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Protective autophagy is a promising target for antitumor drug exploration. A hydroxychloroquine (HCQ) platinum(IV) complex with autophagy suppressing potency was developed, which displayed potent antitumor activities with a TGI rate of 44.2% against 4T1 tumors in vivo and exhibited a rather lower toxicity than cisplatin. Notably, it exhibited satisfactory antimetastatic activities toward lung pulmonary metastasis models with an inhibition rate of 49.6% and was obviously more potent than CDDP, which has an inhibition rate of 21.6%. Mechanism detection revealed that it caused serious DNA damage and upregulated the expression of γ-H2AX and p53. More importantly, the incorporation of an autophagy inhibitor HCQ endowed the platinum(IV) complex with potent autophagy impairing properties by perturbing the lysosomal function in tumor cells, which promoted apoptosis synergistically with DNA injury. Then, the impaired autophagy further led to the suppression of hypoxia and inflammation in the tumor microenvironment by downregulating ERK1/2, HIF-1α, iNOS, caspase1 and COX-2. Adaptive immune response was improved by inhibiting the immune checkpoint PD-L1 and further increasing CD4+ and CD8+ T cells in tumors. Then, tumor metastasis was effectively inhibited by restraining angiogenesis through inhibiting VEGFA, MMP-9, and CD34. [ABSTRACT FROM AUTHOR]

The development of novel anticancer drugs with antiproliferative and antimetastatic activities is of great importance in the pharmaceutical field. Herein, a series of ligustrazine (LSZ) platinum(IV) complexes with chemotherapeutic and immunotherapeutic effects were designed, prepared and evaluated as antitumor agents for the first time. Complex 4 with potent antitumor activities both in vitro and in vivo was screened out as a candidate. Notably, it displays significantly more effective anti-metastatic activities than the platinum(II) drugs cisplatin and oxaliplatin. Mechanism detection discloses that it causes serious DNA damage and increases the expression of γ-H2AX and P53. Then, the apoptosis of tumor cells is promoted by activating the mitochondrial apoptotic pathway Bcl-2/Bax/caspase-3 and causing autophagy via modulating LC3-I/II and P62 expression. Furthermore, the immune therapeutic responses are significantly elevated by blocking HIF-1α, ERK 1/2 and COX-2 pathways to reduce PD-L1 expression, and further increasing CD3+ and CD8+ T cells to elevate T cell immunity in tumors. Tumor metastasis is blocked by the synergistic functions of DNA damage, hypoxia modulation and immune activation. [ABSTRACT FROM AUTHOR]

Inorganic lead halide perovskite quantum dots (CsPbX3 QDs (X = Cl, Br, or I)) have attracted more and more attention due to their high absorption coefficient, narrow emission band, high quantum efficiency, and tunable emission wavelength. However, CsPbX3 QDs are decomposed when exposed to bright light, heat, moisture, etc., which leads to severe luminous attenuation and limits their commercial application. In this paper, CsPbBr3@glass materials were successfully synthesized by a one-step self-crystallization method, including melting, quenching and heat treatment processes. The stability of CsPbBr3 QDs was improved by embedding CsPbBr3 QDs into zinc-borosilicate glass. Then, the CsPbBr3@glass was combined with polyurethane (PU) to form a flexible composite luminescent film CsPbBr3@glass@PU. This strategy enables the transformation of rigid perovskite quantum dot glass into flexible luminescent film materials and further improves the photoluminescence quantum yield (PLQY) from 50.5% to 70.2%. The flexible film has good tensile properties, and its length can be strained 5 times as long as the original length. Finally, a white LED was encapsulated by combining CsPbBr3@glass@PU film and red phosphor K2SiF6:Mn4+ with a blue LED chip. The good performance of the obtained CsPbBr3@glass@PU film indicates that it has potential application in flexible liquid crystal displays (LCDs) as a backlight source. [ABSTRACT FROM AUTHOR]

A cationic Ir(III) complex, Ir2, with a diphenylamino (DPA)-substituted 2-phenylbenzothiazole derivative as the cyclometalating ligand was designed and synthesized. Ir2 shows obvious aggregation-induced phosphorescent emission (AIPE) in H2O/CH3CN, compared with a non-DPA-substituted Ir1. The AIPE-active Ir2 demonstrates efficient detection of 2,4,6-trinitrophenol, providing a higher quenching constant (KSV = 2 644 330 M−1vs. 73 583 M−1 for Ir1) and a lower limit of detection (LOD = 2.23 nM vs. 50.17 nM for Ir1). High-resolution mass spectrometry analysis and density functional theory calculations demonstrate that photoinduced electron transfer may be responsible for the emission quenching. Immobilized in an ethyl cellulose film, Ir2 exhibits high oxygen sensitivity (K appSV = 0.0572 Torr−1vs. 0.0090 Torr−1 for Ir1) and excellent reversibility in 10 cycles. This work reveals that the DPA group plays an important role in tuning the AIPE properties and increasing the performances of the luminescent probes. [ABSTRACT FROM AUTHOR]

Through a mixed-ligand strategy, the structural change from a discrete dinuclear DyIII cluster to a one-dimensional polymeric chain was achieved, maintaining the two magnetic entities with the same {Dy(dppbO2)2(H2O)5} (dppbO2 = 1,4-butylenebis(diphenylphosphine oxide)) core structure. Since the hydrogen bonding between the equatorial coordinated water molecules and the guests/solvents/anions is distinct, the local geometry and the equatorial planarity of the first coordination sphere of the central DyIII ion become slightly different caused by the second coordination sphere. As a result, the dinuclear compound shows typical butterfly-shaped hysteresis loops, while it significantly opens at zero magnetic field up to 11 K for the 1D polymer, which is unprecedented in coordination polymers. Our experimental observations and theoretical analysis indicate that the hydrogen bonding leads to the fine-tuning of certain bond lengths and angles of the coordination environment, as well as the crystal field to a certain extent, revealing that the second coordination sphere affects the first coordination sphere by hydrogen bonding. [ABSTRACT FROM AUTHOR]

Efficient separation of neptunium and plutonium from spent nuclear fuel is essential for advanced nuclear fuel cycles. At present, the development of effective actinide separation ligands has become a top priority. As common adsorbents for extracting uranium from seawater, amidoxime-based adsorbents may also be able to separate actinides from high-level liquid waste (HLLW). In this work, the complexation of Np(IV , V , VI) and Pu(IV) and alkyl chains (R = C13H26) modified with amidoximate (AO−) and carboxyl (Ac−) functional groups was systematically studied by quantum chemical calculations. For all the studied complexing species, the RAc− and RAO− ligands act as monodentate or bidentate ligands. Complexes with AO− groups show higher covalency of the metal–ligand bonding than the analogues with Ac− groups, in line with the binding energy analysis. Bonding analysis verifies that these amidoxime/carboxyl-based adsorbents possess higher coordination affinity toward Pu(IV) than toward Np(IV), and the Np(VI) complexes have stronger covalent interactions than Np(V). According to thermodynamic analysis, these adsorbents have the ability to separate Np(IV , V , VI) and Pu(IV), and also exhibit potential performance for partitioning Pu(IV) from Np(IV) under acidic conditions. This work can help to deeply understand the interaction between transuranium elements and amidoxime-based adsorbents, and provide a theoretical basis for the separation of actinides with amidoxime-based adsorbents. [ABSTRACT FROM AUTHOR]

A series of Gd2−xMoO6:xEu3+ (x = 0.18–0.38) nanophosphors were synthesized by the solvothermal method. The properties of these nanophosphors were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), fluorescence spectroscopy and diffuse reflectance spectroscopy. Gd2−xMoO6:xEu3+ nanophosphors have a strong excitation band in the NUV region and emit red light with high color purity by efficient energy transfer from the MoO66− group to Eu3+ ions. Red LEDs and WLEDs were fabricated using a 370 nm chip and Gd2−xMoO6:0.26Eu3+ nanophosphors, which showed good electroluminescence performance. At a driving current of 20 mA, WLEDs displayed CIE coordinates of (0.3297, 0.3869), a correlated color temperature (CCT) of 5604 K and a high color rendering index (Ra) of 91.6. This work demonstrates that Gd2−xMoO6:xEu3+ phosphors are promising red phosphors excited by a NUV chip for WLEDs. [ABSTRACT FROM AUTHOR]

The design of novel platinum(IV) complexes with mitochondria injury competence, besides the DNA damage mechanism, is a promising way to develop new platinum drugs. Herein, dihydro-2-quinolone (DHQLO) as a mitocan was incorporated into the platinum(IV) system for the first time to prepare a new series of DHQLO platinum(IV) compounds. Complex 1b could effectively inhibit the proliferation of tumor cells in vitro and in vivo. It accumulated at higher levels in both whole cells and DNA, and easily underwent intercellular reduction to release platinum(II) and DHQLO moieties. The released platinum(II) complex caused serious DNA damage by covalent conjunction with the DNA duplex, and remarkably increased the expression of the γ-H2AX protein. Moreover, 1b also caused serious mitochondria injury to induce mitochondrial membrane depolarization and increase ROS generation. Such actions upon DNA and mitochondria activate the p53 apoptotic pathway synergetically in tumor cells by upregulating the protein p53 and apoptotic proteins caspase9 and caspase3, which efficiently promoted the apoptotic death of tumor cells. Compound 1b with such synergic mechanism exhibited great potential in reversing cisplatin resistance and improving antitumor efficacies. [ABSTRACT FROM AUTHOR]

By employing mixed ligands, a new trinuclear dysprosium complex [Dy3(dbm)3(L)4](ClO4)2·CH2Cl2·2MeOH (1, Hdbm = dibenzoylmethane; HL = 2-methoxy-6-((quinolin-8-ylimino)methyl)phenol) was synthesized by a one-pot reaction. According to structural characterization, all the 8-coordinated Dy(III) sites are well arranged with slightly distorted square antiprism (D4d) geometries. Magnetic measurements reveal that 1 exhibits typical single-molecule magnetic behavior at zero magnetic field and shows rarely open hysteresis loops up to 3 K among open-ring {Dy3} SMMs, where the relaxation time remains very stable under the protection from the Dy–Dy magnetic coupling in the open-ring arrangement of Ising spins. [ABSTRACT FROM AUTHOR]

Cycloxygenases (COXs) and matrix metalloproteinases (MMPs) in the tumor microenvironment (TME) are tightly related to the progression of cancers. Here, naproxen as a potent inhibitor of both COX and MMP was combined with platinum(IV) to construct hybrids as antitumor agents. Compound 2 with comparable or even superior activities to that of cisplatin, oxaliplatin, and carboplatin, great potential for reversing drug resistance, and superior tumor targeting properties was screened out as a lead compound. Moreover, compound 2 possessed potent tumor growth inhibition capability in vivo, which was comparable to that of oxaliplatin, and displayed rather lower side effects than the platinum(II) reference drugs. The naproxen platinum(IV) complex could easily undergo reduction and liberate the platinum(II) complex and naproxen as well as exert a multifunctional antitumor mechanism: (i) the liberated platinum(II) fragment would cause serious DNA injury; (ii) naproxen would inhibit COX-2 and decrease tumor-associated inflammation; and (iii) the naproxen platinum(IV) complex exhibited remarkable MMP-9 inhibition in tumor tissues. These antitumor functions can help reduce the growth and metastasis of malignancy. [ABSTRACT FROM AUTHOR]

Two new inorganic metal borate derivatives, Sr5TeO2(BO3)4 and NaSr5(BO3)(SiO4)2, have been obtained through a high temperature solid reaction method. Sr5TeO2(BO3)4 crystallizes in a tetragonal space group of P4/mnc featuring a three-dimensional (3D) structure composed of a porous 3D strontium framework stabilized by the unique zero-dimensional (0D) [TeO2(BO3)4]10− anions. NaSr5(BO3)(SiO4)2 crystallizes in a monoclinic space group of P21/c with a 3D structure consisting of a splendid strontium 3D framework strengthened by isolated BO3 and SiO4 groups. The sodium cations located in the empty space of the structure. Thermal stability analyses, optical property measurements and theoretical studies of the compounds were performed. Refractive index calculations revealed that the birefringence of Sr5TeO2(BO3)4 and NaSr5(BO3)(SiO4)2 is 0.048 and 0.029, respectively, at 1064 nm. [ABSTRACT FROM AUTHOR]

Defective Fe3+ self-doped spinel ZnFe2O4 with abundant oxygen vacancies, (Zn1−xFex)Fe2O4−y, was successfully synthesized via a simple spin-coating method and subsequent hydrogen reduction treatment. It displays a photocurrent density of 0.22 mA cm−2 at 1.23 (V vs. RHE), which is 11 times higher than that of pure ZnFe2O4. The largely enhanced photoelectrochemical (PEC) performance can be mainly ascribed to the synergism of the numerous oxygen vacancies and self-doped Fe3+, which has never been discussed carefully. Self-doped Fe3+ can be beneficial for increasing the charge carrier densities, while oxygen vacancies can improve the charge mobility and prompt the charge transfer process at the electrolyte interface, leading to improved electric conductivities and faster water oxidation kinetics. Furthermore, the effects of the concentrations of Fe3+ self-doping as well as oxygen vacancies on the PEC activities of ZnFe2O4 were also investigated. This work develops a novel and effective strategy to solve the critical problems existing in ZnFe2O4 for PEC applications and sheds light on the rational design of photoanode materials for efficient PEC water splitting. [ABSTRACT FROM AUTHOR]

A 3d–4f heterometallic metallacrown with formula of [EuCu5(quinha)5(sal)2(py)5]CF3SO3·py·3H2O (1) (H2quinha = quinaldichydroxamic acid; Hsal = salicylaldehyde) has been synthesized. This complex shows field-induced slow magnetic relaxation via a Raman-like process, where studies of the isostructural {LuCu5} (2) and {YCu5} (3) complexes show that the slow dynamics mainly arise from the {Cu5} S = 1/2 ground state rather than the EuIII ion. However, the EuIII ion enhances the relaxation rates of the {Cu5} unit which likely arises from second-order effects in the formally diamagnetic 7F0 ground state of EuIII. [ABSTRACT FROM AUTHOR]

Three novel 3D lanthanide–organic frameworks, namely [Ln2L(1,3-bdc)3]·5H2O (Ln: Eu, Sm and Dy), with a 412·63 topology based on a zwitterionic ligand, 4-bis(4-carboxylatopyridinium-1-methylene)benzene dichloride (H2LCl2), and 1,3-benzene dicarboxylic acid (1,3-H2bdc) have been synthesized hydrothermally. Notably, the Ln-MOFs are extremely stable in an aqueous system and are capable of resisting acids or bases over a wide pH range from 3 to 11. Meanwhile, an Eu-MOF is further proven to be a promising dual sensor in an aqueous system toward Cr2O72− and Fe3+. [ABSTRACT FROM AUTHOR]

A cyano-bridged Cu(i) organic framework based on [Cu6(CN)6]n was synthesized, in which cyano anions were generated in situ from the C–C bond cleavage of acetonitrile. The as-synthesized compound displays orange-red luminescence and is further proven to be a promising Fe3+ luminescent sensor with high selectivity and sensitivity. [ABSTRACT FROM AUTHOR]

A 4-amino-1,2,4-triazole (NH2-trz) based linear trinuclear Fe(ii) complex of [Fe3(NH2-trz)6(SCN)4(H2O)2](SCN)2·H2O (1) has been hydrothermally synthesized by the reaction of a NH2-trz ligand with FeSO4. A single crystal of complex 1 is able to extrude one lattice water and one coordinated water, leading to another single crystal of complex 1a with a formula [Fe3(NH2-trz)6(SCN)5(H2O)](SCN) by heating. Complex 1a can be reversed to 1 upon the reabsorption of water. Single-crystal X-ray diffraction analysis reveals that these two complexes consist of a linear trinuclear core where a central Fe1 ion is coordinated to six nitrogen atoms from six bridged NH2-trz ligands and one of the terminal Fe2 ions is coordinated to five nitrogen atoms and one oxygen atom. The terminal Fe3 ion in 1 coordinates to five nitrogen atoms and one oxygen atom; however, the terminal Fe3 ion in 1a coordinates to six nitrogen atoms. Magnetic susceptibility measurements demonstrate that they exhibited gradual spin crossover (SCO) for the central Fe(ii) ion; however, different spin transition temperatures were displayed for complexes 1 and 1a (T1/2 = 202 K for 1 and 160 K for 1a). These different spin transition temperatures arise from the different intermolecular hydrogen bonding interactions in the two complexes. [ABSTRACT FROM AUTHOR]

The rational design of non-noble materials as low-cost, highly efficient, and durable catalysts to improve the oxygen reduction reaction is extremely urgent and challenging. The oxygen reduction reaction is a kinetically sluggish process that greatly affects the energy conversion efficiency. In this paper, novel hierarchical heteroatoms-co-doped Fe2M/graphene (M = P, N) nanocomposites were developed by a facile strategy, including hydrothermal and subsequent calcination methods. The thermal treatment of an ionic liquid and thiourea not only supplied heteroatom sources but also promoted the formation of iron phosphide and iron nitride and enhanced their catalytic performances. The electrochemical results indicated that the as-obtained hybrid catalysts manifested enhanced electrocatalytic activity toward the oxygen reduction reaction owing to the strong synergistic effects. The high content of heteroatoms distributed on the surface and interface of the hybrids and the density functional theory calculations suggested that Fe–N–C, Fe–P–C, and Fe–S–C multiple active surface sites were formed at the hybrids interfaces. Moreover, these results demonstrated that heteroatom-doped catalysts could effectively form a charge-transfer channel and thus modify the charge distribution in the hybrids interfaces. The as-prepared heteroatoms-doped Fe2M/graphene hybrids would be developed into highly efficient catalysts as ideal alternatives for noble metal catalysts in practical applications. [ABSTRACT FROM AUTHOR]

A wheel-shaped Dy(iii) single-molecule magnet (SMM), supported by polyoxotungstates, Cs15K8Na12[K⊂{(AsW9O33)Dy(H2O)2}6]·71H2O (1), is described here. The polyanion of 1 possesses an idealized S6 symmetry. The effective energy barrier (68 K) obtained from magnetic studies is consistent with the deconvolution of the luminescence spectra of 1. [ABSTRACT FROM AUTHOR]

Herein, the coordination chemistry of a series of Cu(ii) complexes of various aminoalcohol and benzoate ligands was explored. The pH-dependent reactions of copper(ii) salts with propanolamine (Hpa), N-methyl diethanolamine (H2mdea), triethanolamine (H3tea), and nbutyl-diethanolamine (H2budea) were carried out in the presence of various benzoates (benzoic acid, 2-hydroxy benzoic acid, 4-hydroxy benzoic acid, 3-methoxy benzoic acid, and 4-methoxy benzoic acid). The resulting complexes [Cu2(pa)2(benzoate)2] (1), [Cu2(pa)2(3-methoxybenzoate)2] (2), [Cu2(pa)2(4-methoxybenzoate)2] (3), [Cu2(H2tea)2(benzoate)2]·2H2O (4), [Cu2(H2tea)2(2-hydroxybenzoate)2]·2H2O (5), [Cu2(H3tea)2(4-hydroxybenzoate)2][Cu(Htea)2]·2H2O (6), [Cu(H2mdea)2][benzoate]2 (7), [Cu(H2mdea)2][4-methoxybenzoate]2 (8), [Cu(H2bdea)2][2-hydroxybenzoate]2 (9), [Cu2(benzoate)4(benzoic acid)2] (10), [Cu2(4-methoxybenzoate)4(CH3CN)2]·4CH3CN (11) and [Cu3(H2tea)2(benzoate)2(NO3)2] (12) were formed as mono-, di- or trinuclear entities depending upon the pH conditions of the reaction. The complexes were characterized employing spectral, magnetic, single-crystal X-ray and DFT/TDDFT studies. 7 and 8 exhibited emission peaks at 510 and 460 nm, respectively, in the solid-state photoluminescence (PL) spectra. The temperature variable magnetic properties of 1–12 revealed the presence of antiferromagnetic (in 1–3 and 7–11) or ferromagnetic interactions (in 4–6 and 12) with Curie constants C = 0.24 (7), 0.28 (8) or 0.35 cm3 K mol−1 (9) and Weiss constants ϑ = −0.34 (7), −0.32 (8) or −0.40 (9) K for the mononuclear complexes. The dinuclear complexes demonstrated J values of −89.2(2) (1), −71.1(3) (2), −59.6(1) (3), 98(1) (4), 79.1(2) (5), −85.4(2) (10) and −89.5(2) (11) cm−1. Strong ferromagnetic interactions were observed in the case of 6 (J = 172(3) cm−1 and zJ′ = 2.3(2) cm−1), which were comparable with those of 12 (J12 = 197(2) cm−1, J13 = −9.3(3) cm−1). A correlation exists between the Cu–O–Cu angle and magnetic coupling in di- and trinuclear Cu(ii) complexes. Moreover, 4–6 were active catalysts for the oxidation of 3,5-DTBC to 3,5-DTBQ and showed catecholase activity in the order 4 ＞ 5 ＞ 6 (Kcat = 943 (4), 698 (5) and 553 h−1 (6)). This order can be rationalized in terms of the electron density on the ligand, which neutralizes the effective positive charge on Cu(ii), thus forming the less or more stable intermediate. The order of catecholase activity and the electronic spectral properties of 4–6 were also investigated by DFT and TDDFT studies, respectively. [ABSTRACT FROM AUTHOR]

Two dysprosium aggregates, formulated as [Dy2(μ-OH)2(H2bpte)2Cl2(MeOH)2]Cl2 (1), and [Dy8(μ-OH)8(bpte)8]·24H2O (2) (H2bpte = 1,2-bis(3-(pyridin-2-yl)-1H-1,2,4-triazol-5-yl)ethane), were obtained using solvothermal reactions. Upon changing the metal salt and synthetic reaction conditions, an eight-member {Dy8} (2) ring was isolated. Complex 1 is centrosymmetric in which two {Dy2} clusters are connecting to each other through the hydrogen bonding. Complex 2 forms an eight-member DyIII ring with an inner diameter of 4.5 Å and is the first reported {Dy8(μ-OH)8} core in lanthanide-hydroxo clusters. The H2bpte ligand displays trans,trans- and cis,cis-coordination modes in 1 and 2, respectively. Alternating current (ac) magnetic measurements of both complexes were carried out. In 1, the out-of-phase susceptibilities (χ′′M) below 9 K confirm the slow relaxation of magnetization, which is a typical characteristic of single-molecule magnets (SMMs). [ABSTRACT FROM AUTHOR]

Four isostructural 3D lanthanide(iii) metal–organic frameworks with the general formula (H6edte)0.5[LnIII(ox)2(H2O)] (Ln = Gd (1), Tb (2), Dy (3) and Ho (4); H4edte = N,N,N′,N′-tetrakis(2-hydroxyethyl)ethylenediamine) and ox = oxalate have been synthesized from oxalate. These compounds were characterized using single-crystal X-ray diffraction, FTIR and TGA/DTG. The magnetic investigation has been performed for 1–4 and the results reveal that a Gd(iii) containing MOF has the highest magnetic density and exhibits a larger cryogenic magnetocaloric effect (ΔSm = 35.9 J kg−1 K−1 for ΔH = 9 T at 2.0 K) with a high Debye temperature (ϑD = 342(3) and rD = 35). For the Dy derivative, an ac-out-of-phase signal was found, and further measurements under an applied field of 1000 Oe showed frequency-dependent out-of-phase magnetic susceptibility. Solid-state luminescence indicates that Tb and Dy-containing complexes are photoluminescent materials. [ABSTRACT FROM AUTHOR]

Eight isostructural lanthanide coordination polymers [Ln(bptc)(phen)(H2O)]n (Ln = Dy for 1, Eu for 2, Tb for 3, Gd for 4, Sm for 5, Nd for 6, Yb for 7, Pr for 8) were successfully prepared based on bridging asymmetric polycarboxylate ligand biphenyl-3,2′,5′-tricarboxylic acid (H3bptc) and chelating 1,10-phenanthroline (phen) coligand. Single crystal X-ray analysis reveals that complexes 1–8 have a (3,6)-connected CdI2-type coordination network consisting of paddle-wheel dimers [Ln2(CO2)4]. The magnetic and fluorescent properties of 1–8 have been investigated. Significantly, the Dy(iii) complex 1 behaves with slow relaxation of the magnetization, where the frequency-dependent out-of-phase signals are noticed. [ABSTRACT FROM AUTHOR]

The perturbation to the ligand field around the lanthanide ion may significantly contribute to the magnetic dynamics of single molecule magnets. This can be demonstrated by two typical Dy4 cluster-based single molecular magnets (SMMs), [Dy4X2(μ3-OH)2(μ-OH)2(2,2-bpt)4(H2O)4]X2·2H2O·4EtOH (X = Cl and Br for 1 and 2, respectively), which were constructed by using 3,5-bis(pyridin-2-yl)-1,2,4-triazole (2,2-bptH) as the polynuclear-chelating ligand. Alternating-current (ac) magnetic susceptibility measurements show that the energy barriers in complexes 1 and 2 were immensely enhanced by comparing with our previous work due to the optimization of the ligand field around DyIII ions. Remarkably, their high thermal active barriers at 190 K (1) and 197 K (2) under a zero applied external dc magnetic field are also among the highest within the reported tetranuclear lanthanide-based SMMs. [ABSTRACT FROM AUTHOR]

Four single-phase isostructural mononuclear complexes (HNEt3)[DyxYb1−x(bpyda)2]·3H2O (x = 1 (1), 0 (2), 0.367 (3), 0.135 (4), bpyda = 2,2′-bipyridine-6,6′-dicarboxylate) show characteristics of controllable slow relaxation and photoluminescence. The molecular hybrids 3 and 4 exhibit the Orbach process for the DyIII component and a mixture of direct and Raman processes for the YbIII component. The presence of paramagnetic YbIII enhances the relaxation time of the DyIII component, originating from the suppression of the direct process/QTM. The correlation between photoluminescence, static susceptibilities and dynamic magnetic relaxation in the hybrid species was also analysed by comparing the energy gap between the ground and first excited states to the energy barrier. [ABSTRACT FROM AUTHOR]

Three novel heteropolyanions [PMo12Sb2O40][Cu(enMe)2]·4H2O (1), [PMo12Sb2O40][Ni(enMe)2]·4H2O (2) and [PMo12Sb2O40][Cu(en)2]·H3O·H2O (3) (enMe = 1,2-diaminopropane, en = ethylene diamine) have been synthesized and characterized by IR spectroscopy, X-ray photoelectron spectroscopy (XPS), thermogravimetric analyses and elemental analyses. Single-crystal X-ray diffraction analyses reveal that these three compounds represent the first examples of compounds based on the novel polyoxoanion {PMo12Sb2O40} and different transition metal coordination complexes. 1and 2are isostructural and both exhibit novel 1-D structures. In contrast to 1and 2, 3exhibits a substantially distinct novel 1-D structure. In addition, 3is the first example of an extended structure constructed from polyoxoanions and Cu+transition metal coordination complexes. [ABSTRACT FROM AUTHOR]