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A new fluoride Ba4Ni3F14·H2O with a rare S = 1 staircase kagomé lattice shows a ferrimagnetic ground state.

We report the polarization reversal periodically controlled by the electric field in multiferroic MnWO4 with a pulsed field up to 52 T. The electric polarization can not be reversed by successive opposite electric fields in low magnetic fields (< 14 T) at 4.2 K, whereas the polarization reversal is directly achieved by two opposite electric fields under high magnetic fields (< 45 T). Interestingly, the polarization curve of rising and falling fields for H//u (magnetic easy axis) is irreversible when the magnetic field is closed to 52 T. In this case the rising and falling polarization curves can be individually reversed by the electric field, and thus requiring five cycles to recover to the initial condition by the order of the applied electric fields (+E, -E, -E, +E, +E). In addition, we find that ferroelectric phase IV can be tuned from parallel to antiparallel related to the ferroelectric phase AF2 by applying magnetic field approximated to the c axis.

A new compound BaNa2Co7Te3O18 features a unique spin network of (36; 34, 6)2, which is the first example of a distorted 2-uniform lattice (T13), showing unusual magnetic behaviors.

Search for transition-metal compounds with unique spin lattices is a great challenge. Herein, we report on a successful exploration of a new compound BaNa

Double perovskite oxides are one of the most promising bifunctional electrocatalysts for efficient oxygen evolution reaction (OER) and oxygen reduction reaction (ORR) due to their adjustable electronic structures via doping with different metal cations or engineering of defects. Herein, we report a systematic study on the tuning of the electronic structure of La2-xSrxNiMnO6 with 0 ≤ x ≤ 1.0 to promote the bifunctional OER/ORR activity. The bifunctional index (ΔE) is substantially reduced with increasing of Sr contents and achieves an optimal value of 0.85 V for La1.4Sr0.6NiMnO6, exceeding that of widely studied LaNiO3. Our study on electronic structures reveals that the enhancement of the ORR and OER activities strongly correlates with the appearance of Ni3+ oxidation states and the upshift of the O 2p-band center promoted by Sr doping. Furthermore, an increase of hole states, derived from Ni3+ states, reduces the energy barrier for the electron transfer from 0.44 to 0.12 eV and hence improves the intrinsic OER activities. The tuning of the electronic structure that leads to higher OER and ORR activities in La2-xSrxNiMnO6 can be extended to other materials for the design of active bifunctional electrocatalysts.

A mixed-valence manganese selenite, Mn

The exploration of two-leg spin-ladder materials is a great challenge to the chemical community since it is one of the most ideal models for the study of low-dimensional magnetism and high-Tc superconductivity. Herein, we report on a successful synthesis of a new Cu2+-based two-leg ladder compound constructed by CuO4Cl2 octahedra along the [101] direction. The magnetic results exhibit a broad peak at Tmax ∼ 265 K, and suggest that CdCu2(SeO3)2Cl2 has a spin singlet ground state. The fitting of the isolated two-leg spin-ladder model shows J⊥/kB = 429 K and J‖/kB = 21 K, leading to a large spin gap of ∼409 K.

A new pentanuclear {Co5} cluster motif is found to have a D3h oblate trigonal bipyramidal geometry, which is extended into a 3D triangle network, forming a unique capped breathing kagome lattice. Magnetic results confirmed a paramagnetism down to 2 K, accompanying the disappearance of two-thirds of the spin moment at low-temperature and the appearance of a 1/5 magnetization plateau.

The search for iron-sulfur-based coordination polymers (CPs) has become an attractive field in recent years. Here we demonstrate how it is possible to synthesize new iron-sulfur-based CPs by solvothermal reactions of [CpFe(CO)

Perovskite transition metal oxides are promising non-precious metal electrocatalysts for promoting the oxygen evolution reaction (OER) in many electrochemical energy conversion devices. This work reports a systematic study of the relation between the electronic structure and OER performance of perovskite La1−xSrxFeO3 (0 ≤ x ≤ 1). The partial substitution of La for Sr in LaFeO3 results in the oxidation of Fe3+ to Fe4+ and substantially enhances OER activity. A comprehensive X-ray spectroscopic study reveals a strong correlation of the enhanced OER activity with these Fe4+ states. The presence of Fe4+ leads to a stronger Fe–O bond due to stronger Fe 3d–O 2p orbital hybridization and shifts the energy position of the valence band (VB) to EF. Such an electronic modulation optimizes the surface adsorption energetics of *OH intermediates, contributing to faster OER kinetics. Furthermore, a new unoccupied state is created at ∼0.9 eV below the conduction band. This hole state reduces the energy barrier for electron transfer from 1.34 eV to 0.44 eV, thereby facilitating charge transfer at the interface. The Fe4+-induced electronic states responsible for higher OER activity have implications for the understanding of structure–activity relationships in other Fe-based electrocatalysts such as highly active Fe-doped NiOOH.

This work reports a systematical study on the relationship of electronic structure to oxygen evolution reaction (OER) activity of NixCo3-xO4 (x = 0-1) mixed oxides. The specific OER activity is substantially increased by 16 times from 0.02 mA cm-2 BET for pure Co3O4 to 0.32 mA cm-2 BET for x = 1 at an overpotential of 0.4 V and exhibits a strong correlation with the amount of Ni ions in the +3 oxidation state. X-ray spectroscopic study reveals that inclusion of Ni3+ ions upshifts the occupied valence band maximum (VBM) by 0.27 eV toward the Fermi level (EF), and creates a new hole (unoccupied) state located ∼1 eV above the EF. Such electronic features favor the adsorption of OH surface intermediates on NixCo3-xO4, resulting in enhanced OER. Furthermore, the emerging hole state effectively reduces the energy barrier for electron transfer from 1.19 to 0.39 eV, and thereby improves the kinetics for OER. The electronic structure features that lead to a higher OER in NixCo3-xO4 can be extended to other transition metal oxides for rational design of highly active catalysts.

The induction of leaf injuries, including leaf chlorosis and epinasty, by continuous light in tomato plants is one of the most interesting and mysterious phenomena regarding plant interactions with light, the mechanism of which has not yet been revealed. To gain further insights into this particular response of tomato plants, we cultivated tomato seedlings (Solanum lycopersicum cv. Momotaro) for 14 days under continuous light with different ratios of red and blue light and compared their performance to those grown under continuous or 14/10-h photoperiodic white light using novel methods to quantitatively evaluate the level of leaf chlorosis and epinasty. Continuous monochromatic blue light induced severe chlorosis but almost completely alleviated epinasty in tomato leaf. In contrast, continuous monochromatic red light caused a lower level of leaf chlorosis but very severe epinasty. The combination of red and blue light at different ratios significantly reduced both leaf chlorosis and epinasty under continuous light condition. Carbohydrate contents showed no correlation with leaf chlorosis, while glucose and fructose contents showed correlations with the petiole and leaflet curvatures. Histochemical staining with 3,3'-diaminobenzidine and nitro blue tetrazodium chloride also did not reveal any significant buildup of hydrogen peroxide and superoxide anion in monochromatic blue light treatment. Taken together, these results suggest that chlorosis and epinasty are two distinctive leaf injuries caused by continuous light that may follow very different mechanisms, and an overaccumulation of carbohydrates in the leaf may not be the main cause of continuous light-induced leaf chlorosis in tomato.

A new phase of cobalt(II) hydroxyl phosphate γ-Co2(PO4)(OH) has been successfully synthesized through a conventional hydrothermal method. This compound crystallizes in the trigonal system of space group P31m, showing a warping two-legs spin ladder chain structure arranged in an unusual triangular network, in which a new spin-lattice of (3, 6, 4, 6)(4, 62) is built by magnetic Co2+ ions. Magnetic measurements indicate that γ-Co2(PO4)(OH) may show a spin-glass behavior at low temperature.

A new pentanuclear {Co5} cluster motif is found to have a D3h oblate trigonal bipyramidal geometry, which is extended into a 3D triangle network, forming a unique capped breathing kagomé lattice. Magnetic results confirmed a paramagnetism down to 2 K, accompanying the disappearance of two-thirds of the spin moment at low-temperature and the appearance of a 1/5 magnetization plateau.

Understanding environmental factors is essential to maximizing the biomass production of plants. There have been many studies on the effects of the photosynthetic photon flux (PPF), photoperiod and air temperature as separate factors affecting plants, including under a closed transplant production system (CTPS). However, few studies have investigated the combined effects of these factors on plant growth. Germinated tomato and red pepper seedlings were transferred to three different photoperiods with five different photosynthetic photon fluxes (PPFs) at an air temperature of 25/20 &deg, C to investigate plant growth under a different daily light integral (DLI). Three different air temperatures, 23/20, 25/20, and 27/20 &deg, C (photo/dark periods), with five different PPFs were used to examine plant growth under different DIFs (difference between the day and night temperature). Increasing the DLI from 4.32 to 21.60 mol&middot, m&minus, 2&middot, d&minus, 1, either by increasing the photoperiod or PPF, improved the growth of seedlings in both cultivars. However, when comparing treatments that provided the same DLI, tomato seedlings had s significantly higher growth when grown under longer photoperiods and s lower PPF. Even in higher DLI conditions, reduced growth due to higher PPF indicated that excessive light energy was a limiting factor. At 23 and 25 &deg, C, tomato seedlings showed similar correlation curves between growth and PPF. However, at the higher temperature of 27 &deg, C, while the slope of the curve at low PPFs was similar to that of the curves at lower temperatures, the slope at high PPFs was flatter. On the other hand, red pepper seedlings displayed the same correlation curve between growth and PPF at all tested temperatures, and red pepper plants accumulated more dry weight even at higher temperatures. These results suggested that the combination effect was more useful to observe these overall tendencies, especially in reacting to a second factor. This will provide us with more information and a deeper understanding of plant characteristics and how they will behave under changing environments.

A novel compound Cu3(CH3COO)4(OH)2·5H2O was obtained by a hydrothermal method with a special synthesis process. The crystal structure is found to exhibit a unique one-dimensional diamond chain along the c-axis. Magnetic measurements confirmed that this compound exhibits unusual magnetic behaviors of a possible valence-bond condensation state at low temperature, where the two-thirds of all spins are condensed into spin singlets and one-third of the spins still remain in the paramagnetic state.

This work reports a fundamental study on the relationship of the electronic structure, catalytic activity and surface reconstruction process of Fe doped NiS2 (FexNi1-xS2) for the oxygen evolution reaction (OER). A combined photoemission and X-ray absorption spectroscopic study reveals that Fe doping introduces more occupied Fe 3d6 states at the top of the valence band and thereby induces a metallic phase. Meanwhile, Fe doping also significantly increases the OER activity and results in much better stability with the optimum found for Fe0.1Ni0.9S2. More importantly, we performed detailed characterization to track the evolution of the structure and composition of the catalysts after different cycles of OER testing. Our results further confirmed that the catalysts gradually transform into amorphous (oxy)hydroxides which are the actual active species for the OER. However, a fast phase transformation in NiS2 is accompanied by a decrease of OER activity, because of the formation of a thick insulating NiOOH layer limiting electron transfer. On the other hand, Fe doping retards the process of transformation, because of a shorter Fe-S bond length (2.259 Å) than Ni-S (2.400 Å), explaining the better electrochemical stability of Fe0.1Ni0.9S2. These results suggest that the formation of a thin surface layer of NiFe (oxy)hydroxide as an active OER catalyst and the remaining Fe0.1Ni0.9S2 as a conductive core for fast electron transfer is the base for the high OER activity of FexNi1-xS2. Our work provides important insight and design principle for metal chalcogenides as highly active OER catalysts.

The food-derived peptides hydrolyzed from native food protein matrix exhibited various bioactivities and multimeric structures, which make them the promising well-defined nanoplatforms candidates to co-deliver themselves with other bioactive compounds. In this study, zein-egg white derived peptides-chitosan (Z-EWDP-CS) ternary nanoparticles (NPs) were successfully fabricated by the spontaneous assembly to enhance the stability and bioactivity of curcumin (Cur). The novel ternary NPs exhibited a typical nano-spherical structure (138.63 nm, 40.50 mV), and adorable encapsulation efficiency (EE, 93.87%) for Cur. FTIR, XRD and DSC results verified that Cur changed from a crystalline state to an amorphous state, and was successfully entrapped in the cavity of Z-EWDP-CS NPs. Furthermore, the thermal stability, photochemical stability, salt stability, and antioxidant activity were considerably improved in the NPs after the addition of EWDP. Our results demonstrate that the food-derived peptides could be an ideal affinity agent for the co-delivery of themselves with hydrophobic nutraceuticals.

A new tellurate compound Na4CuTeO6 was synthesized by a conventional high-temperature solid state reaction. The titled compound crystallizes in the monoclinic system of a space group C2/c and exhibits a unique spin-chain structure built by planar CuO4 squares and TeO6 octahedra along the [101] direction. Magnetic measurements confirm that Na4CuTeO6 possesses an antiferromagnetic ordering at TN = ∼2.5 K. The intrachain and interchain interactions are estimated by a spin-chain model, showing a less pronounced 1D character in the system.

A new two-dimensional (2D) fluorophosphate compound Na3Cu5(PO4)4F·4H2O with a Cu5 cluster has been synthesized using a conventional hydrothermal method. The compound crystallizes in the orthorhombic crystal system with space group Pnma. The 2D layered structure is formed by cap-like {Cu5(PO4)4F} building units consisting of a Cu4O12F cluster plus a residual cap Cu2+ ion. Magnetic susceptibility exhibits a broad maximum at T2 = 19.2 K due to low-dimensional character followed by a long-range antiferromagnetic ordering at T1 = 11.5 K, which is further confirmed by the specific heat data. High-field magnetization measurement demonstrates a 2/5 quantum magnetization plateau above 40 T. The ESR data indicate the presence of magnetic anisotropy, in accordance with the 2D structure of the system.

A series of heterometallic 3d-4f hydroxyl sulfate-fluoride compound Ln2Cu(SO4)2(OH)3F·H2O (Ln = Gd, Ho, Yb) are synthesized by a conventional hydrothermal method. All of Ln2Cu(SO4)2(OH)3F·H2O family crystallize in the monoclinic system with a space group of P21/c, where the [CuO6]∞ and [Ln2O12F2]∞ chains are perpendicular to each other, featuring a three-dimensional framework. Magnetic measurements confirm that all of Ln2Cu(SO4)2(OH)3F·H2O family (Ln = Gd, Ho, Yb) exhibit a paramagnetic behavior down to 2 K, where the Weiss temperature θ of near zero, positive, and negative values is observed for Gd, Ho, and Yb-analogues, respectively, due to possibly different 3d-4f spin-orbital couplings.

A new fluorophosphate PbCuPO4F was obtained by a hydrothermal method, which is found to crystallize in the monoclinic system with a P21/c space group, exhibiting a tunnel structure built by distorted CuO4F square-pyramids and PO4 tetrahedra. Magnetic measurements show that this compound possesses a short-range magnetic order at ∼7.9 K without any antiferromagnetic transitions down to 2 K, indicating a singlet ground state. The fit by a modified spin-dimer model indicates intradimer interaction J/kB = 12.2 K and interdimer interaction J’/kB = 3.5 K in the system, while the critical field for the spin gap between the singlet ground state (S = 0) and the excited triplet states (S = 1) is observed at Hc = ∼4.7 T. Although PbCuPO4F and BaCuPO4F have a similar tunnels structure, their magnetic behaviors are remarkably different. This may be due to a slight change of interaction exchange in PbCuPO4F, leading to a coupled spin-dimer of Cu–O–P–O–Cu pathway in the 4-column tunnels. Also, solid-state UV–vis diffuse reflectance spectra show that PbCuPO4F has wide optical band gap of 3.42 eV.

Strawberry plants are at risk of exposure to short-term high daytime temperature (HTD) during flowering and exposure to short-term low temperature at night (LTN) during the coldest months of winter. The aim of this study was to identify the effects of short-term HTD or LTN on the different floral developments and fruit development, such as fruit malformation, flowering traits, stigma maturation, and pollen quality in ‘Seolhyang’ and ‘Maehyang’ strawberries. For the treatment of HTD, plants were treated at 35 °C, and for LTN treatment, plants were treated at 2 °C for consecutive days each. Days to flowering were shortened under HTD in both cultivars, while days to anther dehiscence were shortened under HTD. Stigma maturation was delayed by short-term extreme temperature stress in ‘Maehyang’. Short-term LTN before the flower petals appeared in the first and second flower clusters might cause high malformation rates in both cultivars. Pollen viability and the germination rate were decreased by HTD and LTN in both cultivars. There was a high correlation between the lower pollen germination rate and the higher percentage of malformed fruits under short-term LTN. These results suggest that even short-term exposure to low temperature in winter during cultivation should be controlled carefully considering developmental stages and cultivar-specific responses and that attention should be paid to the protection of strawberries.

Novel mixed-anionic-group compounds M 2 (SeO 3 )(Te 3 O 7 ) (M = Co 2+ , Ni 2+ ) are successfully synthesized by a conventional hydrothermal method. Two compounds are isostructural which crystallize in the orthorhombic system of a space group Pnma . The framework shows a (MO 6 ) ∞ chain structure along the b -axis, while SeO 3 groups are isolated and Te 3 O 7 groups form the (Te 3 O 7 ) ∞ chains running along the a -axis. This is the first time to realize transition-metal compounds coexisting with Se 4+ and Te 4+ anionic groups. Magnetic measurements show that Co 2 (SeO 3 )(Te 3 O 7 ) possesses an antiferromagnetic ordering at ∼11 K, while Ni 2 (SeO 3 )(Te 3 O 7 ) exhibits a similar antiferromagnetic ordering at ∼31 K. Also, the fitting of magnetic susceptibility using a spin-chain model gives the exchange coupling J /k B = −1.515 K for Co 2 (SeO 3 )(Te 3 O 7 ) and J /k B = −8.963 K for Ni 2 (SeO 3 )(Te 3 O 7 ), respectively.

Cs 2 NaMn 3 F 12 , one of manganese based fluorides A 2 A′Mn 3 F 12 (A = Rb, Cs; A′ = Li, Na, K), has been found to exhibit a typical kagome structure. Here, we report the first successful growth of large-sized single crystals of Cs 2 NaMn 3 F 12 by means of a hydrothermal method. Good quality of grown crystals is confirmed by the XRD and EDS techniques. Magnetic measurements suggest that Cs 2 NaMn 3 F 12 possesses an antiferromagnetic ordering at 2.5 K and a remarkably geometrical frustration effect in the system.

Three new molybdate-tellurites, K2M9(TeO3)4(MoO4)4(OH)4 (M = NiII and CoII) and (NH4)2Cu9II(TeO3)4(MoO4)4(OH)4, have been successfully synthesized by conventional hydrothermal method. Due to the influence of the Jahn-Teller effect, these compounds crystallize in different space groups of rhombohedral R3m, monoclinic P21/c and triclinic P1 for Ni-, Co-, and Cu-analogues, respectively. The topological arrangements of magnetic ions in these compounds show that deficient capped-kagome spin-lattices with kagome positions exhibit different 1/6 depletion. Magnetic and specific heat measurements confirm that K2Ni9(TeO3)4(MoO4)4(OH)4 exhibits a spin-glass behavior at low temperature, while (NH4)2Cu9(TeO3)4(MoO4)4(OH)4 possesses a long-range canted antiferromagnetic ordering with TN ∼ 10.8 K and further shows a 3/5 magnetization plateau in the magnetization curve at low temperature.

New tellurate compounds Na4MTeO6 (M = Co and Ni) were synthesized by a conventional high-temperature solid-state reaction. The title compounds crystallize in the monoclinic system of a space group P2/c and the triclinic system of a space group P, respectively. Both compounds exhibit a zigzag spin-chain structure, in which Na4CoTeO6 shows uniform chains built by Co2+ ions and Na4NiTeO6 shows alternating chains built by Ni2+ ions. Magnetic measurements confirm that Na4CoTeO6 and Na4NiTeO6 possess an antiferromagnetic ordering at TN = ∼3 K and ∼6.5 K, respectively, while a metamagnetic transition can be observed in the magnetization curve with an increasing field at 2 K.

Two new compounds Sr2Cu5(PO4)4X2·8H2O (X = Cl and Br) are synthesized by a conventional hydrothermal method. Sr2Cu5(PO4)4Cl2·8H2O crystallizes in the tetragonal system with a space group of P4212, while Sr2Cu5(PO4)4Br2·8H2O crystallizes in the space group P4/nmm, which are found to have a similar framework of layered structure, in which the crown-like {Cu5(PO4)4X2} building units connect to each other forming a 2D corrugated sheet with vacancies, while the Sr2+ cations are located along the vacancies. The spin lattice of two compounds built by Cu2+ ions shows a new type of corrugated square. Magnetic measurements confirmed that both Sr2Cu5(PO4)4X2·8H2O (X = Cl and Br) exhibit antiferromagnetic ordering at low temperatures. A fit of theoretical model shows exchange interaction J = −25.62 K for the Cl-analogue and J/kB = −26.47 K for the Br-analogue.

Two fluorophosphates, BaMPO4F (M = Cu, Co), have been synthesized by a conventional hydrothermal method, and they crystallize in the orthorhombic system with the space group P212121, exhibiting a tunnel structure built by distorted MO4F square-pyramids and PO4 tetrahedra. The magnetic behaviors of the two compounds are investigated by means of magnetic susceptibility, magnetization, and heat capacity measurements. The results indicate that BaCuPO4F exhibits a paramagnetic behavior down to 2 K, while BaCoPO4F undergoes long-range antiferromagnetic ordering at 11.3 K and short-range magnetic ordering at ∼22 K.

A new borophosphate Co3(BPO4)2(PO4)(OH)3 was synthesized by a conventional hydrothermal method. The titled compound crystallizes in the monoclinic system with space group Cc, which exhibits a typical spin-chain structure. In the structural framework, Co2+ ions form a zigzag chain via edge-sharing oxygen atoms, and further the zigzag Co-chains are separated by linear [B2P2O8]∞ chains. Magnetic measurements confirm that Co3(BPO4)2(PO4)(OH)3 possesses an antiferromagnetic ordering at TN = 12 K, while a 1/3 plateau is observed in the magnetization curve at 2 K. The possible spin arrangements for antiferromagnetic, ferrimagnetic, and ferromagnetic states are also suggested.

A new two-dimensional (2D) fluorophosphate compound Na

A new vanadate compound NaKV4O9·2H2O is successfully synthesized by a conventional hydrothermal method. This compound crystallizes in the monoclinic system with the space group C2/c, showing a typical 2D layered structure built from VO5 pyramids, in which the layers are separated by Na(+), K(+), and H2O. The topology structure of magnetic V(4+) ions shows a quite interesting 1/5-depleted square lattice, which is quite similar to that of a famous low-dimensional quantum spin system CaV4O9. A structural and magnetic comparison confirmed that the title compound may exhibit a more pronounced 2D character with a large spin gap.

Two vanadate compounds Ca{sub 5}M{sub 4}V{sub 6}O{sub 24} (M=Co, Ni) have been synthesized by a high-temperature solid-state reaction. The compounds are found to crystallize in the cubic system with a space group Ia-3d, which exhibit a typical garnet structural framework. Magnetic measurements show that Ca{sub 5}M{sub 4}V{sub 6}O{sub 24} (M=Co, Ni) exhibit similar magnetic behaviors, in which Ca{sub 5}Co{sub 4}V{sub 6}O{sub 24} possesses an antiferromagnetic ordering at T{sub N}=~6 K while Ca{sub 5}Ni{sub 4}V{sub 6}O{sub 24} shows an antiferromagnetic ordering at T{sub N}=~7 K. - Graphical abstract: Garnet vanadate compounds Ca{sub 5}M{sub 4}V{sub 6}O{sub 24} (M=Co, Ni) have been synthesized by a high-temperature solid-state reaction. Structural features and magnetic behaviors are also investigated. - Highlights: • New type of garnet vanadates Ca{sub 5}M{sub 4}V{sub 6}O{sub 24} (M=Co, Ni) are synthesized by a high-temperature solid-state reaction. • Structural features are confirmed by single crystal samples. • Magnetic behaviors are firstly investigated in the systems.

A series of 3d–4f hydroxysulfates Ln2Cu(SO4)2(OH)4 (Ln = Sm, Eu, Tb, or Dy) have been successfully obtained by the conventional hydrothermal method. These compounds crystallize in the monoclinic system in space group P21/c, showing a layered structure. The layers are built by the LnO9 polyhedra and CuO4 planar squares, which are separated by SO42– tetrahedra. The topological structure of Sm3+ ions shows a distorted honeycomb lattice, while Cu2+ ions are located at the center of a honeycomb framework forming a triangle lattice. Magnetic measurements reveal that the isostructural Ln2Cu(SO4)2(OH)4 exhibits different magnetic behaviors at low temperatures, which may be attributed to the different contribution of 3d–4f couplings.

A series of vanadate compounds Ba3M(V2O7)2 (M = Co, Mn, Mg, or Zn) are synthesized by a conventional high-temperature solid-state reaction. Four compounds are found to exhibit a similar structure, which all crystallize in the monoclinic system of space group P21/c. V5+ ions are tetrahedrally coordinated, forming corner-shared (V2O7)4– groups, while M2+ ions are octahedrally coordinated, forming edge-shared [M2O10] dimers. Isolated {M2V8O28}∞ clusters composed of [M2O10] dimer and (V2O7)4– groups form a pseudo-one-dimensional chain running along the a-axis. Magnetic measurements confirm that both Ba3Co(V2O7)2 and Ba3Mn(V2O7)2 show antiferromagnetic interaction exchanges in the systems, while luminescence measurements confirm that Ba3Mg(V2O7)2 and Ba3Zn(V2O7)2 have a broad emission band from 400 to 650 nm under 256 nm UV irradiation at room temperature.

Cu5(VO4)2(OH)4 (turanite) is a layered compound, exhibiting a copper(II) oxide layer in the [0 1 1] plane composed of edge-sharing CuO6 octahedra. Each Cu-O layer is further separated by VO4 tetrahedra. Closer scrutiny found that the copper(II) oxide layer in the compound represents a totally new geometrically-frustrated lattice, a 1/6 depleted triangular lattice. More specifically, the spin network in the [0 1 1] plane is formed by the alternate ranking of triangular and honeycomb strips. Magnetic measurements show that the Cu5(VO4)2(OH)4 behaves as a spin-1/2 ferrimagnet with a Tc = ∼4.5 K. It exhibits an unusual 1/5 magnetization plateau arising from the competition between antiferromagnetic and ferromagnetic interactions caused by the strong frustration. The possible spin-arrangements are also suggested.

Two fluorophosphates, BaMPO