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Two rare-earth borate crystals, YZnB5O10 and GdZnB5O10, have been synthesized through a high-temperature spontaneous crystallization method, and the crystal structures have been determined by single-crystal X-ray diffraction studies for the first time. These two compounds are new members of the REMB5O10 (RE = rare-earth ion and M = divalent metal ion) family and both of them belong to the same space group, P21/n. Based on the UV-Vis-NIR spectroscopic results, both compounds exhibit DUV cut-off edges (<190 nm). Moreover, to better understand the relationship between the electronic structures and optical properties, first-principles based theoretical calculations were performed. [ABSTRACT FROM AUTHOR]

The controllable synthesis of layered LiMnO 2 with orthorhombic ( o -LiMnO 2 ), monoclinic ( m -LiMnO 2 ), and mixed phase structures (i.e., containing both m -LiMnO 2 and o -LiMnO 2 ) was successfully achieved using a one-step hydrothermal method. The effects of temperature, reaction time, Li/Mn molar ratio, and alkaline solution concentration on the synthesis of the monoclinic and orthorhombic phases were studied in detail. The microstructure and composition of the samples were characterized by X-ray diffraction (XRD), Transmission electron microscopy (TEM), inductively coupled plasma atomic emission spectroscopy (ICP-AES) and X-ray photoelectron spectroscopy (XPS). The different valence states of manganese in material m-LiMnO 2 ,o-LiMnO 2 and mixed phase LiMnO 2 were determined by redox titration method. TEM observations confirmed that these differently structured samples exhibit irregular shapes with grain diameters of ∼50–200 nm. Examination of the electrochemical performances of these samples using the galvanostatic method revealed that the as-synthesized m -LiMnO 2 exhibited a maximum discharge capacity of 219.8 mAh·g −1 at 0.1C after several cycles, but exhibited poor cycling behavior. In contrast, o -LiMnO 2 exhibited the lowest discharge capacity of 180 mAh·g −1 , while demonstrating enhanced cycling stability. The mixed phase containing both m -LiMnO 2 and o -LiMnO 2 exhibited characteristics corresponding to both structures, namely a good cycling stability and a good discharge ability. [ABSTRACT FROM AUTHOR]

A congruent melting compound LiNaV2O6 has been synthesized by high-temperature solution reaction and it has been grown with sizes up to 11 × 6 × 2 mm3 by the top-seeded growth method for the first time. LiNaV2O6 crystallizes in the monoclinic system with space group C2/c, with a = 10.184(2) Å, b = 9.067(2) Å, c = 5.8324(11) Å, β = 108.965(14)°. UV–Vis–NIR diffuse reflectance spectrum of LiNaV2O6 shows that it has a wide transmittance range from 385 to 2500 nm. The ab initio calculations show that the birefringence of LiNaV2O6 is 0.136 at 589.3 nm. Therefore, LiNaV2O6 may be a new birefringent material. Based on the analysis of the relationship between crystal structure and linear optical properties, it is found that the large birefringence is attributed to the particular arrangement of V–O anionic groups. [ABSTRACT FROM PUBLISHER]

A coordination polymer, {[Cd(HMebpz)(ntcaa)(HO)]·HO} ( 1), has been synthesized by hydrothermal reaction of cadmium sulfate octahydrate with a flexible ligand, 3, 3′, 5, 5′-tetramethyl-4, 4′-bipyrazole and an auxiliary O-donor ligands, naphthalene-4,5-dicarboxylic acid-1,8-anhydride. Naphthalene-4,5-dicarboxylic acid-1,8-anhydride comes from the in situ dehydration of the naphthalene-1,4,5,8-tetracarboxylic acid in the hydrothermal reaction. Complex 1 exhibits a 2D wave-like layer structure based on tetranuclear CdO cluster units. The 2D wave-like layers are further held together by face-to-face π- π interactions between the naphthalene rings and intermolecular hydrogen bonds to generate a 3D supra-molecular network. The luminescent property of complex 1 was investigated in the solid-state at room temperature. Graphical Abstract: [Figure not available: see fulltext.]. [ABSTRACT FROM AUTHOR]

A 1-D helical tubular cadmium coordination polymer, [Cd(H2Me4bpz)(H2bidc)2]n (1, H2Me4bpz = 3,3′,5,5′-tetramethyl-4,4′-bipyrazole; H3bidc = benzimidazole-5,6-dicarboxylic acid) was hydrothermally synthesized and characterized by means of elemental analyses, PXRD, IR, 2D IR correlation spectra, solid UV, TG analysis, luminescence spectroscopy and single crystal X-ray diffraction. The crystal structure of 1 is a unique example of a 1D helical tube-in-tube structure. Interestingly, the [Cd(H2Me4bpz)] coordination helical tube is included in the [Cd(H2bidc)] supramolecular helical tube with the same handness. The compound displays a green luminescence upon excitation at 397 nm. [ABSTRACT FROM AUTHOR]

Three new metal-organic frameworks (MOFs), namely [Zn(tib)(PDC)] ( 1), [Zn3(tib)2(CHDC)3]·8H2O ( 2) and [Zn3(tib)2(BTC)2]·4.95H2O ( 3) were synthesized by hydrothermal reactions of ZnCl2 with 1,3,5-tris(1-imidazolyl)benzene (tib) and different carboxylate ligands of 2,6-pyridinedicarboxylic acid (H2PDC), 1,4-cyclohexanedicarboxylic acid (H2CHDC) and 1,3,5-benzenetriacetic acid (H3BTC), respectively. The complexes were characterized by IR, thermogravimetric analysis, single crystal and powder X-ray diffractions. Complex 1 has a binuclear structure, in which one imidazole group of tib is free of coordination, while 2 has three-dimensional (3D) framework with the CHDC-Zn microcycles filled into the tib-Zn 3D net, and 3 is a 2-fold interpenetrating 3D framework with the interconnection of two one-dimensional (1D) chains formed by BTC-Zn and tib-Zn, respectively. The different structures of 1- 3 are resulted from the distinct carboxylate ligands. In addition, complexes 1- 3 show obvious emissions at room temperature in the solid state. [ABSTRACT FROM AUTHOR]

Abstract: Three new coordination complexes [Mn(L)(H2O)2](1,4-BDC)·2H2O (1), [Mn(L)0.5(1,4-BDC)]CH3OH·H2O (2) and [Mn(L)(H2O)2](1,2-HBDC)2·2H2O (3) were synthesized by solvothermal reactions of 1,2,4,5-tetrakis(imidazol-1-ylmethyl)benzene (L) and 1,4-benzenedicarboxylic acid (1,4-H2BDC) or 1,2-benzenedicarboxylic acid (1,2-H2BDC) with Mn(II) salt, and characterized by single crystal X-ray diffraction, IR, thermogravimetric and elemental analyses. In complexes 1 and 3, each ligand L links four Mn(II) atoms to form two-dimensional (2D) cationic network with non-coordinated 1,4-BDC2− and 1,2-HBDC− anions lying in the voids between the two adjacent layers, respectively. The 2D layers are further connected together by hydrogen bonds to give three-dimensional (3D) supramolecular structures. However, the 1,4-BDC2− in 2 acts not only as counteranion, but also as bridging ligand leading to the formation of 2-fold interpenetrated 3D framework with pcu (primitive cubic unit) topology. The Mn(II) atoms bridged by carboxylate groups in 2 show antiferromagnetic interactions. [ABSTRACT FROM AUTHOR]

Nano structured LiMnBO 3 /C cathode materials are synthesized by a fast microwave solid-state reaction method using MnCO 3 , Li 2 CO 3 , H 3 BO 3 and glucose as starting materials for the first time. The crystal structure, morphology and electrochemical properties of LiMnBO 3 /C composites are characterized by X-ray diffraction (XRD), raman spectroscopy (Ramon), scanning electron microscopy (SEM), transmission electron microscopy (TEM), cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and charge–discharge tests. The result shows that not only monoclinic LiMnBO 3 /C but also hexagonal LiMnBO 3 /C cathode materials can be successfully synthesized by microwave solid-state method with power of 240 W in different time. Compared with h -LiMnBO 3 /C and mixed phase LiMnBO 3 /C, m -LiMnBO 3 /C displays lower charge-transfer resistance and the Warburg impedance, so it reveals a higher first discharge capacity of 156.3 mAh g −1 at 0.05 C within 1.8V–4.6 V, The value increases up to 173.2 mAh g −1 caused by the activation process. Even after 50 cycles, the discharge capacity of m-LiMnBO 3 /C still remains at 148.2 mAh g −1 . [ABSTRACT FROM AUTHOR]

Ni(L)2 (1) and Zn2(μ-OL)2(L)2 (2), (HL=S-benzyl-β-N-(2-bromobenzylidene) dithiocarbazate), were synthesized and characterized by elemental analysis and X-ray single-crystal diffraction analysis. 1 is a mononuclear neutral nickel(II) complex and the center nickel atom is chelated by donors of N2S2 possessing a distorted tetrahedral configuration, while in 2, the adjacent two complex molecules are linked through two O atoms to form a dimer and the center zinc atom is five-coordinate in a distorted trigonal-bipyramidal geometry. The cytotoxic activity study indicated that 2 showed potent cytotoxic activity against the human liver hepatocellular carcinoma (HepG2) cancer cell lines, with IC50 2.4±0.2μg·mL−1, which is slightly weaker than 5-fluoroacil (5-FU) (0.89±0.21μg·mL−1) as reference. A gel electrophoresis assay demonstrated the ability of the complex to cleave the pBR322 plasmid DNA. [ABSTRACT FROM AUTHOR]

A new member of the cuspidine family without the structural disorder, Na 2 Mg 2 P 2 O 7 F 2 exhibits an intricate three-dimensional framework that consists of the 2D herring-shaped layers [Mg 4 O 12 F 2 ] ∞ and the 1D s-shaped chain [Na 2 O 8 F 3 ] ∞ interlinked by isolated P 2 O 7 groups via sharing edge or vertex. [Display omitted] • A new member of the cuspidine family, Na 2 Mg 2 P 2 O 7 F 2 without the structure disorder was prepared by targeted structural modulation. • Na 2 Mg 2 P 2 O 7 F 2 exhibits an intricate three-dimensional (3D) framework that consists of the 2D herring-shaped layers [Mg 4 O 12 F 2 ] ∞ and the 1D s-shaped chain [Na 4 O 18 F 6 ] ∞ interlinked by isolated P 2 O 7 groups. • It can be seen that the larger size difference Δ R enables Na 2 Mg 2 P 2 O 7 F 2 to overcome the structural disorder, which is conducive to the exploration of new structures in phosphates fluoride. • Na 2 Mg 2 P 2 O 7 F 2 with cuspidine type has a large band gap (7.1 eV) and the structural template cuspidine is suitable for exploring UV/DUV optical materials. A new alkali/alkali-earth metal pyrophosphate fluoride Na 2 Mg 2 P 2 O 7 F 2 without the structural disorder in the cuspidine family has been successfully prepared in the sealed system. Na 2 Mg 2 P 2 O 7 F 2 crystallizes in the space group P 2 1 / c (No. 14) of the monoclinic crystal system. The structure of Na 2 Mg 2 P 2 O 7 F 2 is shown to be an intricate three-dimensional (3D) framework that consists of the 2D layers [Mg 4 O 12 F 2 ] ∞ and the 1D chain [Na 2 O 8 F 3 ] ∞ interlinked by isolated P 2 O 7 groups, which demonstrates the precise coordination environment of cations and the framework in inorganic alkali/alkaline earth metal pyrophosphate fluoride. By comparing with other phosphate structures, we found that the introduction of F is conducive to the consistent arrangement of anionic group P 2 O 7 and enriches the diversity of cationic polyhedra. In addition, first-principle theoretical studies were also carried out to aid the understanding of microstructures, and Na 2 Mg 2 P 2 O 7 F 2 possesses a large band gap (7.1 eV) and has potential applications in the deep ultraviolet region. [ABSTRACT FROM AUTHOR]

A new hydrated borate Cs 2 B 4 O 5 (OH) 4 with isolated B 4 O 5 (OH) 4 anionic groups and short UV cutoff edge (< 200nm). [Display omitted] • A new member of cesium borate, Cs 2 B 4 O 5 (OH) 4 was synthesized using the solid-state method. • Cs 2 B 4 O 5 (OH) 4 features a 3D network based on 2D [Cs 2 O 12 ] ∞ layers interconnected by [B 4 O 5 (OH) 4 ] anions group. The [B 4 O 5 (OH) 4 ] groups can be linked by hydrogen bonds to form the 1D chain. • The cut-off edge is below 200 nm which has potential application value in the UV region. A new hydrated cesium borate, Cs 2 B 4 O 5 (OH) 4 was synthesized successfully in a vacuum system. It crystallizes in the monoclinic space group P 2 1 / c with unit cell of dimensions a = 7.6907(6) Å, b = 13.2044(12) Å, c = 9.3636(7) Å, β = 94.211(3) °, V = 948.32(13) Å3, Z = 3. It takes [B 4 O 5 (OH) 4 ]2− polyborate anions as the fundamental building blocks (FBB) which are combined through the Cs-O polyhedra to form a three-dimensional (3D) network. The UV–vis-NIR spectrum shows that Cs 2 B 4 O 5 (OH) 4 possesses an ultraviolet (UV) cut-off edge below 200 nm which indicates that it may be applied in the UV region. In addition, the relationship between the structure and optical properties of this compound have been studied. The calculated band structures and the density of states indicate that Cs 2 B 4 O 5 (OH) 4 is a direct band gap compound with a band gap of 5.14 eV and the moderate birefringence. [ABSTRACT FROM AUTHOR]

Two novel lanthanide−sulfate compounds, [Ln 2 (SO 4 ) 3 (H 2 O) 8 ] (Ln = Tb ( 1 ) and Dy ( 2 )), have been synthesized under hydrothermal reactions. X-ray crystal structure analyses reveal that 1 and 2 are isomorphous and crystallize in monoclinic C 2 /c pace group, showing a layered structure. The layers bear a rare quasi-honeycomb metal arrangement, which is fastened by μ 3 = η 1 : η 1 : η 1 and μ 2 = η 1 : η 1 sulfates. If assigning the μ 3 = η 1 : η 1 : η 1 sulfate as a 3-connected node and the Ln 3+ ion as a 4-connected node, the network can be rationalized as a binodal (3,4)-connected V 2 O 5 topology with a Schäfli symbol of (4 2 ·6 3 ·8) (4 2 ·6). In addition, the infrared, thermogravimetric analysis and luminescent properties were also studied. Complexes 1 and 2 exhibit outstanding thermal stability and characteristic terbium and dysprosium luminescence. [ABSTRACT FROM AUTHOR]

Three new Mn(II) and Cd(II) coordination polymers with kgd network topology, namely, [Mn3(T4)2(DEF)6]·2H2O (1), [Mn3(T4)2(DMSO)2(CH3OH)4]·2CH3OH·3H2O (2) and [Cd3(T4)2(DMF)6]·5CH3OH·3DMF·H2O (3), have been prepared by reactions of tris[4-(1H-tetrazol-5-yl)phenyl]amine (H3T4) with corresponding metal salt and characterized by single crystal and powder X-ray diffractions, IR and thermogravimetric analyses. In compounds 1 and 3, the layers adopt center to center stacking, while there is a slight shifting between the adjacent layers in compound 2. Complexes 1 and 2 exhibit overall weak antiferromagnetic coupling between the neighboring Mn(II) atoms, and compound 3 shows luminescent property in the solid state at room temperature. [ABSTRACT FROM AUTHOR]

Abstract: Two manganese complexes containing 4,4′-bipyridine and methyl benzoate as ligands have been prepared and crystallized by solvent evaporation method in DMF. The single crystal X-ray crystallographic analyses reveal that the complexes crystallize in monoclinic system. Crystal of 1 [Mn2(4,4′-bipy)2 (o-MBA)4]n has space group of P21/c with unit cell parameters of a =17.508(Å), b =11.6229(Å), c =27.983(Å), β =128.123°, V =4.4797nm3, empirical formula: C52H44Mn2N4O8, Mr =962.79, Z =4, Dc =1.428g/cm3, μ =0.625mm−1, and F(000)=1992. The crystal of 2 [Mn (4,4′-bipy)(m-MBA)2]n belongs to space group C2/c with a =16.079(Å), b =11.652(Å), c =24.887(Å), β =92.02°, V =4.660nm3, empirical formula: C26H22MnN2O4, Mr =481.40, Z =8, Dc =1.372g/cm3, μ =1.179mm−1, F(000)=1992. The weak interactions in structures are observed from the X-ray crystallographic data. These include the CO hydrogen bonds, π–π stacking and Cπ interactions found in 1. The different strength of intermolecular interaction in the structures is reflected on their different thermal stability of the two complexes measured by thermal gravimetric analysis and the 2D-IR correlation spectroscopy. The study of weak interactions is meaningful to provide supporting data for potential application in molecular biology. [Copyright &y& Elsevier]

Abstract: Four new coordination complexes [Cd(DPBA-3)2(H2O)2](ClO4)2·2H2O (1), [Cd(DPBA-3)(DMF)(NO3)2]·DMF (2), [Cd3(DPBA-3)2(SCN)6]·2DMF·4H2O (3) and [Zn(DPBA-3)(SCN)2] (4) [DPBA-3= N,N′-di(pyridin-3-yl)pyridine-3,5-dicarboxamide] have been synthesized and characterized by elemental analysis, IR and single crystal X-ray diffraction. Complexes 1, 3 and 4 exhibit three different types of one-dimensional (1D) chain structures constructed by the metal ions and DPBA-3 ligands, and the Cd(II)-DPBA-3 1D chains in 3 are further linked by bridging SCN− ligands to afford a three-dimensional (3D) framework. Complex 2 possesses a (6,3) two-dimensional (2D) layer structure. In 1–4, the hydrogen bonds involving the amide groups play important role to stabilize the resultant frameworks. The photoluminescence properties of the DPBA-3 and the complexes were studied in the solid state at room temperature. [Copyright &y& Elsevier]

Six new coordination polymers [Zn2(L)(OX)2] (1), [Zn2(L)(1,2-BDC)2]·2H2O (2), [Zn2(L)(1,3-BDC)2(H2O)] (3), [Zn(L)(1,4-BDC)] (4), [Zn2(L)(BPDA)2]·2.68H2O (5), and [Zn3(L)2(BTC)2(H2O)2]·3H2O (6) were obtained by hydrothermal reactions of zinc(II) sulfate heptahydrate with rigid ditopic ligand 1,4-di(1H-imidazol-4-yl)benzene (L), sodium hydroxide, or tetrabutylammonium hydroxide and the corresponding carboxylic acid, namely, oxalic acid, 1,2-benzenedicarboxylic acid, 1,3-benzenedicarboxylic acid, 1,4-benzenedicarboxylic acid, 4,4′-biphenyldicarboxylic acid, or 1,3,5-benzenetricarboxylic acid, respectively. The complexes were characterized by single-crystal X-ray diffraction, IR, thermogravimetric, and elemental analyses. Complexes 1 and 2 are three-dimensional (3D) frameworks with infinite two-dimensional (2D) networks pillared by L ligands, and 1 possesses rare self-penetrating mab topology, while 2 shows ins topology. Complex 3 is a 2D bilayer network with infinite one-dimensional double Zn(II)-1,3-BDC2− chains linked by L ligands. Complexes 4−6 have multifold interpenetrating 3D structures: 4 has a 5-fold interpenetrating dia net, 5 has a 4-fold interpenetrating elongated primitive cubic α-Po structure, and 6 has a 3-fold interpenetrating framework. The results showed that the structural diversity of the complexes resulted from the different carboxylate ligands. Solid state properties such as photoluminescence and thermal stability of the complexes have been investigated. Six novel coordination polymers have been successfully constructed from reactions of rigid ditopic imidazole-containing ligand in the presence of different carboxylate ligands with Zn(II) salts. The photoluminescence properties of the complexes were explored. [ABSTRACT FROM AUTHOR]