Designing Sulfide Borate as a Novel Type of Second-Order Nonlinear-Optical Material

Designing second-order nonlinear-optical (NLO) materials with new structures is an attractive topic. Here, a novel type of sulfide borate, Eu2B5O9S, and one of its derivatives combining S2–, I–, and borate anions in one structure (three in one), viz., Eu4.5(B5O9)2SI, are designed and synthesized with a high-temperature solid-state method. They crystallize in the noncentrosymmetric space group Pnn2. As the first sulfide borate being NLO-active, Eu4.5(B5O9)2SI demonstrates good NLO behavior, namely, a moderate powder NLO response of ca. 0.5 times and a high laser-induced damage threshold (LIDT) of ca. 15 times those of AgGaS2, and is phase-matchable. The design strategy and experimental results are verified and explained by density functional theory calculations

Sm₃S₃BO₃: The First Sulfide Borate without S–O and B–S Bonds

An unprecedented quaternary sulfide borate, Sm₃S₃BO₃ (<b>1</b>), was obtained via a high-temperature solid-state synthesis method. It crystallizes in the triclinic space group <i>P</i>1̅, and its 3D structure features a 2D (Sm₂S₂)_∞ wrinkled layer and a 1D (SmS)_∞ ladderlike chain bridged by trigonal-planar (BO₃)^3– through Sm–O bonds, demonstrating the first sulfide borate without S–O and B–S bonds. Its optical energy gap is measured to be around 2.5 eV and verified by electronic structure calculation

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

Closely Related Rare-Earth Metal Germanides <i>RE</i>₂Li₂Ge₃ and <i>RE</i>₃Li₄Ge₄ (<i>RE</i> = La–Nd, Sm): Synthesis, Crystal Chemistry, and Magnetic Properties

Reported are the syntheses, crystal structures, and magnetic susceptibilities of two series of closely related rare-earth metal–lithium germanides <i>RE</i>₂Li₂Ge₃ and <i>RE</i>₃Li₄Ge₄ (<i>RE </i>= La–Nd, Sm). All title compounds have been synthesized by reactions of the corresponding elements at high temperatures, and their structures have been established by single-crystal X-ray diffraction. <i>RE</i>₂Li₂Ge₃ phases crystallize in the orthorhombic space group <i>Cmcm</i> (No. 63) with the Ce₂Li₂Ge₃ structure type, while the <i>RE</i>₃Li₄Ge₄ phases crystallize in the orthorhombic space group <i>Immm</i> (No. 71) with the Zr₃Cu₄Si₄ structure type, respectively. Both of their structures can be recognized as the intergrowths of MgAl₂Cu- and AlB₂-like slabs, and these traits of the crystal chemistry are discussed. Temperature-dependent direct-current magnetization measurements indicate Curie–Weiss paramagnetism in the high-temperature regime for <i>RE</i>₂Li₂Ge₃ and <i>RE</i>₃Li₄Ge₄ (<i>RE </i>= Ce, Pr, Nd), while Sm₂Li₂Ge₃ and Sm₃Li₄Ge₄ exhibit Van Vleck-type paramagnetism. The data are consistent with the local-moment magnetism expected for <i>RE</i>³⁺ ground states. At temperatures below ca. 20 K, magnetic ordering transitions have been observed. The experimental results have been complemented by tight-binding linear muffin-tin orbital electronic-band-structure calculations

Closely Related Rare-Earth Metal Germanides <i>RE</i>₂Li₂Ge₃ and <i>RE</i>₃Li₄Ge₄ (<i>RE</i> = La–Nd, Sm): Synthesis, Crystal Chemistry, and Magnetic Properties

Reported are the syntheses, crystal structures, and magnetic susceptibilities of two series of closely related rare-earth metal–lithium germanides <i>RE</i>₂Li₂Ge₃ and <i>RE</i>₃Li₄Ge₄ (<i>RE </i>= La–Nd, Sm). All title compounds have been synthesized by reactions of the corresponding elements at high temperatures, and their structures have been established by single-crystal X-ray diffraction. <i>RE</i>₂Li₂Ge₃ phases crystallize in the orthorhombic space group <i>Cmcm</i> (No. 63) with the Ce₂Li₂Ge₃ structure type, while the <i>RE</i>₃Li₄Ge₄ phases crystallize in the orthorhombic space group <i>Immm</i> (No. 71) with the Zr₃Cu₄Si₄ structure type, respectively. Both of their structures can be recognized as the intergrowths of MgAl₂Cu- and AlB₂-like slabs, and these traits of the crystal chemistry are discussed. Temperature-dependent direct-current magnetization measurements indicate Curie–Weiss paramagnetism in the high-temperature regime for <i>RE</i>₂Li₂Ge₃ and <i>RE</i>₃Li₄Ge₄ (<i>RE </i>= Ce, Pr, Nd), while Sm₂Li₂Ge₃ and Sm₃Li₄Ge₄ exhibit Van Vleck-type paramagnetism. The data are consistent with the local-moment magnetism expected for <i>RE</i>³⁺ ground states. At temperatures below ca. 20 K, magnetic ordering transitions have been observed. The experimental results have been complemented by tight-binding linear muffin-tin orbital electronic-band-structure calculations

KBiCl₂SO₄: The First Bismuth Chloride Sulfate Being Second-Order Nonlinear Optical Active

A pentanary chloride sulfate KBiCl2SO4 (1) is synthesized via a simple solution routine. 1 is crystallized in the chiral orthorhombic P212121 with Z = 4, and its one-dimensional structure features a {[BiCl2(SO4)]−}∞ chain along the polar axis. Its second-harmonic generation response is approximately 1.7 times that of KDP, and it can achieve phase matchability under the radiation of 1064 nm laser. Its optical energy gap is measured to be 3.95 eV. The density functional theory calculation results indicate that both [BiCl2O3□]5– and [SO4]2– units serve as functional moieties for its promising nonlinear optical performance

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