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Two new heterometallic uranyl-organic frameworks (UOFs), [Cd(phen)2(H2O)2][(UO2)2(BDC)3]·2H2O (1) and [Ni(phen)3][(UO2)2(BDC)3]·2H2O (2), were obtained under hydrothermal conditions. Both crystal structures were characterized by single-crystal X-ray diffraction analyses and the results indicate that both complexes feature a similar 2D honeycomb framework that is connected by rigid benzenedicarboxylate (BDC) ligands and uranyl units. BDC works as a linker to bridge neighboring UO22+ units, where UO22+ is tris-chelated. Different guest molecules guided the stacking of 2D layers and lead into their 3D supramolecular crystal structures with different space groups. As a result, 1 crystallized in a polar space group Cc, whereas 2 belongs to a chiral space group P6122. Thermogravimetric measurements were performed to study their thermal stability. UV-visible diffuse reflectance spectroscopy measurements indicate an experimental optical bandgap of 3.87 eV and 3.63 eV, respectively, for 1 and 2. Luminescent studies of both samples show strong green light emissions.

Nano α-glycine crystals, γ-glycine crystals, and amorphous solid dispersion (ASD) of glycine were prepared through solvent-free ball milling of commercial α-glycine. The solid-state polymorph conversion of glycine from α to γ was completely realized by ball milling with 0.2 wt.% NaCl for 1 h or by ball milling with 0.02 wt.% NaCl for 1 h with subsequent storage for one week. The ASD of glycine was prepared by ball milling α-glycine with an equal amount of CaCl2 for 1 h. We studied the effect of inorganic salt types and their concentrations on the extent of polymorph conversion and amorphization of glycine in our experiments. This solvent-free ball milling method could be used for the synthesis of polymorphs and amorphous phase of drugs and other organic materials.

As a widely used industrial additive of plastic products, phthalate ester (PAE) plasticizers can easily migrate into food, threatening human health. In this work, we proposed a rapid, precise, and reliable method to detect PAE plasticizers in edible oils by using surface-enhanced Raman spectroscopy (SERS) technology. A two-dimensional (2D) silver plate synergizing with a nanosilver sol was prepared as a substrate for SERS to detect potassium hydrogen phthalate (PHP), a hydrolysate of a PAE plasticizer. Detection conditions, such as pH values, drying times, and hydrolysate interference, were optimized. The working curve was well fitted with a linear parameter R

The new, quaternary diamond-like semiconductor (DLS) Cu4MnGe2S7 was prepared at high-temperature from a stoichiometric reaction of the elements under vacuum. Single crystal X-ray diffraction data were used to solve and refine the structure in the polar space group Cc. Cu4MnGe2S7 features [Ge2S7]6- units and adopts the Cu5Si2S7 structure type that can be considered a derivative of the hexagonal diamond structure. The DLS Cu2MnGeS4 with the wurtz-stannite structure was similarly prepared at a lower temperature. The achievement of relatively phase-pure samples, confirmed by X-ray powder diffraction data, was nontrival as differential thermal analysis shows an incongruent melting behaviour for both compounds at relatively high temperature. The dark red Cu2MnGeS4 and Cu4MnGe2S7 compounds exhibit direct optical bandgaps of 2.21 and 1.98 eV, respectively. The infrared (IR) spectra indicate potentially wide windows of optical transparency up to 25 μm for both materials. Using the Kurtz-Perry powder method, the second-order nonlinear optical susceptibility, χ(2), values for Cu2MnGeS4 and Cu4MnGe2S7 were estimated to be 16.9 ± 2.0 pm V-1 and 2.33 ± 0.86 pm V-1, respectively, by comparing with an optical-quality standard reference material, AgGaSe2 (AGSe). Cu2MnGeS4 was found to be phase matchable at λ = 3100 nm, whereas Cu4MnGe2S7 was determined to be non-phase matchable at λ = 1600 nm. The weak SHG response of Cu4MnGe2S7 precluded phase-matching studies at longer wavelengths. The laser-induced damage threshold (LIDT) for Cu2MnGeS4 was estimated to be ∼0.1 GW cm-2 at λ = 1064 nm (pulse width: τ = 30 ps), while the LIDT for Cu4MnGe2S7 could not be ascertained due to its weak response. The significant variance in NLO properties can be reasoned using the results from electronic structure calculations.

The novel diamond-like Li4CdSn2S7 possesses many outstanding attributes that enable it to be a new, well-rounded front-runner among infrared (IR) nonlinear-optical materials, especially for high-in...

Exploring new nonlinear optical (NLO) materials with high laser-induced damage threshold (LIDT) in the infrared (IR) region is vital for the development of technologies relying on tunable laser sys...

The new, quaternary diamond-like semiconductor (DLS) Cu

The present work concerns calcium pyroselenites CaSe2O5 with two independent crystal structures, their difference physical properties and phase transformations. α-CaSe2O5 in orthorhombic form shows 2D calcium oxide anionic layers whereas new compound β-CaSe2O5 crystallizes in monoclinic space group C2/c. It's a new structure type with 1D calcium oxide thick chains which are further connected by Se2O5 dimers. Rietveld refinement indicates that the weight fraction for α/β-CaSe2O5 mixture phase was found to be 84.5% and 15.5% for α- and β-CaSe2O5, respectively. Optical diffuse reflectance spectrum coupled with Kubelka–Munk fit gives a result that α-CaSe2O5 adopts direct optical transition model while β-CaSe2O5 is an indirect semiconductor. The experimental result matches well with the prediction of theory calculation. The optical bandgap values were fitted to be 4.74 and 4.12 eV for α- and β-CaSe2O5, respectively. Thermal analysis coupled with variable temperature powder XRD indicates the phase transformation between these two phases.

In this study, two quaternary diamond-like semiconductors (DLSs) in the Cu-Zn-Ge-Se system, the known Cu2ZnGeSe4 (also referred to as CZGSe) and the new Cu4ZnGe2Se7, are compared in terms of their crystal structures, electronic structures and physicochemical properties. Both compounds were prepared by high-temperature, solid-state synthesis at 800 °C. Single crystal X-ray diffraction was used to determine the structure of Cu4ZnGe2Se7. The structures of both Cu2ZnGeSe4 and Cu4ZnGe2Se7 can be considered as derivatives of cubic diamond. Cu4ZnGe2Se7, with a reduced symmetry due to the cation ordering pattern, adopts the Cu4NiSi2S7 structure type, with space group C2. The corner-sharing tetrahedra in Cu4ZnGe2Se7 are slightly distorted because the charge for some of the S2- anions is not compensated by the first-nearest-neighbor cations. Rietveld refinements using synchrotron X-ray powder diffraction data were used to assess the phase purity of the samples and confirm the bulk structural behavior. Diffuse reflectance UV/Vis/NIR spectroscopy shows that Cu2ZnGeSe4 and Cu4ZnGe2Se7 have direct optical bandgaps of 1.38 and 0.91 eV, respectively. Electronic structure calculations implementing density functional theory confirm the direct bandgap for Cu4ZnGe2Se7, with a calculated value of 0.62 eV. Both compounds are air stable, thermally stable up to relatively high temperatures, undergo phase transitions and have wide windows of optical clarity. The Kurtz-Perry powder technique was used to determine the second harmonic generation (SHG) responses using a commercial AgGaSe2 standard. While Cu4ZnGe2Se7 displays a weak SHG response, Cu2ZnGeSe4 exhibits a response that is greater than several benchmark materials, with a large SHG coefficient, χ ( 2 ) , of 43 ± 6 pm/V at λ = 2900 nm.

Two new alkali boroselenites RbSe3B2O9(OH) and CsSe3B2O9(OH) have been synthesized by traditional solid-state reactions. Single-crystal X-ray diffraction study indicated that they are isostructural and adopt a new type of structure, which crystallizes in the noncentrosymmetric space group P212121. Optical diffuse reflectance spectrum studies emphasized that both are indirect optical transitions with values of 3.79 and 4.17 eV for RbSe3B2O9(OH) and CsSe3B2O9(OH), respectively. Optical analysis revealed a broad transparency window in the 0.3-8.5 μm region for both compounds. In addition, RbSe3B2O9(OH) featured a relatively weak second-harmonic-generation response, and for CsSe3B2O9(OH), the response is 0.8-times that of KH2PO4. Theoretical calculations of band structure, density of state, and linear and nonlinear optical properties were also performed to get insight into the relationships between electronic structures and their optical properties.

Herein, unprecedented NLO-brominated tin hypophosphites, namely [Sn2(H2PO2)3]Br, were discovered via a facile surfactant-induced method, which displayed a moderate powder SHG intensity (3.0 × KDP) in type – I phase matching behavior. This complex has high chemical and thermal stability at room temperature. DFT calculations and SHG coefficient analyses revealed that the alignment of the SHG-active-units SnO3 trigonal pyramids and Br− anions in its structure mainly contribute to the macroscopical SHG behaviors.

Two new biaxial, diamond-like semiconductors, Li2CdGeSe4 and Li2CdSnSe4, were prepared via high-temperature, solid-state synthesis. Single crystal X-ray diffraction and X-ray powder diffraction coupled with Rietveld refinement were used to refine the crystal structures and assess the phase purity, respectively. Both compounds adopt the lithium cobalt(II) silicate structure type. Strong second-order nonlinear optical (NLO) susceptibility, phase matchability, relatively high thermal stability, and excellent transparency deem both materials potential infrared (IR) NLO candidates. Li2CdGeSe4 and Li2CdSnSe4 display optical bandgaps of approximately 2.5 and 2.2 eV, respectively. Li2CdSnSe4 exhibits a strong, red-light emission under 1064 nm excitation, allowing the compound to release energy that accumulates by two-photon absorption under Nd:YAG laser radiation. Therefore, Li2CdSnSe4 shows a high laser-induced damage threshold (LIDT) of 0.7 GW cm−2. This special phenomenon is remarkable and may open a new avenue in searching for promising IR NLO materials with large LIDTs.

We reported the synthesis and crystal structures of alkali metal and alkali-earth metal phosphite, namely, CsV2(H3O)(HPO3)4 (1), and Ba3V2(HPO3)6 (2). Both compounds were prepared by hydrothermal reactions and feature unique new structures. They both exhibit 3D complicated frameworks based on VO6 octahedra which are connected by HPO3 tetrahedra via corner-sharing. Alkali or alkali earth metal cations are filled in the different channels of the frameworks. Topological analysis shows that the framework of CsV2(H3O) (HPO3)4 (1) is a new 3,3,3,4,5-connected network with the Schlafli symbol of {4.62}2{42.66.82}{63}{65.8}. The investigations of X-ray photoelectron spectroscopy (XPS) and magnetic measurement on CsV2(H3O)(HPO3)4 suggest a +3 oxidation state of the vanadium ions in compound 1. Photocatalytic performance was evaluated by photocatalytic H2 evolution and degradation of methylene blue, which shows that both compounds exhibit activity under visible-light irradiation. IR spectrum, UV–vis-NIR spectrum and thermogravimetric analysis (TGA) of compounds were also investigated.

A novel lanthanide germanate, namely RbNdGe2O6, has been successfully synthesized by high-temperature solid-state reaction in open air atmosphere for the first time. Single crystal X-ray diffraction indicates a 3D framework composed of 1D neodymium oxygen chains connected with cyclogermanate Ge3O9 units with Rb+ located in the internal space. X-ray powder diffraction coupled with Rietveld refinement reveals the sample’s phase purity we have prepared. Thermal behavior analysis shows RbNdGe2O6 is very stable, it doesn’t decomposition until heated up to 998 ​°C. UV–visible absorption and diffuse reflection spectrum feature characteristic absorption bands of f-electron transition and an optical bandgap value of 4.65 ​eV. Magnetic susceptibilities measurement gives significant antiferromagnetic interactions between magnetic centers. The photodegradation experiments were performed to evaluate photocatalytic activities of RbNdGe2O6. By using P25 as a reference, RbNdGe2O6 features to be an effective visible-light-driven catalyst in photodegrading methylene blue. Although the BET value of RbNdGe2O6 is only 3% that of P25, the photocatalytic activity reaches 0.55 times that of P25. Furthermore, the proposed photocatalytic mechanism which dominated by holes was further verified by adding ammonium oxalate as a quencher.

A mixed amines thiogermanate, namely (NH4)2[NH2(CH3)2]2Ge2S6 has been successfully synthesized by solvothermal reaction. Single crystal X-ray diffraction indicates the compound crystallizes in monoclinic space group P21/c with the lattice parameters: a = 6.9647(14) A, b = 15.719(3) A, c = 7.2042(14) A, β = 92.76(3)°. The structure features a zero-dimensional [Ge2S6]4− anions which are separated by NH4+ and [NH2(CH3)2]+. Hydrogen bond interactions play a crucial role in its structure formation. X-ray powder diffraction and TG-DSC measurements were performed to study its phase purity and thermal stability. UV–Vis diffuse reflectance spectroscopy coupled with Urbach fitting indicates an indirect optical transition semiconductor with a bandgap value of 3.50 eV. The result of first-principles electronic structure calculation supported the experimental indirect optical transition but the value was under estimated as 3.061 eV. Density of states and population analysis were also calculated to reveal the origin of the bandgap and bond interaction for its structure formation.

In this paper we report on the preparation of CuFeInTe3 and its thermoelectric properties. Optical diffuse reflectance and Raman scattering spectroscopies, as well as X-ray powder diffraction were also carried out. Unprecedented for CuFeInTe3, a direct and an indirect band gap were found from its absorption spectrum. From Hall effect measurements at 300 K the carrier concentration (n), electrical conductivity (σ) and mobility (μ) were determined. In order to investigate whether this material is suitable for thermoelectric applications, the Seebeck coefficient (S), the thermal conductivity (κ) and σ as a function of temperature were measured. The measurements of Hall and Seebeck coefficients showed that alloying CuInTe2 with Fe2+ produces a change from the original p-type to n-type conductivity and causes a decrease in the κ value, while leaving σ unchanged. Relatively large S values were found for CuFeInTe3, with respect to CuInTe2, which were explained on the basis of a probable electron effective mass increase due to Fe2+ incorporation. It was also found, that thermal and electrical conductivities decrease with increasing temperature in the range between 300 and 450 K, while the figure of merit (zT) reaches values of 0.075 and 0.126 at 300 and 450 K respectively. Thus, the zT of CuFeInTe3 increases with temperature, reaching values larger than those reported for CuInTe2.

High-temperature, solid-state synthesis in the Li2MnSnS4 system led to the discovery of two new polymorphic compounds that were analyzed using single crystal X-ray diffraction. The α-polymorph crystallizes in Pna21 with the lithium cobalt (II) silicate, Li2CoSiO4, structure type, where Z=4, R1=0.0349 and wR2=0.0514 for all data. The β-polymorph possesses the wurtz-kesterite structure type, crystallizing in Pn with Z=2, R1=0.0423, and wR2=0.0901 for all data. Rietveld refinement of synchrotron X-ray powder diffraction was utilized to quantify the phase fractions of the polymorphs in the reaction products. The α/β-Li2MnSnS4 mixture exhibits an absorption edge of ∼2.6–3.0 eV, a wide region of optical transparency in the mid- to far-IR, and moderate SHG activity over the fundamental range of 1.1–2.1 μm. Calculations using density functional theory indicate that the ground state energies and electronic structures for α- and β-Li2MnSnS4, as well as the hypothetical polymorph, γ-Li2MnSnS4 with the wurtz-stannite structure type, are highly similar.

Correction for ‘Infrared nonlinear optical properties of lithium-containing diamond-like semiconductors Li2ZnGeSe4 and Li2ZnSnSe4’ by Jian-Han Zhang et al., Dalton Trans., 2015, 44, 11212–11222.

Herein, unprecedented NLO-brominated tin hypophosphites, namely [Sn

The NLO semiconductor of title is quantitatively obtained by solid state reaction of stoichiometric amounts of Cd, Ge, S, and a slight excess of Li2S (graphite crucible in evacuated silica tube, 750 °C, 144 h).

A new alkali-metal borogermanate with noncentrosymmetric structure, namely, Cs2GeB4O9, has been discovered, and a large crystal with dimensions of 20 × 16 × 8 mm(3) has been grown by a high-temperature top-seeded solution method using Cs2O-B2O3 as a flux. The compound crystallizes in the tetragonal space group I4 with a = b = 6.8063(2) Å, c = 9.9523(7) Å, V = 461.05(4) Å(3), and Z = 2. It features a three-dimensional anionic open framework based on GeO4 tetrahedra and B4O9 clusters that are interconnected via corner-sharing, forming one-dimensional channels of nine-/ten-membered rings along the a and b axes, which are occupied by Cs(+) cations. Cs2GeB4O9 exhibits a very high thermal stability with a melting point of 849 °C, and it possesses a short-wavelength absorption edge onset at 198 nm determined by UV-vis transmission spectroscopy measurements on a slab of polished crystal. Powder second-harmonic generation (SHG) measurement on sieved crystals reveals that Cs2GeB4O9 is a type I phase-matchable material with a strong SHG response of about 2.8 × KH2PO4. The preliminary investigation indicates that Cs2GeB4O9 is a new promising second-order nonlinear-optical crystalline material.

CsV2(H3O)(HPO3)4 (I) and Ba3V2(HPO3)6 (II) are prepared by hydrothermal reaction of aqueous Cs2CO3 or BaCO3, NaVO3, and H3PO3 (autoclave, 210 °C, 4 d, pH 0.5→1; 83 and 85% yield, resp.).

Borogermanates are a class of very important compounds in materials chemistry. In this paper, the syntheses, structures, and properties of metal borogermanates are reviewed. Organically templated borogermanates with zeolite-like open-frameworks show potential applications as microporous materials. Many compounds in alkali or alkaline-earth borogermanate systems are structurally acentric or polar, some of which exhibit excellent Second Harmonic Generation (SHG) coefficients, wide transparency regions, and high optical-damage thresholds as well as excellent thermal stability. Most of the lanthanide borogermanates are structurally centrosymmetric and not SHG active; however, they are able to emit strong luminescence in visible or near-IR region. In the B-rich compounds, BO 3 and BO 4 groups can be polymerized into a variety of discrete polynuclear anionic cluster units or extended architectures via B–O–B bridges; whereas in the Ge-rich compounds, GeO 4 and GeO 6 polyhedra can also be polymerized. The combinations of borate and germinate afforded rich structural and topological types.

Two new acentric borogermanates, Ca(10)Ge(16)B(6)O(51) (Pba2) and Cd(12)Ge(17)B(8)O(58) (P4), have been successfully synthesized by high-temperature solid-state reactions of CaCO(3) (or CdCO(3)), GeO(2), and H(3)BO(3). Both structures display the same one-dimensional (1D) [Ge(4)O(12)](n) chains composed of GeO(4) tetrahedra and GeO(6) octahedra. In Ca(10)Ge(16)B(6)O(51), neighboring 1D [Ge(4)O(12)](n) chains are condensed into a two-dimensional (2D) [Ge(4)O(10.75)](n) layer via corner sharing, and such layers are further interconnected by "isolated" BO(4) tetrahedra and B(2)O(7) dimers into a three-dimensional (3D) framework, forming 1D tunnels of 5-, 6-, and 7-MRs along the c axis that are occupied by Ca(2+) cations. In Cd(12)Ge(17)B(8)O(58), neighboring 1D [Ge(4)O(12)](n) chains are interconnected into a [Ge(4)O(10.5)](n) open framework via corner sharing with large pores filled by big [Ge(B(2)O(7))(4)](28-) clusters, leading to formation of three types of 1D tunnels of 5-, 6-, and 7-membered rings (MRs) along the c axis which are occupied by the Cd(2+) cations. Both compounds are transparent in the range of 0.3-6.67 μm and exhibit very weak SHG responses.

Two new barium borogermanates with two types of novel structures, namely, Ba(3)[Ge(2)B(7)O(16)(OH)(2)](OH)(H(2)O) and Ba(3)Ge(2)B(6)O(16), have been synthesized by hydrothermal or high-temperature solid-state reactions. They represent the first examples of alkaline-earth borogermanates. Ba(3)[Ge(2)B(7)O(16)(OH)(2)](OH)(H(2)O) crystallized in a polar space group Cc. Its structure features a novel three-dimensional anionic framework composed of [B(7)O(16)(OH)(2)](13-) polyanions that are bridged by Ge atoms with one-dimensional (1D) 10-membered-ring (MR) tunnels along the b axis. The Ba(II) cations, hydroxide ions, and water molecules are located at the above tunnels. Ba(3)Ge(2)B(6)O(16) crystallizes in centrosymmetric space group P1. Its structure exhibits a thick layer composed of circular B(6)O(16) units connected by GeO(4) tetrahedra via corner sharing, forming 1D 4- and 6-MR tunnels along the c axis. Ba1 ions reside in the tunnels of the 6-MRs, whereas Ba2 ions are located at the interlayer space. Both compounds feature new types of topological structures. Second-harmonic-generation (SHG) measurements indicate that Ba(3)[Ge(2)B(7)O(16)(OH)(2)](OH)(H(2)O) displays a weak SHG response of about 0.3 times that of KH(2)PO(4). Optical, thermal stability, and ferroelectric properties as well as theoretical calculations have also been performed.

Three novel rubidium borogermanates with three types of noncentrosymmetric structures, namely, RbGeB(3)O(7), Rb(2)GeB(4)O(9), and Rb(4)Ge(3)B(6)O(17), have been synthesized by high-temperature solid-state reactions in platinum crucibles. The structure of RbGeB(3)O(7) features a three-dimensional (3D) anionic framework composed of cyclic B(3)O(7) groups corner-sharing GeO(4) tetrahedra. The structure of Rb(2)GeB(4)O(9) shows a 3D anionic framework based on B(4)O(9) clusters connected by GeO(4) tetrahedra via corner sharing. The structure of Rb(4)Ge(3)B(6)O(17) is a novel 3D anionic framework composed of cyclic B(3)O(8) groups, Ge(2)O(7) dimers, and GeO(4) tetrahedra that are interconnected via corner sharing. Second harmonic generation (SHG) measurements indicate that RbGeB(3)O(7), Rb(2)GeB(4)O(9), and Rb(4)Ge(3)B(6)O(17) display moderate SHG responses that are approximately 1.3, 2.0, and 1.3 × KH(2)PO(4) (KDP), respectively, which are slightly smaller than those from theoretical calculations (about 3.7, 2.8, and 2.4 × KDP, respectively).

Cu2CdSnS4 and α/β-Cu2ZnSiS4 meet several criteria for promising nonlinear optical materials for use in the infrared (IR) region. Both are air-stable, crystallize in noncentrosymmetric space groups, and possess high thermal stabilities. Cu2CdSnS4 and α/β-Cu2ZnSiS4 display wide ranges of optical transparency, 1.4–25 and 0.7–25 μm, respectively, and have relatively large second-order nonlinearity as well as phase matchability for wide regions in the IR. The laser-damage threshold (LDT) for Cu2CdSnS4 is 0.2 GW/cm2, whereas α/β-Cu2ZnSiS4 has a LDT of 2.0 GW/cm2 for picosecond near-IR excitation. Both compounds also exhibit efficient third-order nonlinearity. Electronic structure calculations provide insight into the variation in properties.

The synthesis, crystal structure, and characterizations of a new noncentrosymmetric vanadyl iodate NaVO2(IO3)2(H2O), are reported. NaVO2(IO3)2(H2O) crystallizes in the polar monoclinic space group P21 (No. 4) with a = 9.114(1) A, b = 5.2146(5) A, c = 9.216(1) A, and β = 111.298(8)°. It displays a unique layered structure composed of 1D right-handed helical chains of [(VO2)(IO3)2]− anions along the b-axis that are bridged by sodium(I) ions. The polarity in the structure is imparted by the alignment of the stereochemically active lone pairs of the iodate anions along the b-axis. On the basis of the powder second-harmonic generation (SHG) measurements, NaVO2(IO3)2(H2O) belongs to the phase-matchable class with a very large SHG response of approximately 20 × KH2PO4 (KDP) or about 800 × α-quartz, which is in good agreement with the results from the theoretical calculations.

Two new lithium-containing diamond-like semiconductors, Li2ZnGeSe4 and Li2ZnSnSe4, have been prepared by high-temperature, solid-state synthesis. Single crystal X-ray diffraction reveals that both compounds adopt the wurtz-kesterite structure type, crystallizing in the noncentrosymmetric space group Pn. X-ray powder diffraction coupled with Rietveld refinement indicates the high degree of phase purity in which the materials are prepared. Both compounds display optical bandgaps around 1.8 eV, wide optical transparency windows from 0.7 to 25 μm and type-I phase matched second harmonic generation starting at 2500 nm and persisting deeper into the infrared. Using the Kurtz powder method, the second-order nonlinear optical coefficient, χ((2)), was estimated to be 19 and 23 pm V(-1) for Li2ZnGeSe4 and Li2ZnSnSe4, respectively. Using a 1064 nm incident laser beam with a pulse width (τ) of 30 ps both compounds exhibit a laser damage threshold of 0.3 GW cm(-2), which is higher than that of the AgGaSe2 reference material measured under identical conditions. Differential thermal analysis shows that the title compounds are stable up to 684 and 736 °C, respectively. These properties collectively demonstrate that Li2ZnGeSe4 and Li2ZnSnSe4 have great potential for applications in tunable laser systems, especially in the infrared and even up to the terahertz regime. Electronic structure calculations using a plane-wave pseudopotential method within density functional theory provide insight regarding the nature of the bandgap and bonding.

The NLO semiconductor of title is quantitatively obtained by solid state reaction of stoichiometric amounts of Cd, Ge, S, and a slight excess of Li2S (graphite crucible in evacuated silica tube, 750 °C, 144 h).

Cu2CdSnS4 and α/β-Cu2ZnSiS4 meet several criteria for promising nonlinear optical materials for use in the infrared (IR) region. Both are air-stable, crystallize in noncentrosymmetric space groups, and possess high thermal stabilities. Cu2CdSnS4 and α/β-Cu2ZnSiS4 display wide ranges of optical transparency, 1.4-25 and 0.7-25 μm, respectively, and have relatively large second-order nonlinearity as well as phase matchability for wide regions in the IR. The laser-damage threshold (LDT) for Cu2CdSnS4 is 0.2 GW/cm(2), whereas α/β-Cu2ZnSiS4 has a LDT of 2.0 GW/cm(2) for picosecond near-IR excitation. Both compounds also exhibit efficient third-order nonlinearity. Electronic structure calculations provide insight into the variation in properties.

Single crystals of the title compounds are prepared by solid state reaction of K2CO3 or Ba(OH)2, Sb2O3, and H3BO3 (Pt crucibles, 850 °C, 33 h).

Two new boroantimonates, namely, KSbB2O6 and BaSb2B4O12, have been successfully synthesized through high-temperature solid state reactions. Their structures feature two types of novel anionic 3D frameworks composed of 1D chains of corner-sharing SbO6 octahedra that are interconnected by B2O5 groups. The 1D chains of corner-sharing SbO6 octahedra in polar KSbB2O6 (space group Cc) are extended along the c-axis, whereas those in the centrosymmetric BaSb2B4O12 (space group C2/c) are propagated along the [101] direction. The K(+) ions are located at the 1D tunnels of the anionic frameworks along both b- and c-axis, whereas Ba(2+) ions are located at the 1D tunnels of the anionic frameworks along both the a- and c-axis. KSbB2O6 is a polar material that displays weak SHG response, whereas BaSb2B4O12 is centrosymmetric and not SHG active. Studies on their optical properties, thermal stability, and band structure calculations based on DFT methods have been also performed.

Borogermanates are a class of very important compounds in materials chemistry. In this paper, the syntheses, structures, and properties of metal borogermanates are reviewed. Organically templated borogermanates with zeolite-like open-frameworks show potential applications as microporous materials. Many compounds in alkali or alkaline-earth borogermanate systems are structurally acentric or polar, some of which exhibit excellent Second Harmonic Generation (SHG) coefficients, wide transparency regions, and high optical-damage thresholds as well as excellent thermal stability. Most of the lanthanide borogermanates are structurally centrosymmetric and not SHG active; however, they are able to emit strong luminescence in visible or near-IR region. In the B-rich compounds, BO 3 and BO 4 groups can be polymerized into a variety of discrete polynuclear anionic cluster units or extended architectures via B–O–B bridges; whereas in the Ge-rich compounds, GeO 4 and GeO 6 polyhedra can also be polymerized. The combinations of borate and germinate afforded rich structural and topological types.

A family of new luminescent lanthanide MOFs have been synthesized and display a strong second-harmonic generation response, which is 6.0 times that of KDP and phase matchable. The LnMOFs also exhibit typical luminescence emissions with high quantum yields (up to 70.0% for Tb).

The first examples of lanthanide(III) organoarsonates, Ln(L(1))(H(2)O)(3) (Ln = La (1), H(3)L(1) = 4-hydroxy-3-nitrophenylarsonic acid), Ln(L(1))(H(2)O)(2) (Ln = Nd (2), Gd (3)), and mixed-ligand lanthanide(III) organoarsonates, Ln(2)(HL(1))(2)(C(2)O(4))(H(2)O)(2) (Ln = Nd (4), Sm (5), Eu (6)), were hydrothermally synthesized and structurally characterized. Compounds 1-3 feature a corrugated lanthanide arsonate layer, in which 1D lanthanide arsonate inorganic chains are further interconnected via bridging L(1)(3-) ligands. Compounds 4-6 exhibit a complicated 3D network. The interconnection of the lanthanide(III) ions by the bridging arsonate ligand leads to the formation of a novel 3D framework with long narrow 1D tunnels along the a-axis, with the oxalate anions are located at the above tunnels and bridging with lanthanide(III) ions. Compounds 2 and 4 exhibit the characteristic emission bands of the Nd(III) ion, whereas compound 6 displays the characteristic emission bands of the Eu(III) ion. The magnetic properties of compounds 3-6 were also investigated.

Single crystals of the title compounds are prepared by solid state reaction of CaCO3 or CdCO3, GeO2, and H3BO3 (Pt crucible, 980—1080 °C, 10—20 h).

The structures of the new title compounds (IV) (trigonal, space group P, Z = 1) and (V) (monoclinic, Cc, Z = 4) are determined by single crystal XRD.

RbGeB3O7 (I), Rb2GeB4O9 (II), and Rb4Ge3B6O17 (III) are prepared in quantitative yield by solid state reactions of Rb2O3, GeO2, and H3BO3 mixtures in a molar ratio of 1:2:6 (I), 1:1:4 (II), and 2:3:6 (III) (650 °C, 6 d, Pt crucible).

Light yellow hexagonal-shaped single crystals of the new title compound are hydrothermally synthesized from mixtures of NaVO3, Ga2O3, and I2O5 (H2O, autoclave, 200 °C, 4 d, 83% yield).

A series of new lanthanide borogermanates, namely, Ln(2)GeB(2)O(8) (Ln = Nd, Sm-Tb), have been synthesized by high temperature solid state reactions in platinum crucibles. They are isostructural and feature a layered [GeB(2)O(8)](6-) architecture built of 1D chains of corner-sharing BO(4)-tetrahedra that are further bridged by GeO(4)-tetrahedra. The lanthanide(III) ions are located at the interlayer space and are seven-coordinated. Results of magnetic measurements indicate Sm(III), Eu(III) and Gd(III) compounds display an antiferromagnetic interaction between Ln(III) centers whereas the Tb(III) compound exhibits a ferromagnetic interaction between Tb(3+) ions. Luminescent studies indicate that Eu(2)GeB(2)O(8) and Tb(2)GeB(2)O(8) emit strong red and green light, respectively.

A series of new alkali metal and alkali-earth metal phosphites, namely, NaIn3(HPO3)5(H2O)4, AIn(HPO3)2 (A = Rb, Cs) and Ba3M2(HPO3)6 (M = Al, Ga, In), have been synthesized by hydrothermal reactions. Their structures have been determined by single-crystal X-ray diffraction. The structure of NaIn3(HPO3)5(H2O)4 shows a complicated 3D anionic framework based on InO6 octahedra connected by HPO3 tetrahedra via corner-sharing, and the 3D anionic network of NaIn3(HPO3)5(H2O)4 can also be described as a new 3,5-net with a Schlafli symbol of {4.82}{42.6.87}{42.6}3{42.88}{43.62.85}{83}. Both AIn(HPO3)2 (A = Rb, Cs) feature a 2D layer composed by InO6 octahedral and HPO3 tetrahedral units with alkali metal cations filling the interlayer spaces. Ba3M2(HPO3)6 (M = Al, Ga, In) are isomorphous, and their structures feature a 3D anionic framework composed of MO6 (M = Al, Ga, In) octahedra and HPO3 tetrahedra interconnected via corner-sharing. IR and UV-vis spectra and TGA curves of these materials were also measured.

A new family of lanthanide metal–organic frameworks, LnL (Ln = Y, La–Yb, except Pm), were synthesized under hydrothermal conditions based on a semi-rigid trivalent carboxylic acid. All LnMOFs are isostructural based upon the analyses of single crystal and powder X-ray diffractions. The optical properties of compounds LnL can be easily tuned by doping methods, allowing for the syntheses of the materials with enhanced visible emission properties. Considering the intense blue-emission of the Dy compounds, it is expected that white light can be achieved by doping Dy and other red-emission lanthanide ions, such as Eu3+ or Sm3+. For the first time, without involving any emission from organic ligands, white-light emission was successfully realized by codoping Dy/Eu or Dy/Sm into analogic Gd compounds.

The first four metal boroselenites, namely, K2Se3B2O10, ASeB3O7 (A = Na, K), and Li2SeB8O15, have been synthesized by high temperature solid state reactions. Interestingly, the different cationic sizes and their coordination geometries led to three different types of anionic boroselenite frameworks ranging from a one-dimensional (1D) chain, to two-dimensional (2D) layers to a three-dimensional (3D) network. K2Se2B2O10 features a novel 1D [Se3B2O10]2− chain based on isolated B2O7 and SeO3 groups. ASeB3O7 (A = Na, K) feature a layered [SeB3O7]− architecture built of 1D corner-sharing B3O7 clusters that are further bridged by Se atoms. Li2SeB8O15 features an interesting 3D [SeB8O15]2− anionic framework composed of B3O7 groups and SeO3 units. Such 3D frameworks are further interpenetrated with each other into a 2-fold interpenetrating structure.

Six new phases in the alkali metal-Nb(V)/Ta(V)-Se(IV)/Te(IV)-O systems have been prepared by solid-state reactions at high-temperatures. Their structures were determined by single-crystal X-ray diffraction studies. AM(3)O(6)(QO(3))(2) (A = K, Rb, M = Nb, Ta, Q = Te; A = K, M = Nb, Q = Se) are isomorphous and their structures feature a 3D network with 1D 4- and 6-MRs tunnels along the a-axis which is composed of 2D layers of corner-sharing MO(6) octahedra bridged by QO(3) groups. The alkali metal ions are located at the above 1D tunnels of 6-MRs. The structure of Cs(3)Nb(9)O(18)(TeO(3))(2)(TeO(4))(2) features a thick Nb-Te-O layer built of corner-sharing NbO(6) octahedra, TeO(3) and TeO(4) groups. The 2D layer of the NbO(6) octahedra with 1D tunnels of 6-MRs along the c-axis are formed by 1D chains of NbO(6) chains along the c-axis and linear Nb(4)O(21) tetramers by corner-sharing. The TeO(3) and TeO(4) groups are grafted on both sides of the niobium-oxide layer via Nb-O-Te or/and Te-O-Te bridges. The caesium(i) ions are located at the above 1D tunnels of 6-MRs. TGA, UV-vis and infrared spectral measurements as well as electronic structure calculations have also been performed.