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Dong-Wei Fu, Ai-Chun Liu Department of Hematology, Harbin Medical University Cancer Hospital, Harbin, Heilongjiang 150081, People’s Republic of ChinaCorrespondence: Ai-Chun LiuDepartment of Hematology, Harbin Medical University, Cancer Hospital, Harbin, Heilongjiang 150081, People’s Republic of ChinaEmail liuaichun93@163.comPurpose: Currently, there is no efficient and feasible method for diffuse large B-cell lymphoma (DLBCL) in clinical practice, and the main reason is the unclear pathogenesis of DLBCL, which leads to a high fatality rate of DLBCL.Methods: Therefore, it is meaningful to explore the molecular mechanism of DLBCL and find a targeted therapeutic approach from the molecular level.Results: Long non-coding RNA (lncRNA) SBF2-AS1 was highly expressed in DLBCL tissues and cell lines. Silencing of SBF2-AS1 inhibited the viability and growth of OCI-LY-3 cells. Furthermore, SBF2-AS1 acted as a sponge of miR-494-3p and inhibited its expression. And miR-494-3p directly targeted FGFR2. Functionally, forced expression of miR-494-3p or knockdown of FGFR2 removed the promoted effects of lncRNA SBF2-AS1 on DLBCL development. In vivo tumorigenesis experiments indicated SBF2-AS1 accelerated tumor growth via miR-494-3p/FGFR2 axis.Conclusion: Our study revealed that SBF2-AS1 promoted the growth of DLBCL, which were mediated by miR-494-3p/FGFR2 axis.Keywords: diffuse large B-cell lymphoma, SBF2-AS1, miR-494-3p, FGFR2, tumorigenesis

The lone pair electrons in the electronic structure of molecules have been a prominent research focus in chemistry for more than a century. Stable s 2 lone pair electrons significantly influence material properties, including thermoelectric properties, nonlinear optical properties, ferroelectricity, and electro(photo)catalysis. While major advances have been achieved in understanding the influence of lone pair electrons on material characteristics, research on this effect in organic-inorganic hybrid materials is in its initial stage. In this work, we successfully obtained a novel organic-inorganic hybrid multifunctional material incorporating Ge with 4s 2 lone pair electrons, (MeHDabco) 2 [GeBr 3 ] 4 -H 2 O (MeHDabco=N-methyl-1,4-diazabicyclo[2.2.2]octane) (1). Driven by the stereochemically active lone pair electrons on the Ge 2+ , 1 crystallizes in the noncentrosymmetric space group P2 1 at room temperature and exhibits good second harmonic generation (SHG) responses. Interestingly, 1 also shows electrocatalytic activity for the hydrogen evolution reaction (HER) due to the existence of lone pair electrons on Ge 2+ cations. The electrochemical experiment combined with the density functional theory (DFT) calculations revealed that the lone pair electrons act as both an active site for proton adsorption and facilitate the ionization of water. This work not only emphasizes the important role of lone pair electrons in material properties and functions but also provides new insight for designing novel Ge-based multifunctional hybrid materials., (© 2024 Wiley-VCH GmbH.)

Ferroelectricity in metal-free perovskites (MFPs) has emerged as an academic hotspot for their lightweight, eco-friendly processability, flexibility, and degradability, with considerable progress including large spontaneous polarization, high Curie temperature, large piezoelectric response, and tailoring coercive field. However, their equivalent polarization axes as a key indicator are far from enough, although multiaxial ferroelectrics are highly preferred for performance output and application flexibility that profit from as many equivalent polarization directions as possible with easier reorientation. Here, by implementing the synergistic overlap of regulating anionic geometries (from spherical I - to octahedral [PF 6 ] - and to tetrahedral [ClO 4 ] - or [BF 4 ] - ) and cationic asymmetric modification, we successfully designed multiaxial MFP ferroelectrics CMDABCO-NH 4 -X 3 (CMDABCO = N -chloromethyl- N '-diazabicyclo[2.2.2]octonium; X = [ClO 4 ] - or [BF 4 ] - ) with the lowest P 1 symmetry. More impressively, systemic characterizations indicate that they possess 24 equivalent polarization axes (Aizu notations of 432F1 and m 3̅ m F1, respectively)─the maximum number achievable for ferroelectrics. Benefiting from the multiaxial feature, CMDABCO-NH 4 -[ClO 4 ] 3 has been demonstrated to have excellent piezoelectric sensing performance in its polycrystalline sample and prepared composite device. Our study provides a feasible strategy for designing multiaxial MFP ferroelectrics and highlights their great promise for use in microelectromechanical, sensing, and body-compatible devices.

Molecular ferroelectrics have made breakthrough progress in intrinsic piezoelectric response that can be on par with advanced inorganic piezoelectric ceramics. However, their successful applications in high-density energy harvesting and self-powered flexible devices have been great challenge, owing to the low elastic moduli, intrinsically brittle, and fracture proneness of such material systems under mechanical loading. Here, we have developed a flexible porous composite piezoelectric material by using soft thermoplastic polyurethane (TPU) and molecular ferroelectric materials. Benefiting from the porous structure of TPU, the flexible piezoelectric composites enable effectively large doping ratio (50%) of [Me 3 NCH 2 Cl]CdCl 3 (TMCM-CdCl 3 ) and highly efficient stress absorption, coupled with the excellent piezoelectric properties of TMCM-CdCl 3 , to realize a superior power density (636.9 µW cm -2 or 1273.9 µW cm -3 ). This output is 2000 times higher than that of flexible piezoelectric materials represented by poly(vinylidene fluoride) (PVDF). We believe that the outstanding performance of the porous composite piezoelectric material would pave a feasible way for real industrial applications of molecular ferroelectrics., (© 2024. The Author(s).)

Hybrid organic-inorganic perovskite (HOIP) ferroelectrics exhibit polarization reversibility and have a wide range of applications in the fields of smart switches, memorizers, sensors, etc. However, the inherent limitations of small spontaneous polarization ( P s ) and large coercive field ( E c ) in ferroelectrics have impeded their broader utilization in electronics and data storage. Molecular ferroelectrics, as a powerful supplement to inorganic ferroelectrics, have shown great potential in the new generation of flexible wearable electronic devices. The important research responsibility is to greatly improve progressiveness and overcome the above limitations. Here, a novel one-dimensional (1D) HOIP ferroelectric, (3-F-BTAB)PbBr 3 (3-F-BTAB = 3-fluorobenzyltrimethylammonium), was successfully synthesized by employing the H/F substitution strategy to modify parent compound (BTAB)PbBr 3 (BTAB = benzyltrimethylammonium), which undergoes a ferroelectric phase transition with Aizu notation 2/ m F2 at 420 K. Notably, (3-F-BTAB)PbBr 3 demonstrates exceptional ferroelectric properties with a large P s of 7.18 μC cm -2 and a low E c of 1.78 kV cm -1 . As far as we know, (3-F-BTAB)PbBr 3 features the largest P s among those reported for 1D lead-based HOIP ferroelectrics. This work enriches the 1D lead-based ferroelectric family and provides guidance for applying ferroelectrics in low-voltage polar memories., Competing Interests: The authors declare no conflict of interest., (This journal is © The Royal Society of Chemistry.)

Three-dimensional (3D) pseudohalide rare-earth double perovskites (PREDPs) have garnered significant attention for their versatile physical properties, including ferroelectricity, ferroelasticity, large piezoelectric responses, and circularly polarized luminescence. However, their potential for X-ray detection remains unexplored, and the low Curie temperature (T C ) limits the performance window for PREDP ferroelectrics. Here, by applying the chemical regulation strategies involving halogen substitution on the organic cation and Rb/Cs substitution to the PREDP [(R)-M3HQ] 2 RbEu(NO 3 ) 6 [(R)-M3HQ=(R)-N-methyl-3-hydroxylquinuclidinium] with a low T C of 285 K, a novel 3D PREDP ferroelectric [(R)-CM3HQ] 2 CsEu(NO 3 ) 6 [(R)-CM3HQ=(R)-N-chloromethyl-3-hydroxylquinuclidinium] are successfully synthesized, for which the T C reaches 344 K. More importantly, such a strategy endowed [(R)-CM3HQ] 2 CsEu(NO 3 ) 6 with notable X-ray detection capabilities. Centimeter-sized [(R)-CM3HQ] 2 CsEu(NO 3 ) 6 single crystals fabricated from aqueous solutions demonstrated a sensitivity of 1307 μC Gy air -1  cm -2 and a low detectable dose rate of 152 nGy air  s -1 , the highest sensitivity reported for hybrid double perovskite ferroelectric detectors. This work positions PREDPs as promising candidates for the next generation of eco-friendly optoelectronic materials and also offers substantial insights into the interaction between structure, composition, and functionality in ferroelectric materials., (© 2024 Wiley-VCH GmbH.)

This study presents a novel approach using polyol-based proliposome to produce marine phospholipids nanoliposomes. Proliposomes were formulated by blending glycerol with phospholipids across varying mass ratios (2:1 to 1:10) at room temperature. Analysis employing polarized light microscopy, FTIR, and DSC revealed that glycerol disrupted the stacked acyl groups within phospholipids, lowering the phase transition temperature (T m ). Krill oil phospholipids (KOP) proliposomes exhibited superior performance in nanoliposomes formation, with a mean diameter of 125.60 ± 3.97 nm, attributed to the decreased T m (-7.64 and 7.00 °C) compared to soybean phospholipids, along with a correspondingly higher absolute zeta potential (-39.77 ± 1.18 mV). The resulting KOP proliposomes demonstrated liposomes formation stability over six months and under various environmental stresses (dilution, thermal, ionic strength, pH), coupled with in vitro absorption exceeding 90 %. This investigation elucidates the mechanism behind glycerol-formulated proliposomes and proposes innovative strategies for scalable, solvent-free nanoliposome production with implications for functional foods and pharmaceutical applications., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Since the concept of "multiferroic" was first proposed in 1968, the coupling effect between different ferroic orders has attracted great interest in energy, information, and biomedical fields. However, the fully ferroelectric-fully ferroelastic effect has never been experimentally observed in hybrid perovskites, even though this effect was predicted to exist half a century ago. Realizing such cross-linking effects of polarization vectors and strain tensors has always been a huge challenge because of the complex difference in these two ferroic origins. Here, we report a multiferroic with full ferroelectricity and full ferroelasticity in two-dimensional (2D) hybrid perovskites based on ferroelectrochemistry. The dynamic molecular reorientations endow (cyclohexanemethylaminium) 2 PbCl 4 with a desired symmetry change of 4̅2 m F mm 2 at a Curie temperature of 411.8 K. More strikingly, the switchable evolution of ferroelastic domains was directly observed under the control of either electric or mechanical fields, which is the first experimental observation of a fully ferroelectric-fully ferroelastic effect in hybrid perovskites. This work would provide new insights into understanding the intrinsic cross-linking mechanism between ferroelectricity and ferroelasticity toward the development of multichannel interactive microelectronic devices.

Luminescent ferroelectrics are holding exciting prospect for integrated photoelectronic devices due to potential light-polarization interactions at electron scale. Integrating ferroelectricity and long-lived afterglow emission in a single material would offer new possibilities for fundamental research and applications, however, related reports have been a blank to date. For the first time, we here achieved the combination of notable ferroelectricity and afterglow emission in an organic-inorganic hybrid material. Remarkably, the presented (4-methylpiperidium)CdCl 3 also shows noticeable antiferroelectric behavior. The implementation of cationic customization and halogen engineering not only enables a dramatic enhancement of Curie temperature of 114.4 K but also brings a record longest emission lifetime up to 117.11 ms under ambient conditions, realizing a leapfrog improvement of at least two orders of magnitude compared to reported hybrid ferroelectrics so far. This finding would herald the emergence of novel application potential, such as multi-level density data storage or multifunctional sensors, towards the future integrated optoelectronic devices with multitasking capabilities., (© 2024 Wiley‐VCH GmbH.)

Hybrid organic-inorganic perovskite (HOIP) ferroelectric materials have great potential for developing self-powered electronic transducers owing to their impressive piezoelectric performance, structural tunability and low processing temperatures. Nevertheless, their inherent brittle and low elastic moduli limit their application in electromechanical conversion. Integration of HOIP ferroelectrics and soft polymers is a promising solution. In this work, a hybrid organic-inorganic rare-earth double perovskite ferroelectric, [RM3HQ] 2 RbPr(NO 3 ) 6 (RM 3 HQ = (R)-N-methyl-3-hydroxylquinuclidinium) is presented, which possesses multiaxial nature, ferroelasticity and satisfactory piezoelectric properties, including piezoelectric charge coefficient (d 33 ) of 102.3 pC N -1 and piezoelectric voltage coefficient (g 33 ) of 680 × 10 -3  V m N -1 . The piezoelectric generators (PEG) based on composite films of [RM3HQ] 2 RbPr(NO 3 ) 6 @polyurethane (PU) can generate an open-circuit voltage (V oc ) of 30 V and short-circuit current (I sc ) of 18 µA, representing one of the state-of-the-art PEGs to date. This work has promoted the exploration of new HOIP ferroelectrics and their development of applications in electromechanical conversion devices., (© 2023 Wiley‐VCH GmbH.)

Pickering high internal phase emulsions (HIPEs) have gained significant attention for various applications within the food industry. Yeast cell protein (YCP), derived from spent brewer's yeast, stands out as a preferred stabilizing agent due to its cost-effectiveness, abundance, and safety profile. However, challenges persist in utilizing YCP, notably its instability under high salt concentration, thermal processing, and proximity to its isoelectric point. This study aimed to enhance YCP's emulsifying properties through glycation with glucose and evaluate its efficacy as a stabilizer for curcumin (CUR)-loaded HIPEs. The results revealed that glycation increased YCP's surface hydrophobicity, exposing hydrophobic groups. This augmentation, along with steric hindrance from grafted glucose molecules, improved emulsifying properties, resulting in a thicker interfacial layer around oil droplets. This fortified interfacial layer, in synergy with steric hindrance, bolstered resistance to pH changes, salt ions, and thermal degradation. Moreover, HIPEs stabilized with glycated YCP exhibited reduced oxidation rates and improved CUR protection. In vitro digestion studies demonstrated enhanced CUR bioaccessibility, attributed to a faster release of fatty acids. This study underscores the efficacy of glycation as a strategic approach to augment the applicability of biomass proteins, exemplified by glycated YCP, in formulating stable and functional HIPEs for diverse food applications., Competing Interests: Declaration of competing interest The authors declare no known competing financial interests or personal relationships that could have influenced the work reported in this paper., (Copyright © 2023 Elsevier B.V. All rights reserved.)

The ability to generate and manipulate photoluminescence (PL) behavior has been of primary importance for applications in information security. Excavating novel optical effects to create more possibilities for information encoding has become a continuous challenge. Herein, we present an unprecedented PL temporary quenching that highly couples with thermodynamic phase transition in a hybrid crystal (DMML) 2 MnBr 4 (DMML=N,N-dimethylmorpholinium). Such unusual PL behavior originates from the anomalous variation of [MnBr 4 ] 2- tetrahedrons that leads to non-radiation recombination near the phase transition temperature of 340 K. Remarkably, the suitable detectable temperature, narrow response window, high sensitivity, and good cyclability of this PL temporary quenching will endow encryption applications with high concealment, operational flexibility, durability, and commercial popularization. Profited from these attributes, a fire-new optical encryption model is devised to demonstrate high confidential information security. This unprecedented optical effect would provide new insights and paradigms for the development of luminescent materials to enlighten future information encryption., (© 2023 Wiley-VCH GmbH.)

Organic-inorganic hybrid lead halide perovskites (OLHPs), represented by (CH 3 NH 3 )PbI 3 , are one of the research focus due to their exceptional performance in optoelectronic applications, and ferroelastic domain walls are benign to their charge carrier transport that is confirmed recently. Among them, the 1D OLHPs feature better stability against desorption and moisture, but related 1D ones possessing ferroelasticity are rarely investigated and reported so far. In this work, the 1D ferroelastic semiconductor (N-iodomethyl-N-methyl-morpholinium)PbI 3 ((IDMML)PbI 3 ) is prepared successfully by introducing successively halogenate atoms from Cl, Br to I into the organic cation of the prototype (N,N-dimethylmorpholinium)PbI 3 ((DMML)PbI 3 ). Notably, (IDMML)PbI 3 shows the narrow bandgap energy (≈2.34 eV) according to the ultraviolet-visible absorption spectrum and the theoretical calculation, and possesses the evident photoconductive characteristic with the on/off ratio of current of ≈50 under the 405 nm light irradiation. This work provides a new case for the ferroelastic OLHPs and will inspire intriguing research in the field of optoelectronic., (© 2023 Wiley-VCH GmbH.)

High internal phase emulsions (HIPEs) have emerged as a promising structured oil system in food industry. This study developed self-emulsifying HIPEs (SHIPEs) using Antarctic krill oil (KO) with endogenous phospholipids as surfactant and algae oil as a diluent. The influence of phospholipids self-assembly on SHIPEs formation was investigated by evaluating the microstructures, particle size, rheological properties, and water distribution. Results demonstrated that the concentration and self-assembly behavior of phospholipids dominated the SHIPEs formation. Optimized SHIPEs with desirable gel properties contained 10 wt% krill oil in the oil phase at an 80 wt% oil phase level. Furthermore, these SHIPEs exhibited excellent performance in 3D printing applications. Hydrated phospholipids formed lamellar network at the oil-water interface, enhancing gel strength by crosslinking oil droplets. These findings shed light on the self-assembly of phospholipids during HIPEs formation and highlight the potential phospholipids-rich marine lipids in SHIPEs for functional food products development., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

Organic-inorganic hybrid perovskites (OIHPs) with dielectric switching functions have aroused comprehensive scientific interest, benefitting from their promising applications in sensors and information storage. However, to date, most of these materials discovered thus far possess a single function and are limited in their applicability, failing to meet the requirements of diverse applications. Moreover, the discovery of these materials has been largely serendipitous. Building multifunctional OIHPs with dielectric switching and semiconductors remains a daunting task. In this context, by introducing [C 7 H 16 N] + as cations and in combination with lead halide with semiconducting properties, two OIHPs [C 7 H 16 N]PbI 3 (1) and [C 7 H 16 N]PbBr 3 (2) ([C 7 H 16 N] + = (cyclopropylmethyl) trimethylammonium) have been successfully designed. They have dielectric switching properties close to 253 and 279 K and semiconducting behavior with band gaps of 2.67 and 3.22 eV. The phase transition temperature increased by 26 K through halogen substitution. In summary, our findings in this study provide insights into the application of the halogen substitution regulation strategy and open up new possibilities for designing perovskite semiconductors with dielectric switching functionality.

As an innovative form of stimulus-response materials, organic-inorganic hybrid phase transition materials have become a wonderful contender in the field of functional electronic equipment due to their versatile structure, intensive functions and straightforward preparation. However, the targeted regulation and optimization of the electrical/optical response, along with the establishment of regular structure-performance relationships, pose significant challenges in meeting the diverse demands of practical applications over an extended period. Herein, we conducted a systematic investigation into the role of lattice void occupancy in regulating phase transition temperature ( T p ) and related optical/electrical bistability. By taking hybrid material [TMEA][Cd(SCN) 3 ] featuring a flexible ammonium cation [TMEA] + (TMEA = ethyltrimethylammonium) as the prototype, we successfully synthesized three phase transition materials, namely [DEDMA][Cd(SCN) 3 ], [TEMA][Cd(SCN) 3 ] and [TEA][Cd(SCN) 3 ] (DEDMA = diethyldimethylammonium, TEMA = triethylmethylammonium, and TEA = tetraethylammonium), and the excellent regulation of the physical properties of these compounds was achieved through subtle engineering of void occupancy. More strikingly, [TEA][Cd(SCN) 3 ] exhibits remarkable bistable properties in terms of dielectric and nonlinear optical responses (with second-harmonic generation intensity reaching 2.5 times that of KDP). This work provides a feasible avenue to reasonably customise organic-inorganic hybrid phase transition materials and finely adjust their intriguing functionalities., Competing Interests: The authors declare no conflict of interest., (This journal is © The Royal Society of Chemistry.)

Construction of ferroelectric and optimization of macroscopic polarization has attracted tremendous attention for next generation light weight and flexible devices, which brings fundamental vitality for molecular ferroelectrics. However, effective molecular tailoring toward cations makes ferroelectric synthesis and modification relatively elaborate. Here, the study proposes a facile method to realize triggering and optimization of ferroelectricity. The experimental and theoretical investigation reveals that orientation and alignment of polar cations, dominated factors in molecular ferroelectrics, can be controlled by easily processed anionic modification. In one respect, ferroelectricity is induced by strengthened intermolecular interaction. Moreover, ≈50% of microscopic polarization enhancement (from 8.07 to 11.68 µC cm -2 ) and doubling of equivalent polarization direction (from 4 to 8) are realized in resultant ferroelectric FEtQ2ZnBrI 3 (FEQZBI, FEtQ = N-fluoroethyl-quinuclidine). The work offers a totally novel platform for control of ferroelectricity in organic-inorganic hybrid ferroelectrics and a deep insight of structure-property correlations., (© 2023 Wiley-VCH GmbH.)

The multifunctional tuning of solid-state dielectric switches constructed from organic-inorganic hybrid materials (OIHMs) has received great attention. In particular, molecular ferroelastics with dielectric phase transitions have considerable potential in the optical and electrical fields owing to their adjustable structures and physical features. However, it remains a challenge to effectively design ferroelastics with high phase transition temperature ( T c ). We used [TTMA] 2 CdI 4 (TTMA = tetramethylammonium, 1) as a template to continuously increase the molecular weight and change the structure of the hybrid material by modifying and extending the alkane chain in the cation. Therefore, a series of OIHMs were eventually developed: [TMEA] 2 CdI 4 (TMEA = trimethylethylammonium, 2), [TMPA] 2 CdI 4 (TMPA = trimethylpropylammonium, 3), and [TMIPA] 2 CdI 4 (TMIPA = trimethyliso-propylammonium, 4). Among them, the T c of ferroelastic 3 increased up to 387 K. DSC and temperature-related dielectric constant tests prove the occurrence of the phase transition for 1, 2, and 3. The structures further indicate that the phase transition is caused by the order-disorder cation motion. The extension of the alkyl chain greatly increases T c and endows 3 with ferroelasticity at room temperature.

Switchable materials have attracted enormous interest due to their promising applications in important fields such as sensing, electronic components, and information storage. Nevertheless, obtaining multifunctional switching materials is still a problem worth investigating. Herein, by incorporating ( Rac -, L -, D -2-amino-1-propanol) as the templating cation, we have obtained ( Rac -, L -, D -HTMPA)CdCl 3 (HTMPA = 1-hydroxy- N , N , N -trimethyl-2-propanaminium). We have adopted a chiral chemistry strategy that causes ( Rac -HTMPA)CdCl 3 in the central symmetric space to crystallize in the chiral space group. Based on the modulation of the homochiral strategy, ( L- , D- HTMPA)CdCl 3 shows a dual phasic transition at 269 and 326 K and a switchable second-harmonic generation response. In addition, ( L -, D -HTMPA)CdCl 3 is chiral switchable material to exhibit stable dual dielectric and second-harmonic generation (SHG) switches. This work provides an approach to exploring multifunctional chiral switchable materials.

Abundant chemical diversity and structural tunability make organic-inorganic hybrid perovskites (OIHPs) a rich ore for ferroelectrics. However, compared with their inorganic counterparts such as BaTiO 3 , their ferroelectric key properties, including large spontaneous polarization (P s ), low coercive field (E c ), and strong second harmonic generation (SHG) response, have long been great challenges, which hinder their commercial applications. Here, a quasi-one-dimensional OIHP DMAGeI 3 (DMA = Dimethylamine) is reported, with notable ferroelectric attributes at room temperature: a large P s of 24.14 μC/cm 2 (on a par with BaTiO 3 ), a low E c below 2.2 kV/cm, and the strongest SHG intensity in OIHP family (about 12 times of KH 2 PO 4 (KDP)). Revealed by the first-principles calculations, its large P s originates from the synergistic effects of the stereochemically active 4s 2 lone pair of Ge 2+ and the ordering of organic cations, and its low kinetic energy barrier of small DMA cations results in a low E c . Our work brings the comprehensive ferroelectric performances of OIHPs to a comparable level with commercial inorganic ferroelectric perovskites., (© 2023. The Author(s).)

Hybrid lead halide perovskites have received extensive scientific attention owing to their great potential in the field of fluorescent displays and light-emitting diodes. Currently, most luminescent materials contain functional molecular and rare-earth metal ion parts. However, the mechanism of photoluminescence property in two-dimensional hybrid lead halide perovskites with different layered inorganic skeletons has been reported rarely. To better understand the effect of an inorganic skeleton on the fluorescence property, here, we report three organic-inorganic hybrid materials with different layered inorganic frameworks: (MACH) 2 ·PbBr 4 (Prv-1, MACH = cyclohexylmethylammonium), (2-MPQ)·PbBr 4 (Prv-2, 2-MPQ = 2-methylpiperazinium), and (TMBA) 4 ·Pb 3 Br 10 (Prv-3, TMBA = N ' N ' N '-trimethylbenzylammonium). Among them, Prv-1 is a (100)-oriented perovskite, Prv-2 belongs to the (110)-oriented perovskite, and the inorganic framework of Prv-3 possesses [Pb 3 Br 10 ] units. Interestingly, Prv-1 has a strong blue-violet fluorescence emission, while the luminescence effect of Prv-2 is very weak; notably, Prv-3 emits a charming bright-orange light. Meanwhile, results of theoretical computational studies also reveal that the electronic structure of all three compounds is highly dependent on structurally distorted [PbBr 6 ] octahedra, and the frontier molecular orbital (FMO) analysis further suggests that HOMO and LUMO of Prv-3 are contributed by inorganic and organic components, respectively. In addition, all three materials belong to direct band gap semiconductors, and the band gaps are 2.79, 2.97, and 2.76 eV, respectively. Significantly, there are obvious differences in conduction bands. Based on the above analysis, the photoluminescence mechanism of three hybrid materials is explained from the electronic levels. Consequentially, this work might provide practical strategies and perspectives for exploring novel structure-related properties.

A new ferroelastic organic salt nicotinic acid bromide (N-Br) was connected by hydrogen bonding with nicotinic acid cations via a halogen substitution strategy. It exhibits a ferroelastic phase transition from P 2 1 / m to P 1̄ with 2/ mF 1̄ Aizu notation with a high Curie temperature ( T c ) of 402 K. Moreover, optical regulation from blue light to white light was achieved by halogen substitution.

Background: The application of curcumin (CUR) in the food industry is limited by its instability, hydrophobicity and low bioavailability. Yeast cell protein (YCP) is a by-product of spent brewer's yeast, which has the potential to deliver bioactive substances. However, the environmental stresses such as pH, salt and heat treatment has restricted its application in the food industry. Maillard reaction as a non-enzymatic browning reaction can improve protein stability under environmental stress., Results: The CUR was successfully encapsulated into the hydrophobic core of YCP/glycated YCP (GYCP) and enhanced by hydrogen bonding, resulting in static fluorescence quenching of YCP/GYCP. The average diameter and dispersibility of GYPC-CUR nanocomplex were significantly improved after glucose glycation (121.40 nm versus 139.70 nm). Moreover, the encapsulation capacity of CUR was not influenced by glucose glycation. The oxidative stability and bioaccessibility of CUR in nanocomplexes were increased compared with free CUR, especially complexed with GYCP conjugates., Conclusion: Steric hindrance provided by glucose conjugation improved the enviriomental stability, oxidative activity and bioaccessibility of CUR in nanocomplexes. Thus, glucose-glycated YCP has potential application as a delivery carrier for hydrophobic compounds in functional foods. © 2022 Society of Chemical Industry., (© 2022 Society of Chemical Industry.)

Compared with uniaxial molecular ferroelectrics, multiaxial ferroelectrics have better application prospects because they are no longer subject to the single-crystal form and have been pursued in recent years. Halogen engineering refers to the adjustment of halogens in materials at the atomic level, which can not only explore multiaxial ferroelectrics but also help to improve piezoelectrics, recently. In this work, we successfully synthesized and characterized three multiaxial plastic ferroelectrics through the precise molecular design from I to Cl, confirming the increase of the number of polar axes of ferroelectrics from 3 to 6, the increase of second-harmonic generation density from 2.1 times to nearly 6 times of monopotassium phosphate, and the increase of piezoelectric coefficient by 140%. This systematic work has proved that halogen engineering can not only enrich the family of multiaxial plastic ferroelectrics but also promote the further development of nonlinear optical and piezoelectric materials.

In order to meet the needs of social development, increasing research attention has been paid to multifunctional molecular-based phase-transition materials. The traditional phase-transition materials with a single functional property can be transformed into magnificent ones by adding additional functional properties-for instance photoluminescence and magnetic order- because having two or more functional properties simultaneously greatly broadens the fields of their applications. At present, there are very few multifunctional phase-transition materials showing excellent performance, and the crystal structure design and performance optimization of materials still need to be studied in depth. Herein, we report the development of two organic-inorganic hybrid materials: (MBA) 2 ZnI 4 (1, MBA = 4-methoxybenzylammonium) with switchable dielectricity and a high phase-transition temperature ( T c = 359.55 K), and (MBA) 2 ZnBr 4 (2) with green luminescence ( λ exc = 314 nm) and nonlinear optical properties (0.75× KDP). A two-dimensional (2D) fingerprint analysis of the Hirshfeld surface plots revealed a significant difference between the hydrogen-bonding interaction before the phase transition and that afterwards. The two compounds were further verified, from energy band structure calculations, to be direct-band-gap semiconductors. In conclusion, this work has provided a viable strategy, involving the application of chemical modifications, for designing various functional materials.

Organic-inorganic halide perovskites (OIHPs) are very eye-catching due to their chemical tunability and rich physical properties such as ferroelectricity, magnetism, photovoltaic properties and photoluminescence. However, no nickel-based OIHP ferroelectrics have been reported so far. Here, we designed an ABX 3 OIHP ferroelectric (3-pyrrolinium)NiCl 3 , where the 3-pyrrolinium cations are located on the voids surrounded by one-dimensional chains composed of NiCl 6 -face-sharing octahedra via hydrogen bonding interactions. Such a unique structure enables the (3-pyrrolinium)NiCl 3 with a high spontaneous polarization ( P s ) of 5.8 μC cm -2 and a high Curie temperature ( T c ) of 428 K, realizing dramatic enhancement of 112 and 52 K compared to its isostructural (3-pyrrolinium)MCl 3 (M = Cd, Mn). To our knowledge, remarkably, (3-pyrrolinium)NiCl 3 should be the first case of nickel(ii)-based OIHP ferroelectric to date, and its T c of 428 K (35 K above that of BaTiO 3 ) is the highest among all reported one-dimensional OIHP ferroelectrics. This work offers a new structural building block for enriching the family of OIHP structures and will inspire the further exploration of new nickel(ii)-based OIHP ferroelectrics., Competing Interests: The authors declare no conflict of interest., (This journal is © The Royal Society of Chemistry.)

Organic-inorganic Hybrid (OIH) materials for multifunctional switchable applications have attracted enormous attention in recent years due to their excellent optoelectronic properties and good structural tunability. However, it still remains challenging to fabricate one simple OIH compound with multi-functionals properties, such as dielectric switching, thermochromic properties, semiconductor characteristics and ferroelasticity. Under this context, we successfully synthesized [2-(2-fluorophenyl)ethan-1- ammonium] 2 SnBr 6 (compound 1), which has a higher phase transition temperature of 427.7 K. Additionally, it exhibits a semiconducting property with an indirect band gap of 2.36 eV. Combining ferroelastic, narrow band gap, thermochromic, and dielectric properties, compound 1 can be considered as a rarely reported multi-functional ferroelastic material, which is expected to give inspiration for broadening the applications in the smart devices field., (© 2022 Wiley-VCH GmbH.)

Curcumin (CUR) was encapsulated into yeast cells (YCs) through a pH-driven method with a 5.04-fold increase in loading capacity and a 43.63-fold reduction in incubation time compared to the conventional diffusion method. Optimal encapsulation was obtained when the mass ratio of CUR to YCs was 0.1, and the loading capacity and encapsulation efficiency were 8.07% and 80.66%, respectively. Encapsulation of CUR into YCs was confirmed by fluorescence microscopy, differential scanning calorimetry, and thermogravimetric analysis. Fourier transform infrared spectroscopy and X-ray diffraction further demonstrated that the encapsulated CUR was interacted with mannoprotein and β-glucan of the cell wall network through hydrophobic interaction and hydrogen bond in amorphous state. The in vitro bioaccessibility of YCs-loaded CUR was significantly increased by 6.05-fold. The enhanced encapsulation efficiency and rapid encapsulation process proposed in this study could facilitate YCs-based microcarriers to encapsulate bioactive substances with higher bioaccessibility., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

Molecular ferroelectrics have gradually aroused great interest in both fundamental scientific research and technological applications because of their easy processing, light weight and mechanical flexibility. Hybrid organic-inorganic perovskite ferroelectrics (HOIPFs), as a class of molecule-based ferroelectrics, have diverse functionalities owing to their unique structure and have become a hot spot in molecular ferroelectrics research. Therefore, they are extremely attractive in the field of ferroelectrics. However, there seems to be a lack of systematic review of their design, performance and potential applications. Herein, we review the recent development of HOIPFs from lead-based, lead-free and metal-free perovskites, and outline the versatility of these ferroelectrics, including piezoelectricity for mechanical energy-harvesting and optoelectronic properties for photovoltaics and light detection. Furthermore, a perspective view of the challenges and future directions of HOIPFs is also highlighted., (© The Author(s) 2022. Published by Oxford University Press on behalf of China Science Publishing & Media Ltd.)

Organic-inorganic hybrid phase transition materials with switchable properties have important potential applications in smart devices such as dielectric switches and storage. Nevertheless, it remains challenging to modify molecular structures efficiently to obtain materials simultaneously possessing multiple responsive properties. Herein, different from ordinary halogen substitutions in Metal Halide, we report a halogen regulation design of organic molecular strategy: (ASD) 2 MnBr 4 (ASD=5-azonia-spiro [4.5] decane) to (CASD) 2 MnBr 4 (CASD=8-chloro-5-azonia-spiro [4.5] decane). After organic molecular halogen regulation, the SHG response was excited and the dielectric phase transition temperature (T c ) has also been greatly improved. Furthermore, under the irradiation of UV lamp, both showed green light with quantum yields above 50%. This work is of great significance for further exploration of multifunctional molecular switch materials through halogen modification strategies., (© 2022 Wiley-VCH GmbH.)

Molecular ferroelastics have received particular attention for potential applications in mechanical switches, shape memory, energy conversion, information processing, and solar cells, by taking advantages of their low-cost, light-weight, easy preparation, and mechanical flexibility. The unique structures of organic-inorganic hybrid perovskites have been considered to be a design platform for symmetry-breaking-associated order-disorder in lattice, thereby possessing great potential for ferroelastic phase transition. Herein, we review the research progress of organic-inorganic hybrid perovskite ferroelastics in recent years, focusing on the crystal structures, dimensions, phase transitions and ferroelastic properties. In view of the few reports on molecular-based hybrid ferroelastics, we look forward to the structural design strategies of molecular ferroelastic materials, as well as the opportunities and challenges faced by molecular-based hybrid ferroelastic materials in the future. This review will have positive guiding significance for the synthesis and future exploration of organic-inorganic hybrid molecular ferroelastics., (© 2022 Wiley-VCH GmbH.)

A new multi-functional organic-inorganic hybrid compound was successfully obtained by regulating metal halides. Apart from excellent luminescence properties, in particular, the introduction of a Mn halide successfully achieved a dual-switchable dielectric property, which could lead to very interesting exploration in sensors.

Lead-free Halides, especially Mn-based ones, are preferred as hotspots in the exploration of photoluminescent materials. However, there are few reports on sensitive reversible thermochromism and switchable dual emission originating from self-trapped exciton emission in pure Mn-Based materials. Here, we report a new Mn-based hybrid material [TMPA] 2 MnI 4 (TMPA = trimethylphenylammonium), which shows two emission peaks at 545 and 660 nm benefitting from the d-d orbital transition of Mn 2+ and the generation of self-trapped excitons, respectively. Due to the different sensitivity to temperature, the stages of thermal activation and thermal quenching of the two emission types are also inconsistent, showing a certain competition relationship and dominating the emission colors in different temperature ranges, resulting in adjustable green-orange-green thermochromic luminescence from 100 to 403 K (both high and low temperatures correspond to green, and orange is displayed at near room temperature). Therefore, thermochromic luminescence can be easily achieved by controlling the temperature under the guidance of excited states. This work provides new insights into the synthesis and application of thermochromic materials. Therefore, it is certain that regulating temperature while being guided by excited states will achieve thermochromic luminescence. This research offers fresh perspectives on the development and potential of thermochromic materials.

Organic-inorganic hybrid materials with switchable properties have significant potential applications in intelligent devices. There are some conventional ways to obtain optical and/or electric multiple responses, such as asymmetric design, chirality, doping, and structural dimension in hybrid materials. Among them, the homochirality strategy is one of the best ways to regulate the molecular structure and symmetry, thereby ensuring second-harmonic generation (SHG) and dielectric dual response characteristics. Here, we report a homochiral design strategy to obtain noncentrosymmetric [ R -(HASD)][Cd(SCN) 3 ] (HASD = 7-hydroxy-5-azaspiro[4.5]decan) and [ S -(HASD)][Cd(SCN) 3 ]; [ Rac -(HASD)][Cd(SCN) 3 ] was also synthesized as a comparative experiment to illustrate the relationship between structural chirality and physical properties. With the help of homochiral regulation, the SHG response is excited and dielectric phase transition temperature ( T c ) is also highly improved. In addition, both the optical SHG and dielectric phase change show an optical/electric switchable response. This work is of great significance for the further exploration of multifunctional molecular switching materials through homochiral chemistry.

Hybrid organic-inorganic perovskite (HOIP) have received tremendous scientific attention because of the phase transition and photovoltaic properties. However, achieving the special perovskite structure with both two-step dielectric response and luminescence characteristics is rarely reported. Herein, we report an organic-inorganic hybrid perovskite, [(BA) 2  ⋅ PbI 4 ] (Compound 1, BA=n-butylamine) by introducing flexible organic cations (HBA + ), with direct mid-band gap as 2.28 eV. Interestingly, this material exhibits two-step reversible dielectric response at 350 K and 460 K (in heating process), respectively. Besides, the photoluminescence was found: it emits charming green light under 365 nm lamp (Photoluminescence quantum yield is 9.52 %). The outstanding two-step dielectric response and luminescence characteristics of this compound might pave the way for the application of dielectric and ferroelectric functional materials in temperature sensors and mechanical switches., (© 2022 Wiley-VCH GmbH.)

Organic-inorganic hybrid materials have received extensive attention and in-depth research in the past few decades due to their superior properties and potential applications in storage, sensing, dielectric switches, actuators and other information fields. Based on this scientific background, we developed two organic-inorganic hybrids [TMFEA] 2 CdI 4 (compound 1) and [TMFEA] 2 ZnI 4 (compound 2) (TMFEA = trimethylfluoroethylammonium). Both compounds show transformable double channels of nonlinear optical and dielectric properties induced by structural phase transitions, which was proved by the thermal, nonlinear optical, and dielectric phase changes. In addition, the channels can be switched ON and OFF by temperature regulation. This work will provide inspiration and options for the exploration of opto-electrical dual channel components.

As a feasible lead-free scheme, organic-inorganic hybrid double perovskites show many excellent properties, including ferroelectricity, ferroelasticity, self-powered circularly polarized light detection and so on. In this work, the solid-to-solid structural phase transition of a two-dimensional hybrid double perovskite (CHA) 4 CuBiI 8 was successfully activated via the dehydration of (CHA) 4 CuBiI 8 ·H 2 O, which was proven by differential scanning calorimetry (DSC) and temperature-dependent dielectric measurements. Using variable-temperature single-crystal X-ray diffractometry, the cause behind the phase transition of (CHA) 4 CuBiI 8 was determined to be the overall coordination of distortion and movement of the inorganic skeleton and thermal deformation of the cationic structure. In addition, the substance after dehydration shows good stability in multiple reversible switching during dielectric tests. The interesting dehydration-activated results of the material contribute towards a further expansion of the properties and potential application of hybrid double perovskites.

Two-dimensional (2D) hybrid double perovskites have attracted extensive research interest for their fascinating physical properties, such as ferroelectricity, X-ray detection, light response and so on. In addition, ferroelastics, as an important branch of ferroic materials, exhibits wide prospects in mechanical switches, shape memory and templating electronic nanostructures. Here, we designed a 2D phase-transition double perovskite ferroelastic through a structurally progressive strategy. This evolution is core to our construction process from 0D to 1D and AgBi-based 2D. In this way, we successfully synthesized 2D lead-free ferroelastic (DPA) 4 AgBiBr 8 (DPA = 2,2-dimethylpropan-1-aminium) with a high Curie temperature ( T c ), which shows a narrower band gap than 0D (DPA) 4 Bi 2 Br 10 and 1D (DPA) 5 Pb 2 Br 9 . Moreover, the mechanism of structural phase transition and molecular motion are fully characterized by temperature dependent solid-state NMR and single crystal XRD. (DPA) 4 AgBiBr 8 injects power into the discovery of new ferroelastics or the construction and dimensional adjustment in new hybrid double perovskites., Competing Interests: The authors declare no conflict of interest., (This journal is © The Royal Society of Chemistry.)

Multifunctional switching materials show great potential for applications in sensors, smart switches, and other fields due to their ability to integrate different physical channels in one single device. However, multifunctional responsive materials with multiple switching and luminescence properties have rarely been reported. Here, we report three organic-inorganic hybrids: [TMAA] 2 [CoCl 4 ] (compound 1), [TMAA] 2 [CdBr 4 ] (compound 2) and [TMAA] 2 [MnCl 4 ] (compound 3). Compound 1 and compound 2 undergo two reversible phase transitions at high temperature (328.95/359.25 K and 350.45/393.15 K, respectively). Since the inorganic skeleton has a strong influence on the luminescence properties of such structured substances, Cd and Co were replaced with Mn, after which compound 3 was obtained as expected. The above strategy triggered bright green luminescence with a quantum yield of 35.19%, and significantly increased the phase transition temperature of compound 3 to above 400 K. The above results show that the regulation of the inorganic skeleton provides a new strategy for researchers to develop dual phase change/luminous materials.

Massive efforts have been devoted to designing molecular ferroic materials by molecular modification. For molecular ferroelastic, previous work is focused on the temperature-dependent ferroelastic domains, however, few are related to controlling the ferroelastic domain by the stress. Inspired by the "quasi-spherical theory" and fluorination effect, we designed a more flexible (MedabcoF) 2+ (MedabcoF=1-fluoro-4-methyl-1,4-diazoniabicyclo[2.2.2]octane) cation by introducing a methyl group and a fluorine atom at the two symmetrical ends of the Dabco (1,4-diazoniabicyclo[2.2.2]octane) and synthesized a hybrid 3D perovskite (MedabcoF)Rb(BF 4 ) 3 (1) which displays three reversible phase transitions accompanying dual ferroelastic behavior. Besides, it not only exhibits ferroelastic domains switching by the thermal stimulation, and the sensitive reaction of in situ domains under the stress of it is also realized. This work not only achieves a force-controlled ferroelastic domain but develops a more profound comprehension of the relationship between the thermal motion behavior of guest cations and the intriguing properties of materials., (© 2021 Wiley-VCH GmbH.)

The strict tolerance space of three-dimensional (3D) crystalline structures is still a significant challenge in the area of switching dielectrics in comparison with lower-dimensional structures. Generally, the function of crystalline materials can be given or adjusted by controlling the environment in which synthesis takes place or the packing rearrangement. Using this method, special functional enhancements or changes in the dielectrics can be realized by improving the synthetic strategies. Here, a 3D switchable dielectric compound [MeHdabco]K(BF4)3 was achieved by employing the temperature selective effect. In particular, its structure is completely different from the usual 3D perovskite structure, which is constructed using two different cation-template frameworks. Moreover, the 3D [MeHdabco]K(BF4)3 shows a structural phase transition at 358 K. The thermal analysis (differential scanning calorimetry (DSC)) and X-ray diffractometry results provided evidence of these phase changes. This work provides a feasible strategy that can be used to achieve the different structures of an 'isomer', and enrich the method used for designing diverse functional materials.

Solid-state molecular rotor-type materials such as host-guest inclusion compounds are very desirable for the construction of molecular ferroelectrics. However, they usually have a low Curie temperature ( T c ) and uniaxial nature, severely hindering their practical applications. Herein, by regulating the anion to control "momentum matching" in the crystal structure, we successfully designed a high-temperature multiaxial host-guest inclusion ferroelectric [(MeO-C 6 H 4 -NH 3 )(18-crown-6)][TFSA] (MeO-C 6 H 4 -NH 3 = 4-methoxyanilinium, TFSA = bis(trifluoromethanesulfonyl)ammonium) with the Aizu notation of mmm F m . Compared to the parent uniaxial ferroelectric [(MeO-C 6 H 4 -NH 3 )(18-crown-6)][BF 4 ] with a T c of 127 K, the introduction of larger TFSA anions brings a lower crystal symmetry at room temperature and a higher energy barrier of molecular motions in phase transition, giving [(MeO-C 6 H 4 -NH 3 )(18-crown-6)][TFSA] multiaxial ferroelectricity and a high T c up to 415 K (above that of BaTiO 3 ). To our knowledge, such a record temperature enhancement of 288 K makes its T c the highest among the reported crown-ether-based ferroelectrics, giving a wide working temperature range for applications in data storage, temperature sensing, actuation, and so on. This work will provide guidance and inspiration for designing high- T c host-guest inclusion ferroelectrics.

Organic ferroelectrics are highly desirable for their light weight, mechanical flexibility and biocompatibility. However, the rational design of organic ferroelectrics has always faced great challenges. Anilinium bromide (AB) has two structures reported in the Cambridge Crystallographic Data Centre, which might be an mmmF2/m type ferroelastic (AB-1). When we studied its ferroelasticity, we were surprised to discover that there was another crystal (AB-2) in H 2 O besides this one, and they were very difficult to separate. By changing the solvent, we found that AB-1 crystals could be formed in ethanol, where ferroelastic domains were visualized by polarized light microscopy, and AB-2 crystals could be obtained from various crystallization solvents of methanol, isopropanol, N-butanol, acetonitrile, dimethyl sulfoxide, and N,N-dimethylformamide, which undergo a ferroelectric phase transition with mm2Fm, showing clear ferroelectricity in two phases. To our knowledge, the regulation of ferroelasticity to ferroelectricity by solvent selective effect is unprecedented in the field of ferroelectrics. This work reveals the important role of solvent effect in organic ferroelectrics., (© 2021 Wiley-VCH GmbH.)

Organic-inorganic hybrid ABX 3 perovskite (OIHPs) with phase transition have considerable application potential in multifunctional devices for their structural tunability and excellent photo/electric performance. Because the interaction between molecules during the crystallization process is difficult to predict and control, exploring targeted chemical design methods to synthesize phase change materials has been an interesting and challenging problem. As per the synergistic effect of anion and cation, we assemble a cation with high vibrational activity and an inorganic anion with large voids to successfully design a one-dimensional OIHPs phase change material. [FMPD][Cd(SCN) 3 ] (FMPD = 1-fluoroethyl-1-methylpiperidinium) undergoes two reversible phase transitions above room temperature with the substitution of methyl with fluoroethyl increasing the energy barrier of molecular motion. The individual crystal diffraction structures show that, unlike the phase change caused by the reorientation of organic cations in majority of known perovskites, this phase transition is triggered by the order/disorder of cations and anions related to the vibration increase by the introduction of fluoroethyl. The results provide a new design idea for the design and assembly of novel OIHPs-type phase change materials.

Molecular phase transition compounds have become a hot research area in recent years because of their potential as functional materials, such as ferroelectrics, ferroelastics, dielectric switches, etc. However, materials combining switchable dielectric properties and ferroelasticity are still rare. Here, we reported an organic-inorganic hybrid perovskite, [CPtmp][Cd(SCN) 3 ] ( 1 ) ([CPtmp] + is a cyclopentyltrimethylphosphonium cation), with a potential ferroelastic property. This material undergoes three structural phase transitions at 247/226, 335/312, and 349/341 K (upon heating/cooling). The successive phase transitions are mainly caused by the stepwise ordering of [CPtmp] + cations and the concomitant deformation of [Cd(SCN) 3 ] - anionic chains revealed by structural analyses, which triggers the double-step dielectric switching in 1 as well. These results would inspire further exploration on molecular dielectric switches with ferroelastic properties.

A semiconductor material [(CH 2 ) 3 NH 2 S] 2 BiCl 5 (1) exhibits dielectric switching and Pd uptake functions. The thioether group in 1 provides an opportunity for Pd uptake. After 1 adsorbs Pd, the dielectric switching disappears, so that Pd adsorption can be monitored by dielectric measurements. Moreover, the material becomes an insulator after adsorbing Pd.

Phase transitions of hybrid materials have aroused widespread concern and call for an in-depth study on its structure design, because the structure and characteristics are closely related, which promote potential applications in the field of temperature sensors, dielectric switches, and actuators. However, designing materials with multiple phase transitions and a high phase transition temperature (Tr) remains a huge challenge. In order to deal with this key hurdle, we tried to regulate the structural components and successfully synthesized [MASD] 2 [CdCl 4 ] ( 1 , MASD = 8-methyl-5-azoniaspiro[4,5]decane), which displays multiple phase transitions occurring at 273.8 K and 395.9 K separately. The Tr has significantly increased compared with the parent compounds reported previously. As the temperature sensitivity of compound 1 is constant at different frequencies, it can be applied for detectors or sensors under frequency-independent or wide frequency conditions. Moreover, methylation design strategy evidently triggered the dual dielectric switch and improved the Tr, which opens a new path for finding and adjusting ideal materials of multiple phase transition.

In the last decade, hybrid materials have received widespread attention. In particular, hybrid lead halide perovskite-type semiconductors are very attractive owing to their great flexibility in band gap engineering. Here, by using precise molecular modifications, three one-dimensional perovskite-type semiconductor materials are designed and obtained: [Me 3 PCH 2 X][PbBr 3 ] (X=H, F, and Cl for compounds 1, 2, and 3, respectively). The introduction of a heavier halogen atom (F or Cl) to [Me 4 P] + increases the potential energy barrier required for the tumbling motion of the cation, hence achieving the transformation of the phase transition temperature from low temperature (192 K) to room temperature (285 K) and high temperature (402.3 K). Moreover, the optical band gaps reveal a broadening trend with 3.176 eV, 3.215 eV, and 3.376 eV along the H→F→Cl series, which is attributed to the formation of the structural distortion., (© 2020 Wiley-VCH GmbH.)

Molecular perovskite materials have recently attracted extraordinary interest from the academic community owing to their excellent multifunctional properties. Nevertheless, although massive efforts have been made, molecular ferroelastics with three-dimensional (3D) perovskite structures are still rare. Herein, we report two 3D organic-inorganic hybrid perovskites [(2-hydroxy-propyl)-tripropyl-ammonium][Mn(dca) 3 ] ( 1 ) and [(2-hydroxy-1-methyl-ethyl)-tripropyl-ammonium] [Mn(dca) 3 ] ( 2 ) [dca = dicyanamide, N(CN) 2 ]. The different position of the chiral center results in a tremendous difference in the properties. Compound 1 displays only one phase transition; however, intriguingly, 2 has three phase transitions and represents ferroelastic behavior with exceptional two-step switching of quadratic nonlinear optical (NLO) properties. To the best of our knowledge, this is the first molecular ferroelastic with two-step switching of quadratic NLO properties. The results demonstrate that the molecular chiral design works, and this finding opens up a new avenue to designing multifunctional molecular perovskite materials.