A facile strategy to adjust the density of planar triangle units in lead borate–nitrates

Three novel lead(ii) borate–nitrates were obtained through a facile hydrothermal reaction by adjusting the concentrations of the starting materials.

β-BaGa[B4O8(OH)](H2O) and Ba4Ga[B10O18(OH)5](H2O): new barium galloborates featuring unusual [B4O8(OH)]5− and [B10O18(OH)5]11− clusters

Centrosymmetric β-BaGa[B₄O₈(OH)](H₂O) with a layered structure and polar Ba₄Ga[B₁₀O₁₈(OH)₅](H₂O) with a novel 3D framework structure have been reported.

Silver pyroarsonates obtained from Ag(I)-mediated in situ condensation of aryl arsonate ligands under solvothermal conditions

Four new layered silver(I) organoarsonates, namely, [Ag(3)(L(3))(CN)] (1) (H(2)L(3) = (PhAsO(2)H)(2)O), [Ag(3)(L(4))(CN)] (2) (H(2)L(4) = (2-NO(2)-C(6)H(4)-AsO(2)H)(2)O), [Ag(3)(HL(5))(H(2)L(5))] (3) (H(3)L(5) = 3-NO(2)-4-OH-C(6)H(3)-AsO(3)H(2)) and [Ag(2)(HL(5))] (4), were synthesized under solvothermal conditions. During the preparations of 1 and 2, condensation of organoarsonate ligands (H(2)L(1) = Ph-AsO(3)H(2); H(2)L(2) = 2-NO(2)-C(6)H(4)-AsO(3)H(2)) and the decomposition of acetonitrile molecules to cyanide anions occurred. Single crystals of H(2)L(4) ligand and compounds 1-4 were isolated, and their crystal structures have been determined by single crystal X-ray diffraction studies. In 1, the one-dimensional (1D) chains based on Ag(I) ions and {L(3)}(2-) anions are further interconnected by CN(-) into two-dimensional (2D) layers. In 2, adjacent Ag(I) ions within the silver(I) organoarsonate layer are further bridged by μ(4)-CN(-) anions with very short Ag···Ag contacts. In 3, the hexanuclear {Ag(6)O(12)} clusters are interconnected by bridging organoarsonate ligands into a silver(I) arsonate hybrid layer. In 4, the right-handed {Ag(4)O(4)} chains are further interconnected by organoarsonate ligands as well as additional Ag-O-Ag bridges into a novel silver(I) arsonate layer. Compounds 1 and 2 display red and orange-red emissions, respectively, which may be assigned to be an admixture of ligand-to-metal charge transfer (LMCT) and metal-centered (4d-5s/5p) transitions perturbed by Ag(I)···Ag(I) interactions. Upon cooling from room temperature to 10 K, compound 1 exhibits interesting temperature-dependent emissions.

Exploratory investigation of new SHG materials based on galloborates

Three new galloborates, namely, GaB(5)O(8)(OH)(2)(en)(2)·H(2)O (1), LiGa(OH)(BO(3))(H(2)O) (2), and Rb(2)Ga(B(5)O(10))(H(2)O)(4) (3), have been synthesized by hydrothermal reactions. Compound 1 is the first example of a galloborate that contains an organic component. It crystallizes in space group P2(1)/c, and its crystal structure exhibits an infinite zigzag chain consisting of [B(5)O(8)(OH)(2)](3-) anions and GaO(2)N(4) octahedra interconnected via corner sharing. Compound 2 crystallizes in space group P31c with a layered structure composed of GaO(4), LiO(4), and BO(3) building units. Compound 3 belongs to chiral space group C222(1); the basic building blocks of the structure are the [B(5)O(10)](5-) cluster anion and GaO(4) tetrahedron, which are interconnected to form a three-dimensional network with tunnels of Ga2B6 eight-membered rings (8-MRs) which are filled by Rb(+) cations and lattice water molecules. Interestingly, Rb(2)Ga(B(5)O(10))(H(2)O)(4) displays a moderate second-harmonic generation (SHG) response comparable to that of KH(2)PO(4) (KDP), and it is phase matchable. Band structure and optical property calculations for Rb(2)Ga(B(5)O(10))(H(2)O)(4) based on DFT methods were also performed.

PbPt(IO3)6(H2O): a new polar material with two types of stereoactive lone-pairs and a very large SHG response

A new polar material containing two types of stereoactive lone-pairs has been synthesized. The unique parallel alignment of the stereoactive lone-pairs on Pb(2+) cations and the synergistic effect of two types of stereoactive lone-pairs on I(5+) and Pb(2+) cations make it exhibit a very large second-harmonic generation response of about 8 × KDP (KH(2)PO(4)).

Electronic structures and optical properties of Ca5(BO3)3F: a systematical first-principles study

A first-principles study of the electronic structure, the linear optical properties and second-order NLO properties of calcium fluoroborate (Ca(5)(BO(3))(3)F, or CBF) crystal has been performed within density functional theory and the independent-particle approximation. The results indicate that the calculated birefringence Δn and the second-order susceptibilities are very coincident with the experimental measured values, and the χ((2)) curves show stronger anisotropy than the linear optical properties. Further analysis based on the spectral and spatial decomposition of χ((2)) reveals that the main sources of the SHG response of CBF are from the planar BO(3) groups (74%-77%) and Ca(2+) cations (23%-26%) and can be attributed to the interband electronic transition from the nonbonding O 2p states to the B 2p and Ca 4s4p states. The packing arrangement of BO(3) is the principal contributor to the significant differences among SHG tensors in CBF. Meanwhile, for a certain crystal CBF, the SHG tensors' trend can be the trend of the optical transition matrix elements, which are high when the corresponding subscript directions have more parallel BO(3) triangular planes in the structure.

A series of new phases in the alkali metal-Nb(V)/Ta(V)-Se(IV)/Te(IV)-O systems

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.

A series of new ternary and quaternary compounds in the Li(I)-Ga(III)-Te(IV)-O system

Systematic explorations of new compounds in the Li(I)-Ga(III)-Te(IV)-O system led to two new isomeric ternary gallium tellurites, namely, α-Ga(2)(TeO(3))(3) and β-Ga(2)(TeO(3))(3), and two new quaternary lithium gallium tellurites, namely, HLi(2)Ga(3)(TeO(3))(6)(H(2)O)(6) and Li(9)Ga(13)Te(21)O(66). α-Ga(2)(TeO(3))(3) is a noncentrosymmetric structure (I4̅3d) and displays a moderately strong second-harmonic-generation response that is comparable with that of KDP (KH(2)PO(4)). Its structure features a condensed three-dimensional (3D) network alternatively connected by GaO(4) tetrahedra and TeO(3) trigonal pyramids via corner sharing. β-Ga(2)(TeO(3))(3) is centrosymmetric (P6(3)/m) and features a 3D open framework composed of Ga(2)O(9) dimers bridged by TeO(3) groups with one-dimensional (1D) 12-MR channels along the c axis. Although both HLi(2)Ga(3)(TeO(3))(6)(H(2)O)(6) and Li(9)Ga(13)Te(21)O(66) crystallized in the same space group R3̅, they belong to different structure types. The structure of HLi(2)Ga(3)(TeO(3))(6)(H(2)O)(6) can be viewed as the 1D tunnels of the 3D gallium tellurite being occupied by Li(+) and H(+) ions whereas the structure of Li(9)Ga(13)Te(21)O(66) is a complicated 3D framework composed of alternating gallium tellurite layers and GaO(6) octahedral layers with Li(+) cations being located at the cavities of the structure. Optical diffuse-reflectance spectrum measurements indicate that all four compounds are insulators and transparent in the range of 300-2500 nm.

A series of new alkali metal indium iodates with isolated or extended anions

Systematic explorations of new phases in the A(I)-In(III)-I(V)-O system by hydrothermal reactions led to five new compounds, namely, AIn(IO(3))(4) (A = Li, Na), Rb(3)In(IO(3))(6) and A(2)HIn(IO(3))(6) (A = Rb, Cs). The structure of AIn(IO(3))(4) (A = Li, Na) contains one-dimensional [In(IO(3))(4)](-) chains separated by Li(+) or Na(+) cations. In both compounds, each In(3+) cation is octahedrally coordinated by six IO(3)(-) anions, neighboring In(3+) cations are interconnected by bidentate bridging iodate anions into 1D chains. The structures of Rb(3)In(IO(3))(6) and A(2)HIn(IO(3))(6) (A = Rb, Cs) all feature isolated [In(IO(3))(6)](3-) anions with alkali metal ions (and H(+) ions) as spacers. Both optical diffuse reflectance spectrum measurements and band structure calculations based on DFT methods indicate that LiIn(IO(3))(4), NaIn(IO(3))(4), and Rb(2)HIn(IO(3))(6) are insulators.