Na₄[B₆O₉ (OH)₃](H₂O) Cl: A Deep-Ultraviolet Transparent Nonlinear Optical Borate Chloride with {[B₆O₉ (OH)₃]^3–}_∞ Chains

The development of nonlinear-optical (NLO) crystals with short ultraviolet cutoff edges is significant and challenging. Here, a new sodium borate chloride, Na4[B6O9 (OH)3](H2O) Cl, was successfully obtained by the mild hydrothermal method, which crystallizes in a polar space group Pca21. The structure of the compound is characterized by {[B6O9 (OH)3]3–}∞ chains. Measurements of optical properties indicate the compound exhibits a deep-ultraviolet (DUV) cutoff edge (≤200 nm) and moderate second harmonic generation response (0.4 × KH2PO4). It presents the first DUV hydrous sodium borate chloride NLO crystal and the first sodium borate chloride possessing a one-dimensional B–O anion framework. Probing into the connection of structure and optical properties has been performed based on theoretical calculations. These results are instructive for designing and obtaining new DUV NLO materials

Organic Cation Modulation Triggered Second Harmonic Response in Manganese Halides with Bright Fluorescence

Zero-dimensional (0D) hybrid manganese halides have been recently synthesized and exhibited rich functional properties including fluorescence, ferroelectrics, and ferromagnetism. However, few studies on second-harmonic generation (SHG) behaviors of manganese halide crystals have been reported, presumably owing to the d–d transitions. Here, we report three manganese bromides, [TEA]2MnBr4 (TEA+ = tetraethylammonium; 1), [BTEA]2MnBr4 (BTEA+ = benzyltriethylammonium; 2), and [BTMA]2MnBr4 (BTMA+= benzyltrimethylammonium; 3), with linear and nonlinear optical properties via benzyl or ethyl/methyl substitution strategies. They feature 0D structures containing isolated [MnBr4]2– anions and quaternary ammonium cations with different sizes inserted for charge balance. They all show green phosphorescence, and 2 possesses good luminescence efficiency with a quantum yield of 97.8%, which is larger than those of 1 (79%) and 3 (72%). Specifically, acentric 1 and 3 present effective SHG responses about 0.48 and 0.59 times that of KDP, respectively. The result throws light on the new properties of the hybrid manganese halides and provides a new way to develop novel nonlinear optical-active organic–inorganic hybrid metal halides

Noncentrosymmetric Ba₆In₂Q₁₀ (Q = S, Se): Structural Chemistry and Nonlinear-Optical Activity

The indispensable condition for laser frequency-doubling crystal materials is that they crystallize in the noncentrosymmetric (NCS) structures. Here, ternary NCS Ba6In2S10 (1) and Ba6In2Se10 (2) (P63) were synthesized via conventional solid-state reactions. Their zero-dimensional structures feature isolated InQ4 tetrahedra and Q22– (Q = S, Se) dimers that are separated by Ba2+ counter cations. The structural relevance and differences with the centrosymmetric Ba12In4S19 and Ba12In4Se20 are analyzed in detail. Both 1 and 2 show obvious laser frequency-doubling activity, and their optical band gaps are 3.72 and 1.78 eV, respectively. This work provides a new type of IR nonlinear-optical materials

From Ba₃Nb₂O₂F₁₂(H₂O)₂ to Ba_0.5NbO₂F₂(H₂O): Achieving Balanced Nonlinear Optical Performance by O/F Ratio Regulation

Metal oxyhalides have attracted extensive attention as fascinating nonlinear optical (NLO) materials. Here, two barium niobium oxyfluorides, Ba3Nb2O2F12(H2O)2 (1) and Ba0.5NbO2F2(H2O) (2), have been obtained by regulating the O/F ratio in Nb–O–F units (NbOF6 pyramids to NbO4F2 octahedra). The overall NLO effect is improved from 1 to 2 with larger second-harmonic generation (SHG) intensities (0.9 to 1.7 × KH2PO4 (KDP)) and maintainable large band gaps (>3.0 eV) by regulating the O/F ratio in Nb–O–F units (1:6 to 4:2)

Polyhedral Oligomeric Silsesquioxane (POSS) as Reinforcing Agent for Waterborne Polyurethane Coatings on Wood

Polyhedral oligomeric silsesquioxane (POSS) was added as a reinforcing agent in waterborne polyurethane (WPU)-based coatings to improve their properties. The morphology, structure, thermal stability as well as mechanical properties of the resulting WPU and WPU/POSS hybrid films were investigated. The good compatibility of POSS in the WPU matrices was demonstrated by transmission electron microscopy. Furthermore, Fourier-transform infrared spectroscopy analysis (FTIR) suggested the successful bonding of POSS and WPU matrices. The thermal stability of WPU/POSS hybrids was improved than that of pure WPU according to thermal gravimetric analysis (TGA). The results also revealed the enhancement of the pencil hardness and abrasion resistance of the hybrid films compared with WPU. However, the pull-off adhesion slightly decreased from Grade 0 to Grade 2.</div

Headspace Microextraction of Sulfonamides from Honey by Hollow Fibers Coupled with Ultrasonic Nebulization

A new method for the rapid simultaneous determination of five sulfonamides in honey was developed using ultrasonic nebulization-assisted extraction coupled with hollow fiber liquid–liquid–liquid microextraction prior to liquid chromatography. In the present method, the sample solution was nebulized by ultrasonication. Sulfonamides in the aerosol particles were extracted by 1-octanol impregnated in the pores of a hollow fiber and further into the acceptor phase (acid solution, pH 2.0) contained in the lumen of the hollow fiber. Several experimental parameters that affect the extraction efficiency were optimized. The present method provides good recoveries (88.9–114.2%) and acceptable precision (<10.7%), indicating the effective extraction. The detection limits were 4.6–6.8 μg/kg, lower than the maximum residue limits of sulfonamides in honeys. Compared to the traditional extraction methods, the present method requires less organic solvent and operation time, demonstrating excellent cleanup ability and good enrichment efficiency

Three-in-One Tetrahedral Functional Units Constructing Diamondlike Ag₂In₂SiS_3.06Se_2.94 with High-Performance Nonlinear-Optical Activity

Exploration of new functional materials with enhanced performance from known ones is always an attractive strategy. A new infrared (IR) nonlinear-optical (NLO) mixed chalcogenide Ag2In2SiS3.06Se2.94 (1), was obtained through partial congener substitution originated from Ag2In2SiS6 (0). 1 crystallizes in the monoclinic space group Cc, and its three-dimensional (3D) polyanionic network is composed of {[In4Si2Se5(S/Se)11]12–}∞ helical chains sharing S/Se(5) corner atoms with cavities embedded with counterion Ag+ ions. It exhibits a much enhanced NLO response compared to that of 0, reaching 1.1 × AgGaS2. Further theoretical analysis results indicate that the large NLO response can be attributed to the synergistic effect of AgQ4 and InQ4 tetrahedral functional motifs. This work not only reports a new high-performance IR NLO material but also enriches the partial ion substitution strategy to obtain new functional materials

Two New (3,6)-Connected MOFs with <i>eea</i> Topology and High CH₄ Uptake

Two new (3,6)-connected and <i>eea</i> topological MOFs without open metal sites, NJU-Bai30 and NJU-Bai31, from Cu-paddelwheel units and 5-[4′-(pyridin-4-yl)­phenyl]­isophthalic acid (L₁) and 5-[3′-amino-4′-(pyridin-4-yl)­phenyl]­isophthalic acid (L₂) have been synthesized, and interestingly, they exhibit relatively high surface area and large CH₄ adsorption uptake

Tellurium(IV) Halide Achieving Effective Nonlinear-Optical Activity: The Role of Chiral Ligands and Lattice Distortion

Chiral organic–inorganic hybrid metal halides are a promising class of nonlinear-optical materials with unique optical properties and flexible crystal structures. However, the structures and properties of chiral hybrid tellurium halides, especially second harmonic generation (SHG), have not been reported. Here, by introducing chiral organic molecule (R/S)-methylbenzylammonium (R/S-MBA), we synthesized a pair of novel zero-dimensional (0D) chiral tellurium-based hybrid halides with noncentrosymmetric space group C2, (R/S-MBA)2TeCl6 (R/S-Cl). Single-crystal X-ray diffraction analysis and solid-state circular dichroism (CD) spectra confirm that R/S-Cl shows obvious enantiomer enrichment. Moreover, the resulting chiral products present an efficient SHG response. Interestingly, through manipulation of halogen atoms, two pairs of achiral tellurium halides, (R/S-MBA)2TeBr6 (R/S-Br) and (R/S-MBA)2TeI6 (R/S-I), were obtained, both of which crystallize in the centrosymmetric space group R3̅. It is noteworthy that R/S-I has a narrow band gap of 1.55 eV, which is smaller than that of most 0D metal halides and comparable to that of three-dimensional lead halide, showing its potential as a highly efficient light absorber

KHg₄Ga₃S₉: A Hg-Based Sulfide with Nonlinear-Optical Activity in the A–M^II–M^III–Q (A = Alkali Metal; M^II = d¹⁰ Metal; M^III = Ga, In; Q = S, Se) System

The search for new high-performance infrared (IR) nonlinear-optical (NLO) materials is a hot topic in the fields of laser chemistry and inorganic solid-state chemistry. Here, a new Hg-based sulfide KHg4Ga3S9 in the family of A–MII–MIII–Q (A = alkali metal; MII = d10 metal; MIII = Ga, In; Q = S, Se) was synthesized. It crystallizes in the orthogonal system of the C2221 structure, which is rare for IR NLO chalcogenides. Its anionic framework {[Hg4Ga3S9]−}∞ is constructed by two types of interconnected helical chains, viz., the inner layer ({[Hg6Ga2S29/3]4/3–}∞) and the outer layer ({[Hg2Ga4S25/3]2/3–}∞). It exhibits a moderate NLO response and a high laser-induced damage threshold. Theoretical calculations indicate that the HgS4 unit accounts for its much larger NLO response compared to RbCd4Ga3S9. The influence of alkali metals and d10 metals on the initial phase-matching wavelength is also discussed. This work provides inspiration for improving the properties of NLO materials’ properties