithrombotic and antimicrobial properties. In this work, we demonstrate that silicone rubber tubing can be impregnated with a tertiary S-nitrosothiol (RSNO), S-nitroso-tert-dodecylmercaptan, via a simple solvent swelling method. We further characterize the NO release and RSNO leaching from the tubing over time via use of chemiluminescence and UV/Vis spectroscopy, respectively. The tubing is shown to maintain an NO flux above the physiological levels released by endothelial cells, 0.5–4.0 × 10−10 mol cm−2 min−1, for more than 3 weeks while stored at 37 °C and exhibit minimal leaching. Finally, the RSNO impregnated tubing exhibits significant antimicrobial activity over a 21 d period (vs. controls) during incubation in a CDC bioreactor after inoculation of media with S. aureus bacteria. The use of such lipophilic RSNO impregnated silicone rubber tubing could dramatically reduce the risk of catheter-related infections, which are a common problem associated with placement of intravascular or urinary catheters. [ABSTRACT FROM AUTHOR]

Two unique Dy6 complexes with fascinating Dy3 + Dy3 structures were assembled, showing single-molecule magnetic behavior with high energy barriers of 116 and 181 K for Dy6–NO3 and Dy6–SCN. [ABSTRACT FROM AUTHOR]

The first supramolecular 3d–4f grid was constructed using novel dihydrazone based ligands. [ABSTRACT FROM AUTHOR]

A family of [RE2M2L2(BA)6] (RE = Gd, Tb, Dy, Y; M = Co, Ni, Cu, Zn; L = 1,2-bis(2-hydroxy-3-methoxybenzylidene)hydrazine; BA = benzoic acid) complexes were synthesized and structurally and magnetically characterized. The magnetic interactions between spin centers were systematically investigated. The interactions of M–M (M = Co, Ni and Cu) and Gd–Ni/Cu were extracted from the fitting of the experimental data of Y2M2 (M = Co, Ni and Cu) and Gd2M2 (M = Ni and Cu) derivatives, respectively. Furthermore, the Ln–M interactions were qualitatively analyzed by deducting the M–M coupling and the contribution of the crystal-field effects of the LnIII ion from the total magnetic susceptibility of Ln2M2 (Ln = Dy and Tb) compounds. In addition, complex [Dy2Zn2L2(BA)6] shows field induced single molecular magnet behavior profiting from the isolated anisotropic dysprosium ions. [ABSTRACT FROM AUTHOR]

Dicycloplatin is a new generation supramolecular platinum-containing anti-cancer drug. Due to its structure, it is difficult to differentiate dicycloplatin from physical mixtures of carboplatin and cyclobutane dicarboxylate, and confounding results may arise during drug characterization. To solve this problem, this study aims to provide a reliable and reproducible standard for the determination of dicycloplatin. A simple method for dicycloplatin quality control has been developed using X-ray powder diffraction (XRPD) and high performance liquid chromatography (HPLC). XRPD allowed the control of impurities and dissociation of the dicycloplatin active ingredient to less than 1%, and HPLC allowed the monitoring and control of the relative molar ratio of carboplatin and cyclobutane dicarboxylate within the purity range. The study proved for the first time that the dicycloplatin supramolecule is substantially different from a physical mixture of carboplatin and cyclobutane dicarboxylate. [ABSTRACT FROM AUTHOR]

The initial employment of N1,N2,N3,N4-tri(3-methoxysalicylidene) triethylenetetraamine ligand (H3L, SCHEMREFScheme 1/SCHEMREF) in lanthanide coordination chemistry for single molecule magnets has yielded a new family of dinuclear LnIII2 compounds with the general formula of [Ln2(L)2]·nCH3CN (Ln = Gd (1), Tb (2) with n = 0, Ln = Dy (3) with n = 4). These three complexes have been structurally and magnetically characterized. The structural analyses reveal that they are isomorphous dinuclear complexes where the Ln2 entities were encapsulated by two polydentate Schiff base ligands. Variable-temperature magnetic susceptibility studies indicate the presence of dominant antiferromagnetic interactions in complexes 2 and 3, whereas complex 1 containing isotropic Gd ions allows the quantification of the antiferromagnetic interaction with JGd–Gd = −0.041 cm−1. Dynamic measurements reveal that 3 displays single-molecule magnet behaviour with an activation energy barrier Δ = 18.9 K and pre-exponential factor τ0 = 3.92 × 10−6 s, while 1 and 2 do not show any out-of-phase ac susceptibility signals. [ABSTRACT FROM AUTHOR]

In this study, a simple and portable electrochemical sensor based on laser-induced graphene (LIG) has been developed to systematically investigate the feasibility of LIG as an electrode to detect organophosphorus pesticides (OPs). It proves that the LIG-based electrode has a relatively high electrochemically active surface area (ECSA) and heterogeneous electron transfer (HET) of 0.100 cm 2 and 0.000825 cm s -1 , respectively. In addition, zirconium dioxide nanoparticles (ZrO 2 NPs) have been modified on the electrode with three different binders, β-cyclodextrin (β-CD), chitosan (CS) and Nafion, to improve the adsorption capacity of the electrode toward OPs, and the effect of the binders on the performance of the as-fabricated sensor has been investigated in detail. The results show that β-CD increases not only the electrochemically active surface area of the electrode but also the redox peak current of methyl parathion (MP). To evaluate the sensitivity of the sensor, differential pulse voltammetry (DPV) curves have been tested in solutions containing different concentrations of MP using ZrO 2 -β-CD/LIG as an electrode, which shows a detection range of 5-200 ng ml -1 and a detection limit of 0.89 ng ml -1 . In summary, the LIG-based sensor has a low detection limit, high sensitivity and good interference resistance, and thus has tremendous potential for the detection of pesticides in the environment.

In situ metal-templated (hydrazone) condensation also called subcomponent self-assembly of 4,6-dihydrazino-pyrimidine, o -vanillin and dysprosium ions resulted in the formation of discrete hexa- or dodecanuclear metallosupramolecular Dy 6 (L) 6 or Dy 12 (L) 8 aggregates resulting from second-order template effects of the base and the lanthanide counterions used in these processes. XRD analysis revealed unique circular helical or tetragonal bipyramid architectures in which the bis(hydrazone) ligand L adopts different conformations and shows remarkable differences in its mode of metal coordination. While a molecule of trimethylamine acts as a secondary template that fills the void of the Dy 6 (L) 6 assembly, sodium ions take on this role for the formation of heterobimetallic Dy 12 (L) 8 by occupying vacant coordination sites, thus demonstrating that these processes can be steered in different directions upon subtle changes of reaction conditions. Furthermore, Dy 6 (L) 6 shows an interesting spin-relaxation energy barrier of 435 K, which is amongst the largest values within multinuclear lanthanide single-molecular magnets., Competing Interests: The authors declare no conflict of interest., (This journal is © The Royal Society of Chemistry.)

Targeted approaches for manipulating the coordination geometry of lanthanide ions are a promising way to synthesize high-performance single-molecule magnets (SMMs), but most of the successful examples reported to date focus on mononuclear complexes. Herein, we describe a strategy to assemble dinuclear SMMs with Dy III ions in approximate D 5h coordination geometry based on pyrazolate-based macrocyclic ligands with two binding sites. A Dy4 complex with a rhomb-like arrangement of four Dy III as well as two dinuclear complexes having axial chlorido ligands (Dy2·Cl and Dy2*·Cl) were obtained; in the latter case, substituting Cl - by SCN - gave Dy2·SCN. Magneto-structural studies revealed that the μ-OH bridges with short Dy-O bonds dominate the magnetic anisotropy of the Dy III ions in centrosymmetric Dy4 to give a vortex type diamagnetic ground state. Dynamic magnetic studies of Dy4 identified two relaxation processes under zero field, one of which is suppressed after applying a dc field. For complexes Dy2·Cl and Dy2*·Cl, the Dy III ions feature almost perfect D 5h environment, but both complexes only behave as field-induced SMMs ( U eff = 19 and 25 K) due to the weak axial Cl - donors. In Dy2·SCN additional MeOH coordination leads to a distorted D 2d geometry of the Dy III ions, yet SMMs properties at zero field are observed due to the relatively strong axial ligand field provided by SCN - ( U eff = 43 K). Further elaboration of preorganizing macrocyclic ligands appears to be a promising strategy for imposing a desired coordination geometry with parallel orientation of the anisotropy axes of proximate Dy III ions in a targeted approach.

A novel and air-stable organo(hydro)diborane featuring a five-membered aryl ring supported bridging B-C-B three-centre-two-electron (3c-2e) bond has been reported. Pyrido[1,2- a ]isoindole was found to undergo a stepwise BH 3 addition reaction, during which a mono-BH 3 adduct was formed from a electrophilic addition at the C γ in pyrido[1,2- a ]isoindole. A molecule of hydrogen was eliminated throughout the second step of addition reaction. DFT calculations indicate that the H 2 evolution is concerted to the second BH 3 addition rather than forming BC before the second BH 3 attack.

A hexanuclear cluster [(Cp*Dy) 6 K 4 Cl 16 (THF) 6 ], [Cp*Dy] 6 , has been constructed from six {Cp*Dy III } synthons in which the strongly coordinating Cp* - caps determine the local anisotropy axes. Structural characterization of [Cp*Dy] 6 shows two almost parallel triangular (Cp*Dy) 3 fragments that are linked by the K + and Cl - ions. Magnetic measurements reveal slow thermal relaxation and fast quantum tunneling relaxation in the absence of an external dc field. After applying a weak dc field, the quantum tunneling relaxation is efficiently suppressed, giving a sizable energy barrier of 561 K, which represents the current record energy barrier for high nuclearity organometallic SMMs.

We report for the first time the ability to direct and control the migration path of silver nanoparticles across graphene oxide (GO). With the help of a focused laser beam, we demonstrated choreographed nanoparticle assembly on GO via a directed electric-field. Silver migration and the resultant dendrite formation on GO were characterized through electrical testing coupled with fluorescence microscopy. The proposed mechanism for silver migration in GO involves the interlayer water between GO sheets serving as the electrolyte for the electrochemical process. This interlayer water facilitates the disappearance of dendrites through oxidation and dissolution into the water. Furthermore, we demonstrate that the shape of the formed Ag dendrites can be controlled by a combination of an applied electric field and patterned regions of a reduced GO film created by a focused laser beam. This paves the way for an alternative low-cost silver nanoparticle assembly method requiring only a low-powered laser and low voltage., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

Fluorinated polymers are widely used as biomaterials in various biomedical implant and device applications. However, thrombogenicity, surface-induced inflammation, and risk of microbial infection remain key issues that can limit their use. In this work, we describe the first nitric oxide (NO) releasing fluorinated polymer, in which a new fluorinated NO donor, S -nitroso- N -pentafluoropropionylpenicillamine (C 2 F 5 -SNAP), is incorporated within the polyvinylidene fluoride (PVDF) tubing. The synthesis, decomposition kinetics, and NO-release characteristics of the C 2 F 5 -SNAP species are described in detail. Then, using a simple solvent swelling method, we demonstrate that C 2 F 5 -SNAP can readily be doped into PVDF tubing. The resulting tubing can release NO for 11 days under physiological conditions, with an NO flux > 0.5 × 10 -10 mol/cm 2 ·min over the first 7 days. Due to fluorous-fluorous interactions, the leaching of the fluorinated NO donor and its decomposed products is shown to be very low (less than 5 nmol/mg, total). Further, the new NO-releasing PVDF tubing exhibits significant antimicrobial activity (compared to undoped PVDF tubing) against both gram positive and negative S. aureus and P. aeruginosa bacterial strains over a 7 d test period. This new NO-releasing fluorinated polymer is likely to have the potential to improve the biocompatibility and antimicrobial activity of various biomedical devices., Competing Interests: Conflicts of interest The authors declare no competing financial interest.

Geometry and magnetic interaction modulations in a series of dinuclear dysprosium compounds, [Dy 2 Lz 2 (OAc) 6 ]·2CH 3 OH (1), [Dy 2 Lz 2 (C 6 H 5 CO 2 ) 6 ]·2CH 3 CN (2), and [Dy 2 L 2 (SO 3 CF 3 ) 4 THF 4 ] (3) (Lz = 6-pyridin-2-yl-[1,3,5]triazine-2,4-diamine; L = N-(2,3-dimethylbut-3-en-2-yl)-N-hydroxynitrous amide; THF = tetrahydrofuran), can effectively tune the relaxation dynamics of magnetization. The dysprosium centres of compounds 2 and 3 display a hula hoop-like geometry; however, those in 1 show the monocapped square antiprismatic geometries. Moreover, the Dy 2 cores of compounds 1 and 3 were linked by μ 2 -η 1 :η 1 and μ 2 -η 1 :η 2 bridging modes, thus generating shorter intramolecular DyDy distances as compared to those in compound 2. Consequently, these three compounds demonstrate distinct magnetic properties. Compounds 1 and 2 behave as single-molecule magnets (SMMs) under an appropriate static dc field; in addition, 2 displays field-induced multiple relaxation processes under a 1000 Oe dc field. Compound 3 shows a high relaxation energy barrier of 102 K in the zero dc field. These three interesting compounds with Dy 2 cores shed light on the coordination geometry and magnetic interactions for the modulation of the properties of SMMs.

Three μ 4 -O bridged Dy 4 squares, {[Dy 4 (μ 4 -O)(HL 1 ) 4 (H 2 O) 4 ] 2 (NO 3 ) 3 (OH)}·2H 2 O·2CH 3 OH (1), [Dy 4 (μ 4 -O)(HL 2 ) 4 (SCN) 2 ]·2H 2 O·4CH 3 OH (2) and [Dy 4 (μ 4 -O)(H 2 L 3 ) 2 (SCN) 2 ]·6H 2 O (3) were assembled by using a Schiff base ligand and its dimerized and reduced congener, respectively. These complexes share a similar μ 4 -O bridged Dy 4 core, while, both the coordination geometry and metal-ligand interactions are slightly changed upon the modulation of the ligands, resulting in distinct single-molecular magnetic (SMM) and single-molecular toroic (SMT) properties. In complex 1, the Schiff base ligands are in an antiparallel fashion and all Dy III ions are in a similar coordination geometry, realizing the toroidal arrangement of magnetic moments. For complex 2, the reduced ligand H 3 L 2 in a parallel fashion results in double relaxation processes and a 9-fold increase of the U eff . Interestingly, with the use of the dimerized ligand H 6 L 3 , we obtained complex 3, which is similar to complex 2, while due to the slight changes of the coordination environment both the single molecular magnetic property and toroidal magnetic moments almost disappeared.

Two new dysprosium complexes, [Dy(H 5 L)(NO 3 ) 2 (CH 3 OH) 2 ]·4CH 3 OH (1) and [Dy 2 (H 5 L) 2 (NO 3 ) 4 (H 2 O) 2 ]·10CH 3 OH (2), were isolated from the reaction of a novel 1,8-naphthalenediol-based ligand N,N'-((1,8-dihydroxynaphthalene-2,7-diyl)bis(methanylylidene))bis(2-hydroxybenzohydrazide), H 6 L with dysprosium(iii) nitrate upon crystallization at different temperatures. Because of a low-symmetrical coordination environment, both complexes display only field-induced single molecular magnetic (SMM) behavior. Interestingly, complex 2 containing two dysprosium ions shows field-induced multiple relaxation processes, whereas only one relaxation process is observed for complex 1. The remarkably different behavior observed in 2 is mainly ascribed to the weak intra- or intermolecular interactions between the two Dy III centres in this complex.

A unique Dy6 complex with a planar Dy3 + Dy3 structure was assembled by delicately modifying the axial ligands. Single-molecule magnet behavior and meanwhile a toroidal magnetic moment in the ground state have been observed.

An unprecedented octanuclear dysprosium(iii) cluster with the formula [Dy8L6(μ3-OH)4(μ2-CH3O)2(CH3OH)6(H2O)2]·6H2O·10CH3OH·2CH3CN () based on a nonlinearly tritopic aroylhydrazone ligand H3L has been isolated, realizing the successful linking of pairwise interesting triangular Dy3 SMMs. It is noteworthy that two enantiomers (Λ and Δ configurations) individually behaving as a coordination-induced chirality presented in the Dy3 helicate are connected in the meso Dy8 cluster. Remarkably, alternating-current magnetic susceptibility measurements revealed that the Dy8 cluster shows typical SMM behavior inherited from its Dy3 helical precursor. It is one of the rare polynuclear Lnn SMMs (n > 7) under zero dc field.

Two unique Dy6 complexes with fascinating Dy3 + Dy3 structures were assembled, showing single-molecule magnetic behavior with high energy barriers of 116 and 181 K for Dy6-NO3 and Dy6-SCN.

The initial employment of a triketone ligand in 4f coordination chemistry afforded a series of dinuclear complexes. Magnetic studies revealed that an antiferromagnetic interaction exists in a digadolinium(III) compound, while a dysprosium(III) constructed complex exhibits single-molecule magnet (SMM) behaviour at low temperatures with an energy barrier of 86.8 K.

Three pairs of homochiral mononuclear lanthanide complexes, with the general formula [LnH4LRRRRRR/SSSSSS(SCN)2](SCN)2·xCH3OH·yH2O(Ln = Dy (R/S-Dy1), Ho (R/S-Ho1) and Er (R/S-Er1)), have been obtained via self-assembly between chiral macrocyclic ligands and the respective thiocyanates, all of which show a saddle-type conformation with seven-coordinated metal ions. Magnetic measurements revealed that the Dy complex shows field-induced single-ion magnet behaviour, which is rarely reported in a seven-coordinated lanthanide-based SIM encapsulated in a macrocyclic ligand. The absolute configuration of all enantiomers was determined by single crystal X-ray crystallography and confirmed by electronic CD and VCD spectra.

Herein, we report a new approach to electromodulate the release of NO at physiological levels through polymeric materials from a stable nitrite electrolyte reservoir, with potential application in controlling biofilm formation and clotting on intravascular catheters. The NO flux can be turned 'on' and 'off' electrochemically, on demand.