Regulation of metal valence states for enhancing second harmonic generation performance of chiral tin halides.

Chiral metal halide perovskites (MHPs) possess an inherent noncentrosymmetric structure, offering a promising platform for the development of second-order nonlinear optical (NLO) materials. Recent research has emphasized the influence of metal valence states on the physical and chemical properties of perovskites. In this work, a series of novel chiral tin-based MHPs were constructed by adjusting the metal valence states, thereby tuning the second-order NLO performance.

Optimized Synthesis and Characterization of Janus RhSeCl with Uniform Anionic Valences, Nonlinear Optical and Optoelectronic Properties.

The symmetry-breaking nature of Janus materials enables the design of multifunctional compounds with distinct properties that are inaccessible to traditional materials. However, the limited availability of intrinsically stable Janus materials hinders a complete understanding of their full potential. Here, the first millimeter-sized Janus material, RhSeCl, is successfully synthesized through the precisely controlled chemical vapor transport (CVT) method.

Inverted Chiroptical Properties of Hybrid Metal Halides Through Reversible Chiral Induction Driven by External and Internal Chirality Transfer.

Chiral organic-inorganic hybrid metal halides (OIHMHs) are commonly constructed by introducing pairs of enantiomorphic chiral precursors through a single chirality transfer pathway, which may limit the regulation of chiral structural diversity and chiroptoelectronic properties. Herein, we propose a new strategy for achieving reversible chiral induction of OIHMHs with inverted chiroptical properties through external and internal chirality transfer pathways, by utilizing a single chiral reagent R-/S-α-methylbenzylamine (R-/S-MBA). Specifically, R-MBA can externally induce chiral enrichment of M-DMA(BiInSb)Cl (M-DMA(Bi-In-Sb)Cl, DMA = dimethylammonium cation) without integrating into structure.

Thiophene Sulfone Single Crystal as a Reversible Thermoelastic Linear Actuator with an Extended Stroke and Second-Harmonic Generation Switching.

Dynamic organic crystals are becoming recognized as some of the fastest materials for converting light or heat to mechanical work. The degree of deformation and the response time of any actuating material are often exclusive of each other; however, both factors influence the material's overall performance limits. Unlike polymers, whose disordered structures are not conducive to rapid energy transfer, cooperative phase transitions in dynamic molecular crystals that are amenable to rapid and concerted martensitic-like structure switching could help circumvent that limitation.

Thermoelastic twisting-assisted crystal jumping based on a self-healing molecular crystal.

Adaptive crystals have attracted significant attention from solid-state chemists and crystal engineers for their promising applications in memories, capacitors, sensors, and actuators. Among them, thermosalient crystals are particularly favored thanks to their efficient energy conversions and rapid responses. However, the mechanisms for the mechanical responses of thermosalient crystals remain largely unclear.

Extendable Synthesis of Organic Cations for In Situ Construction of Hybrid Metal Halides with Near-Unity Photoluminescence and Strong Second Harmonic Generation.

The A-site organic components of organic-inorganic hybrid metal halides (OIHMHs) significantly impact their crystal structure and optoelectronic properties. However, chemical modification of A-site cations has been mostly limited to commercial organic precursors, which restricts the structural variability of OIHMHs for optimal functionalities. Herein we have proposed an extendable synthesis approach to the direct procurability of various organic cations with desireable structures for the in situ construction of a library of OIHMH materials.

Mechanical Twisting-Induced Enhancement of Second-Order Optical Nonlinearity in a Flexible Molecular Crystal.

Flexible molecular crystals are essential for advancing smart materials, providing unique functionality and adaptability for applications in next-generation electronics, pharmaceuticals, and energy storage. However, the optical applications of flexible molecular crystals have been largely restricted to linear optics, with nonlinear optical (NLO) properties rarely explored. Herein, we report on the application of mechanical twisting of flexible molecular crystals for second-order nonlinear optics.

Supramolecular Assembly Enhanced Linear and Nonlinear Chiroptical Properties of Chiral Manganese Halides.

Chiral hybrid organic-inorganic metal halides (HOMHs) hold great promise in broad applications ranging from ferroelectrics, spintronics to nonlinear optics, owing to their broken inversion symmetry and tunable chiroptoelectronic properties. Typically, chiral HOMHs are constructed by chiral organic cations and metal anion polyhedra, with the latter regarded as optoelectronic active units. However, the primary design approaches are largely constrained to regulation of general components within structural formula.

Macroscopic Twisting of Chiral Metal Halide Single Crystals Driven by Thermo-Induced Topochemical Dehydration.

Dynamic twisting crystals, combining the features of dynamic crystals and twisting crystals, promise advanced applications in targeted drug delivery, biosensors, microrobots, and spiral optoelectronics. However, the determination of dynamic twisting crystals with specific directions remains a formidable challenge in practical applications. Herein, based on organic-inorganic hybrid metal halide (OIHMH) single crystals, we have realized the chirality-induced macroscopic twisting of single crystals driven by a thermo-induced topochemical dehydration reaction.

Circularly polarized luminescence and nonlinear optical harmonic generation based on chiral zinc halides.

Chiral hybrid metal halides have grabbed extensive attention in linear and nonlinear chiroptics. Herein, 0D chiral zinc halides, (-/-2-MP)ZnCl, have been fabricated, which demonstrate high efficiency second-order nonlinear optical responses. Incorporating Sb into the chiral zinc halide matrix triggers the circularly polarized luminescence effectively with a balance between quantum yield and luminescence dissymmetry factor.

Linear optical afterglow and nonlinear optical harmonic generation from chiral tin(IV) halides: the role of lattice distortions.

The striking chemical variability of hybrid organic-inorganic metal halides (HOMHs) endows them with fascinating optoelectronic properties. The inorganic skeletons of HOMHs are often flexible and their lattice deformations could serve as an effective factor for enabling the functionalities of HOMHs. Here, the linear and nonlinear optical properties of zero-dimensional (0D) tin(IV) halides have been tuned by structural distortion facilitated by the chiral amines.

Prediction of highly stable two-dimensional materials of boron and phosphorus: structural and electronic properties.

The discovery of two-dimensional (2D) semiconducting materials has attracted broad research interest, owing to their wide applications in spintronics and optoelectronics. Group III-V 2D materials such as hexagonal boron nitride (h-BN) have been demonstrated with remarkable electronic properties. However, the 2D materials consisting of boron and phosphorus have not been comprehensively explored.

Induction of Chiral Hybrid Metal Halides from Achiral Building Blocks.

Chiral hybrid organic-inorganic metal halides (HOMHs) with intrinsic noncentrosymmetry have shown great promise for broad applications in chiroptoelectronics, spintronics, and ferroelectronics. However, the construction strategies for chiral HOMHs often involve chiral building blocks in their frameworks, which greatly limit their chemical diversity. Here, we take advantage of a chiral induction approach and have successfully constructed a series of chiral HOMHs, (DMA = dimethylammonium, M = Sb or Bi, X = Cl or Br), based on achiral precursors.

0D chiral hybrid indium(III) halides for second harmonic generation.

Chiral metal halides have shown great potential for application in next generation nonlinear optical (NLO) devices owing to their intrinsic non-centrosymmetry. However, the structures and properties of chiral hybrid indium halides have been rarely reported, especially when it comes to second-harmonic generation (SHG) in NLO. In this work, we have synthesized a pair of new zero-dimensional (0D) chiral hybrid indium halides, (-MPEA)InCl and (-MPEA)InCl, and studied their NLO properties.

Methylpiperazine based 0D chiral hybrid lead halides for second harmonic generation.

Hybrid organic-inorganic metal halides (HOMHs) have recently attracted broad research interest for their structural tunability and remarkable optoelectronic properties. Among them, chiral HOMHs have demonstrated promising applications in second-order nonlinear optics (NLO) on account of their inherent noncentrosymmetric structures. Herein, we synthesized two new chiral HOMHs, (-/-2-CHN)PbI, based on -/-2-methylpiperazine chiral amines.

Chiral Hybrid Copper(I) Halides for High Efficiency Second Harmonic Generation with a Broadband Transparency Window.

Chiral hybrid organic-inorganic metal halides (HOMHs) with intrinsic noncentrosymmetry have shown great promise for applications in second-order nonlinear optics (NLO). However, established chiral HOMHs often suffer from their relatively small band gaps, which lead to negative impacts on transparent window and laser-induced damage thresholds (LDT). Here, we have synthesized two chiral HOMHs based on Cu halides, namely (R-/S-MBA)CuBr , which feature well-balanced NLO performances with a highly efficient SHG response, outstanding optical transparency, and high LDT.