Structural Insights into Borates with an Anion‐Templated Open‐Framework Configuration: Asymmetric K₂BaB₁₆O₂₆ versus Centrosymmetric K₃CsB₂₀O₃₂ and Na₂M₂NB₁₈O₃₀ (M=Rb, Cs; N=Ba, Pb)

Abstract

Five new mixed-metal borate crystals, namely, K BaB O , K CsB O , Na Cs BaB O , Na Rb PbB O , and Na Cs PbB O , have been synthesized by the high-temperature solution method. These structures were characterized by single-crystal X-ray diffraction and their B-O configurations are shown to feature complicated three-dimensional (3D) open-framework structures incorporating different types of channels. For all five compounds, the frameworks can be reduced to four-connected (4-c) uninodal nets with sra-, dia- and nbo-type topologies by assigning the [B O ] and [B O ] clusters as basic nodes. First-principles calculations have shown that the multiple cations in mixed-metal borates influence the ground-state electronic structures and associated optical absorptions. In addition, the crystal structures, thermal stabilities, and IR spectra of the title compounds have also been performed.

Ce(IO3)2F2⋅H2O: The First Rare‐Earth‐Metal Iodate Fluoride with Large Second Harmonic Generation Response

“…Iodates have continuously attracted intensive studies due to their plentiful structures and many important applications in fields such as nonlinear optics, luminescence, and photocatalysis –. Owing to the cation having lone‐pair electrons with stereochemical activity (I 5+ ), iodates tend to crystallize in noncentrosymmetric structures and usually show strong second‐order polarizability and large optical anisotropy –. Moreover, iodates have wide transparent wavelength regions (from UV/Vis to mid‐IR) and sizable crystals are easy to grow under mild reaction conditions.…”

Chemical Cosubstitution-Oriented Design of Rare-Earth Borates as Potential Ultraviolet Nonlinear Optical Materials

“…With respect to borates, they reveal a wide optical transparency window, varied acentric structure types, high laser damage thresholds, and large polarizabilities. − As such, several commercial borate-based NLO materials have been developed, including β-BaB 2 O 4 (β-BBO), LiB 3 O 5 (LBO), KBe 2 BO 3 F 2 (KBBF), etc. Among borates, alkali and alkaline earth metals are the preferred alternative elements for designing borate-based NLO materials, mainly because those selected cations are free of d–d or f–f electronic transitions, which is beneficial for good transparency in the UV and even the deep-UV spectral region. , As a result, a variety of mixed alkali and/or alkaline earth metal borates, BaAlBO 3 F 2 , Na 2 CsBe 6 B 5 O 15 , Li 4 Sr­(BO 3 ) 2 , K 3 B 6 O 10 X (X = Br, Cl), , etc., have been frequently reported as front-line candidates for UV or deep-UV NLO materials.…”

Na2SrB16O26: a new borate with independent interpenetrating B–O networks and deep-ultraviolet cutoff edge

“…It is noticed that in the huge number of known borates, structures with independent interpenetrating networks are limited. Typical examples can be found in K 2 BaB 16 O 26 , 60 α-LiKB 8 O 13 37 and Ca 1.13 Zn 0.87 B 8 O 14 , 61 etc .…”