Structure Determination and Relative Properties of Novel Chiral Orthoborate KMgBO3

Chiral and Polar Duality Design of Heteroanionic Compounds: Sr18 Ge9 O5 S31 Based on [Sr3 OGeS3 ]2+ and [Sr3 SGeS3 ]2+ Groups

Chirality and polarity are the two most important and representative symmetry-dependent properties. For polar structures, all the twofold axes perpendicular to the principal axis of symmetry should be removed. For chiral structures, all the mirror-related symmetries and inversion axes should be removed. Especially for duality (polarity and chirality), all of the above symmetries should be broken and that also represents the highest-level challenge. Herein, a new symmetry-breaking strategy that employs heteroanionic groups to construct hourglass-like [Sr3 OGeS3 ]2+ and [Sr3 SGeS3 ]2+ groups to design and synthesize a new oxychalcogenide Sr18 Ge9 O5 S31 with chiral-polar duality is proposed. The presence of two enantiomers of Sr18 Ge9 O5 S31 is confirmed by the single-crystal X-ray diffraction. Its optical activity and ferroelectricity are also studied by solid-state circular dichroism spectroscopy and piezoresponse force microscopy, respectively. Further property measurements show that Sr18 Ge9 O5 S31 possesses excellent nonlinear optical properties, including the strong second harmonic generation efficiency (≈2.5 × AGS), large bandgap (3.61 eV), and wide mid-infrared transparent region (≈15.3 µm). These indicate that the unique microstructure groups of heteroanionic materials are conducive to realizing symmetry-breaking and are able to provide some inspiration for exploring the chiral-polar duality materials.

Development of LiMgBO3:Tb3+ as a new generation material for thermoluminescence based personnel neutron dosimetry

LiMgBO₃:Tb³⁺ TL phosphor was systematically developed having better personnel neutron dosimetry properties as compared with the standard LiF:Mg,Ti dosimeter. Neutron irradiated PL and EPR studies delineated the underlying defect induced TL mechanism.

Two alkali calcium borates exhibiting second harmonic generation and deep-UV cutoff edges

KCa₄B₃O₉ and K_0.59Rb_0.41Ca₄B₃O₉ crystallize in the polar space group with moderate SHG responses. Calculations were performed to elucidate the structure–property relationships.

From LiB3 O5 to NaRbB6 O9 F2 : Fluorine-Directed Evolution of Structural Chemistry

Introducing fluorine into borates indicates the direction for structural evolution. A new fluorooxoborate, NaRbB₆ O₉ F₂ featuring a unique [B₆ O₉ F₂ ]_∞ layered structure and excellent optical properties has been synthesized. It is further demonstrated that incorporation of fluorine can enrich the structural chemistry of borates.

Four alkali metal molybdates with two types of Mo–O chains, ABMo3O10 (A = Li, B = Rb; A = Li, Na, K, B = Cs): synthesis, structure comparison and optical properties

The effects of cation size on the framework structures of four stoichiometrically equivalent alkali metal molybdates were discussed in detail.

ACaBO3(A = Cs, Rb): two new cubic borates with isolated BO3groups

We report new borates, ACaBO₃(A = Cs, Rb) and find out the significant contribution of MO₆octahedra to the formation of cubic structures containing BO₃triangles.

Effect of the cation size on the framework structures of magnesium tungstate, A4Mg(WO4)3 (A = Na, K), R2Mg2(WO4)3 (R = Rb, Cs)

A series of alkali metal magnesium tungstates, A₄Mg(WO₄)₃ (A = Na, K), R₂Mg₂(WO₄)₃ (R = Rb, Cs), were synthesized from a high temperature solution, and their structures were determined by single-crystal X-ray diffraction.

Exploring the influence of cationic skeletons on the arrangement of isolated BO3 groups based on RbMgBO3, CsZn4(BO3)3 and Cs4Mg4(BO3)4

Cationic skeletons formed by cations with strong bonding (Mg²⁺ and Zn²⁺) can influence the arrangement of isolated BO₃ groups, and lower-dimensional cationic skeletons are beneficial to obtain arranged BO₃ groups.

Structure and photoluminescence properties of a rare-earth free red-emitting Mn2+-activated KMgBO3

Abnormal strong absorptions are observed in a Mg-based host KMgBO₃ doped by single Mn²⁺ ions, which lead to a strong red emission band centered at 636 nm.