Recent development of metal borate halides: Crystal chemistry and application in second-order NLO materials

Photoluminescent carbon dots based on a rare 3D inorganic–organic hybrid cadmium borate crystal

A 3D inorganic–organic hybridized skeleton cadmium borate [Cden][B₅O₈(OH)] (1) (en = ethylenediamine) has been solvothermally synthesized. By calcining it, specific shape carbon dots (C-dots) with abundant free radicals were observed. In addition, C-dots in the ethanol phase exhibited variable photoluminescence and showed a special effect to Cr³⁺/Cs⁺ ions and CdSe/ZnS, CsPbBr₃ quantum dots.

Ba2ZnSc(BO3)3and Ba4Zn5Sc2(BO3)8: first examples of borates in the Zn–Sc–B–O system featuring special structure configurations

First examples in the Zn–Sc–B–O system featuring a special Zn/Sc–O configuration ([Zn₂(BO₃)₆]¹⁴⁻cluster, lowest-coordinated ScO₅polyhedra, and coexistence of ZnO₄and ZnO₆units).

Transition-metal complexes with oxidoborates. Synthesis and XRD characterization of [(H3NCH2CH2NH2)Zn{κ3 O,O′,O′′-B12O18(OH)6-κ1 O′′′}Zn(en)(NH2CH2CH2NH3)]·8H2O (en=1,2-diaminoethane): a neutral bimetallic zwiterionic polyborate system containing the ‘isolated’ dodecaborate(6−) anion

The title compound, [(H3NCH2CH2NH2)Zn{κ3 O,O′,O′′-B12O18(OH)6-κ1 O′′′}Zn(en)(NH2CH2CH2NH3)]·8H2O (en=1,2-diaminoethane) (1), was prepared as a crystalline solid in moderate yield from the reaction of B(OH)3 with [Zn(en)3][OH]2 in aqueous solution (15:1) ratio. The structure contains a neutral bimetallic complex comprised of a unusual dodecaborate(6−) anion ligating two [H3NCH2CH2NH2Zn(en)n]3+ centers in a monodentate (n=1) or tridentate (n=0) manner.

Finding the Next Deep-Ultraviolet Nonlinear Optical Material: NH4B4O6F

Nonlinear optical materials are essential for the development of solid-state lasers. KBe₂BO₃F₂ (KBBF) is a unique nonlinear optical material for generation of deep-ultraviolet coherent light; however, its industrial application is limited. Here, we report a new material NH₄B₄O₆F, which exhibits a wide deep-ultraviolet transparent range and suitable birefringence that enables frequency doubling below 200 nm. NH₄B₄O₆F possesses large nonlinear coefficients about 2.5 times that of KBBF. In addition, it is easy to grow bulk crystals and does not contain toxic elements.

Two Barium Gold Iodates: Syntheses, Structures, and Properties of Polar BaAu(IO3)5 and Nonpolar HBa4Au(IO3)12 Materials

Two new barium gold iodates, namely, BaAu(IO₃)₅ and HBa₄Au(IO₃)₁₂, have been prepared. BaAu(IO₃)₅ crystallizes in the polar space group Pca2₁, whereas HBa₄Au(IO₃)₁₂ crystallizes in the centrosymmetric space group P2₁/c. BaAu(IO₃)₅ consists of unique polar [Au(IO₃)₄]^- anions whose four iodate groups are located at both sides of the AuO₄ plane and the polarity points in the [001̅] direction. BaAu(IO₃)₅ displays strong second-harmonic-generation (SHG) effects about 0.6KTiOPO₄ (KTP) and is phase-matchable. Thermal properties, optical spectra analyses, and theoretical calculations are also reported.

Extending Unique 1D Borate Chains to 3D Frameworks by Introducing Metallic Nodes

Two novel alkali/alkaline-earth borates, Ba₆ [B₆ O₉ (OH)₆ ]₂ (H₃ BO₃ ) (1) and Li₇ MAlB₁₂ O₂₄ (M=Ba, Sr, Ca) (2 a-c), with 1D and 3D structures have been made hydrothermally and characterized. 1 features a rare 1D anionic chain built by hexaborate clusters of B₆ O₁₁ (OH)₆ ; each made of six BO₄ /BO₂ (OH)₂ tetrahedra. The anionic chains are embedded in the channels of a Ba₆ -based wheel-cluster open-framework. On the basis of the structural analyses of 1, by incorporating Al atoms as the linkers and tuning the reaction conditions, the novel anhydrous 3D aluminoborates (ABOs) 2 a-c have been successfully obtained, constructed from B₆ O₁₄ -based cluster chains and AlO₆ octahedra. The 3D ABO framework and 3D Ba-O-Li network are interpenetrated to give a final dense structure. The study not only realized the expansion of the structure from the 1D chain of 1 to the 3D dense ABOs 2 a-c, but also obtained the first 3D AlO₆ -containing ABOs made under hydrothermal conditions. Different from the previously known 4-connected zeolite-type ABOs, alternately arranged from AlO₄ tetrahedra and oxo-boron clusters, the AlO₆ octahedra in 2 a-c as the linkers join to six 1D B₆ O₁₄ -based cluster chains to produce 3D ABOs. The optical diffuse reflectance spectra reveal that 2 a-c have wide range transparency. In addition, the thermal property analysis proves that 2 a-c are congruently melting compounds and possess high thermostability.

Two excellent phase-matchable infrared nonlinear optical materials based on 3D diamond-like frameworks: RbGaSn2Se6 and RbInSn2Se6

Two new excellent phase-matchable MFIR NLO materials RbXSn₂Se₆ (X = Ga, In) with 3D diamond-like framework structures are reported.

Two deep-ultraviolet nonlinear optical alkaline-earth metal borates based on different types of oxoboron clusters

Two non-centrosymmetric alkaline-earth metal borates were synthesized, showing the layered structures constructed from different oxoboron clusters and potentially new candidates for deep-UV NLO materials.

Synthesis, XRD Studies and NLO Properties of [p-H2NC6H4CH2NH3][B5O6(OH)4]·1/2H2O and NLO Properties of Some Related Pentaborate(1-) Salts

The non-metal cation pentaborate(1−) salt [p-H₂NC₆H₄CH₂NH₃][B₅O₆(OH)₄]·1/2H₂O (1) was synthesised from B(OH)₃ and p-H₂NC₆H₄CH₂NH₂ and crystallized from aqueous solution. Compound 1 was characterized by thermal (TGA/DSC), spectroscopic (IR, NMR) and single-crystal X-ray diffraction methods and it was found to crystallize in the non-centrosymmetric point group P2₁. Powder SHG measurements on 1 and some related alkylammonium pentaborate salts, [NH₃CMe₂(CH₂OH)][B₅O₆(OH)₄], [NH₃CMe(CH₂OH)₂][B₅O₆(OH)₄] and [NH₃CHMeCH₂OH][B₅O₆(OH)₄], a substituted imidazolium salt, [1,2,3-Me₃C₃H₂N₂][B₅O₆(OH)₄], a substituted piperidinium salt, [(CH₂)₅NH(CH₂CH₂OH)][B₅O₆(OH)₄], and a substituted pyrrolidinium salt, [S-(+)-2-(HOCH₂)C₄H₇NH₂][B₅O₆(OH)₄], were determined. Compound 1 and all compounds, except [1,2,3-Me₃C₃H₂N₂][B₅O₆(OH)₄], showed some weak SHG activity with SHG efficiencies of 0.1–0.2 relative to that of KH₂PO₄ (KDP).

A new method for the preparation of a [Sn2(H2PO2)3]Br SHG-active polar crystal via surfactant-induced strategy

A new SHG-active polar crystal, [Sn₂(H₂PO₂)₃]Br, was prepared by surfactant-induced strategy.

Experimental and ab initio studies of two UV nonlinear optical materials

Two new acentric polyborates, Ba₃(OH)(B₉O₁₆)[B(OH)₃] and Ba_2.16Pb_0.84(OH)(B₉O₁₆)[B(OH)₃] have been synthesized hydrothermally. Their structures have been determined by single-crystal X-ray diffraction.

Na6Si3S8O: the first example of a sulfide silicate exhibiting unusual tri-polymerized [Si3S8O]6−units without S–O bonds

A new sulfide silicate – Na₆Si₃S₈O – featuring novel tri-polymerized [Si₃S₈O]⁶⁻units without common S–O bonds has been verified as a promising birefringent material.

A series of pentanary inorganic supramolecular sulfides (A3X)[MB12(MS4)3] (A = K, Cs; X = Cl, Br, I; M = Ga, In, Gd) featuring B12S12 clusters

A series of multinary thiogallate- or thioindate-closo-dodecaborates synthesized by solid state reactions demonstrate second-harmonic generation behaviors.

New lead(ii) borates in the PbO/PbF2/H3BO3ternary phase diagram: syntheses and structures of β-Pb6B10O21and Pb4B8O16

Regulating the B : Pb ratio results in a series of lead(ii) borates or lead borate fluorides.

M3V2B10O23 (M = Ca, Sr): two new vanadoborates with [V2B10O23]∞ double layers

Ca₃V₂B₁₀O₂₃ and Sr₃V₂B₁₀O₂₃ are isostructural and their main frameworks are novel “infinite” 2D [V₂B₁₀O₂₃]_∞ double layers which composed of an [B₅O₉]_∞ infinite layer and VO₄ tetrahedra.

The first quaternary diamond-like semiconductor with 10-membered LiS4rings exhibiting excellent nonlinear optical performances

New DLS–Li₄HgGe₂S₇with novel 10-MR LiS₄rings and excellent performances(concurrently large SHG coefficient and impressive LDT) is reported.

The structural diversity of halogen-centered secondary building units: two new mixed-metal borate halides with deep-ultraviolet cut-off edges

Categories of halogen-centered SBUs were investigated among borates to elaborate the role of halogen to enrich the structural diversity of borates.

Ban+2Znn(BO3)n(B2O5)Fn(n = 1, 2): new members of the zincoborate fluoride series with two kinds of isolated B–O units

Two new zincoborate fluorides were firstly reported containing isolated [BO₃]³⁻and [B₂O₅]⁴⁻groups, which are the first examples of two kinds of isolated B–O groups that coexist in one zincoborate halide.

Predicting Global Minimum in Complex Beryllium Borate System for Deep-ultraviolet Functional Optical Applications

Searching for high performance materials for optical communication and laser industry in deep-ultraviolet (DUV) region has been the subject of considerable interest. Such materials by design from scratching on multi-component complex crystal systems are challenging. Here, we predict, through density function calculations and unbiased structure searching techniques, the formation of quaternary NaBeBO3 compounds at ambient pressure. Among the four low-energy phases, the P63/m structure exhibits a DUV cutoff edge of 20 nm shorter than α-BaB2O4 (189 nm) - the best-known DUV birefringent material. While the P-6 structure exhibits one time second-harmonic generation efficiency of KH2PO4 and possesses excellent crystal growth habit without showing any layer habit as observed in the only available DUV nonlinear optical material KBe2BO3F2, whose layer habit limits its wide industrial applications. These NaBeBO3 structures are promising candidates for the next generation of DUV optical materials, and the structure prediction technique will shed light on future optical materials design.

Nonlinear optical response mechanism of noncentrosymmetric lead borate Pb6[B4O7(OH)2]3with three crystallographically independent [B4O7(OH)2]4−chains

Pb₆[B₄O₇(OH)₂]₃features three unique [B₄O₇(OH)₂]⁴⁻chains while lead cations and π-conjugated BO₃groups make contribution to the nonlinear optical effect.

Na9Sb(Ge2Q6)2(Q = S, Se): two new antimony(iii) quaternary chalcogenides with ethane-like [Ge2Q6]6−ligands

The changing character from different orientations of M–M bonds (M = Si, Ge) in quaternary chalcogenides was systematically studied.