Search

Organic single-component ferroelectrics with low molecular mass have drawn great attention for applications in organic electronics. However, the discovery of high-Tc single-component organic ferroelectrics has been very scarce. Herein, we report a pair of homochiral single-component organic ferroelectrics (R)-10-camphorsulfonylimine and (S)-10-camphorsulfonylimine under the guidance of ferroelectric chiral chemistry. They crystallize in chiral-polar space group P21, and their mirror image relations have been identified by vibrational circular dichroism spectra. They both exhibit 422F2 multiaxial ferroelectricity with Tc as high as 429 K. Besides, they possess superior acoustic impedance characteristic with the value of 2.45×106 kg·s-1·m-2, lower than that of PVDF. To our knowledge, enantiomeric (R and S)-10-camphorsulfonylimine show the highest Tc among the known organic single-component ferroelectrics and the low acoustic impedance well matching with the bodily tissues. This work promotes the development of high-performance organic single-component ferroelectrics and is of great inspiration to explore the applications in next-generation flexible smart devices.

H/F substitution successfully constructs unprecedented switchable C–F–K coordination bonds in a three-dimensional cyano-bridged double perovskite ferroelastic [(CH3)3NCH2F]2[KFe(CN)6].

Chirality exists everywhere from natural amino acids to particle physics. The introduction of point chirality has recently been shown to be an efficient strategy for the construction of molecular ferroelectrics. In contrast to point chirality, however, axial chirality is rarely used to design ferroelectrics so far. Here, based on optically active 1,1'-bi-2-naphthol (BINOL), which has been applied extensively as a versatile chiral reagent in asymmetric catalysis, chiral recognition, and optics, we successfully design a pair of axial-chiral BINOL multiferroics, (

Since the discovery of the first ferroelectric Rochelle salt, most ferroelectrics have been investigated showing thermally triggered symmetry-breaking phase transition. Although photochromism arising from geometrical isomerization has been reported earlier in 1867, such photoswitchable ferroelectric crystals have scarcely been developed to date. Herein, we report that salicylideneaniline is a photochromic ferroelectric crystal. Upon photoirradiation, the dielectric constant shows obvious switching between high and low dielectric states, and more importantly, the ferroelectric polarization demonstrates quickly and reversibly switching. This work opens the gate of developing photoswitchable ferroelectrics, which holds great potential for applications in optically controlled smart devices.

Since the discovery of TEMPO (2,2,6,6-tetramethylpiperidine-N-oxyl) in 1973, organic radical ferroics attracted widespread interest among the scientific community. However, the relatively low Curie temperature of 287 K and melting point of 311 K severely hinder its application potential. Despite extensive interest, high-temperature radical ferroics have not been found to date. Here, taking advantage of chemical design theory and supramolecular radical chemistry, we successfully designed two high-temperature organic supramolecular radical ferroics [(NH3-TEMPO)([18]crown-6)](ReO4) (1) and [(NH3-TEMPO)([18]crown-6)](ClO4) (2), which can retain the ferroelectricity up to 413 K and 450 K, respectively. To our knowledge, they are both the first supramolecular radical ferroics and unprecedented high-temperature radical ferroics, where the supramolecular component plays a vital role in the stabilization of radical and extending working temperature window. Additionally, both of them can also present the paramagnetism and non-interacting spin moments, as well as excellent piezoelectric and electrostrictive behaviors comparable to that of LiNbO3. This work provides an efficient design strategy for enriching the family of high-temperature radical ferroics, and should inspire further exploration of multi-functional organic ferroics.

Multiferroic materials have attracted great interest because of their underlying new science and promising applications in data storage and mutual control devices. However, they are still very rare and highly imperative to be developed. Here, we report an organic–inorganic hybrid perovskite trimethylchloromethylammonium chromium chloride (TMCM–CrCl3), showing the coexistence of magnetic and electric orderings. It displays a paraelectric–ferroelectric phase transition at 397 K with an Aizu notation of 6/mFm, and spin-canted antiferromagnetic ordering with a Néel temperature of 4.8 K. The ferroelectricity originates from the orientational ordering of TMCM cations, and the magnetism is from the [CrCl3]− framework. Remarkably, TMCM–CrCl3 is the first experimentally confirmed divalent Cr2+-based multiferroic material as far as we know. A new category of hybrid multiferroic materials is pointed out in this work, and more Cr2+-based multiferroic materials will be expectedly developed in the future., An organic–inorganic hybrid perovskite Trimethylchloromethylammonium chromium(ii) chloride (TMCM–CrCl3) can simultaneously show excellent ferroelectricity and antiferromagnetism, which is the first experimentally confirmed Cr2+-based multiferroic material.

Chiral perovskites have emerged as a significant class of materials showing promising optoelectronic and spintronic applications. Reports of chiral perovskite ferroelectrics, however, have been scarce. In this work, we have successfully synthesized homochiral lead-iodide perovskite ferroelectrics [(R)-N-(1-phenylethyl)ethane-1,2-diaminium]PbI4 and [(S)-N-(1-phenylethyl)ethane-1,2-diaminium]PbI4 by the chemical design of introducing a methyl group into the organic cation of the parent (N-benzylethane-1,2-diaminium)PbI4. Vibrational circular dichroism spectra identify the chiral mirroring relationship. They both undergo 222F2 type paraelectric-ferroelectric behavior at around 378 K coupled with clear ferroelastic domains "ON/OFF" switching. Besides, they exhibit an evident thermochromism with color change from orange-yellow to orange-red. To our knowledge, the discovery of integrated ferroelectricity, ferroelasticity and reversible thermochromism in chiral perovskites is unprecedented. This finding offers a resultful path to design chiral perovskite ferroelectrics and is of great inspiration to the discovery of multifunctional perovskite materials.

The well-developed design strategy of molecular modification for assembling molecular ferroelectrics mainly focuses on the cations. Herein, by homochiral anionic modification of the non-ferroelectric (quinuclidinium)(HSO4), we designed high-temperature multiaxial organic enantiomeric ferroelectrics, (quinuclidinium)(L- and D-camphorsulfonate). This work paves a new road for precisely constructing excellent molecular ferroelectrics.

An organic molecular-ionic crystal of (TPPO–H)2SO4 exhibits moderate NLO response which is twice that of KDP and competing hydrogen-bonding interactions triggered high-Tc phase transition.

The optical manipulation of polarization has gained widespread attention because it offers a promising route to new contactless memories and switches. However, the current research basically focuses on the photocontrol of data storage rather than data reading, which cannot realize the whole process of contactless write-read-erase data storage. Here, we present a pair of enantiomorphic diarylethene derivative ferroelectric crystals, showing a light-driven phase transition triggered by photoisomerization between the open and closed forms. Under the visible light, they exhibit a binary-domain state in the open form with white color and the band gap of 3.26 eV, while they show a single-domain state in the closed form with blue color and the band gap of 1.68 eV after UV irradiation of 254/365 nm. In addition to writing and erasing ferroelectric domains with light, we can also use light to read their color to determine the polarization state of domains. Moreover, diarylethene derivatives have better thermal stability, higher photoexcited conversion efficiency, and larger changes of the absorption wavelength between two isomers than those in salicylideneaniline derivatives. This work not only discovers the first diarylethene-based ferroelectric crystals but also successfully realizes completely contactless manipulation of write-read-erase data storage in the organic ferroelectric semiconductors.

Many indexes have been demonstrated to evaluate the lodging resistance of rice, but most of them are complex or not representative. Thus, we propose a simple and low-cost index, called relative culm wall thickness (RCWT), which can be calculated as the ratio of the basal internode wall thickness to its diameter, to measure the lodging characteristics of rice. A field experiment with 20 indica hybrid rice varieties was conducted in Dayi, Sichuan, China, in 2017 and 2018. The results show that RCWT was significantly negatively correlated with the lodging index, visual lodging rate, plant inclination angle, and bending moment, while it was significantly positively correlated with culm wall thickness, breaking resistance, cellulose, and lignin. Compared with the middle and low RCWT types, the high RCWT type had a lower plant height and center of gravity. Meanwhile, the short basal internodes, thick culm wall thickness, and small pith diameter increased the fullness of the stem, which increased the content of cellulose and lignin in the stem, and thus enhanced the bending resistance and decreased lodging index of the stem. These results indicate that the RCWT can be used as an important index to evaluate the lodging resistance of rice.

A ferroelectric/ferroelastic is a material whose spontaneous polarization/strain can be switched by applying an external electric field/mechanical stress. However, the optical control of spontaneous polarization/strain remains relatively unexplored in crystalline materials, although photoirradiation stands out as a nondestructive, noncontact, and remote-controlled stimulus beyond stress or electric field. Here, we present two new organic single-component homochiral photochromic multiferroics, (

The optical control of polarization switching is attracting tremendous interest because photoirradiation stands out as a nondestructive, noncontact, and remote-control means beyond an electric or strain field. The current research mainly uses various photoexcited electronic effects to achieve the photocontrol polarization, such as a light-driven flexoelectric effect and a photovoltaic effect. However, since photochromism was discovered in 1867, the structural phase transition caused by photoisomerization has never been associated with ferroelectricity. Here, we successfully synthesized an organic photochromic ferroelectric with polar space group Pna21, 3,4,5-trifluoro-N-(3,5-di-tert-butylsalicylidene)aniline, whose color can change between yellow and orange via laser illumination. Its dielectric permittivity and spontaneous polarization can be switched reversibly with a photoinduced phase transition triggered by structural photoisomerization between the enol form and the trans-keto form. To our knowledge, this is the first photoswitchable ferroelectric crystal to achieve polarization switching through a structural phase transition triggered by photoisomerization. This finding paves the way toward photocontrol of smart materials and biomechanical applications in the future.

Organic single-component ferroelectrics with low molecular mass have drawn great attention for application in organic electronics. However, the discovery of high

Background To verify the differential expression of miR‐30c and miR‐142‐3p between tuberculosis patients and healthy controls and to investigate the performance of microRNA (miRNA) and subsequently models for the diagnosis of tuberculosis (TB). Methods We followed up 460 subjects suspected of TB, and finally enrolled 132 patients, including 60 TB patients, 24 non‐TB disease controls (TB‐DCs), and 48 healthy controls (HCs). The differential expression of miR‐30c and miR‐142‐3p in serum samples of the TB patients, TB‐DCs, and HCs were identified by reverse transcription–quantitative real‐time PCR. Diagnostic models were developed by analyzing the characteristics of miRNA and electronic health records (EHRs). These models evaluated by the area under the curves (AUC) and calibration curves were presented as nomograms. Results There were differential expression of miR‐30c and miR‐142‐3p between TB patients and HCs (p, Integrating serum microRNAs and electronic health recordsis a good strategy for improving the diagnosis of tuberculosis (TB): we analyzed the expression of miR‐30c and miR‐142‐3p among TB patients, healthy controls and non‐TB disease controls. And integrating miRNA and electronic health records to develop diagnostic models of TB, we found integrating serum microRNAs and electronic health records is a good strategy for improving TB diagnosis.

Topological defects such as vortices in ferroelectric materials are attracting tremendous interest because of their splendid possibilities for unique physical phenomena and potential applications in nanoelectronic devices. However, reports of the vortex structure have been scarce in organic ferroelectrics, which are highly desirable for their mechanical flexibility, easy and environment-friendly processing, and low acoustical impedance. Here, we successfully observed the robust triangular domains in a single-component organic ferroelectric, 2-(hydroxymethyl)-2-nitro-1,3-propanediol (1), six of which can form a 6-fold vertex domain structure. To our knowledge, it is the first time that such an intriguing topological vortex gets experimentally confirmed in ferroelectrics. Moreover, the symmetry change of 1 with an Aizu notation of m3mF1 leads to the most 48 crystallographically equivalent polarization directions among all ferroelectrics. With those benefits and excellent piezoelectric properties, compound 1 shows great potential as a reconfigurable electronic element or a mechanical sensor for soft robotics, flexible and wearable devices, and biomachines.

For a century ferroelectricity has attracted widespread interest from science and industry. Inorganic ferroelectric ceramics have dominated multibillion dollar industries of electronic ceramics, ranging from nonvolatile memories to piezoelectric sonar or ultrasonic transducers, whose polarization can be reoriented in multiple directions so that they can be used in the ceramic and thin-film forms. However, the realization of macroscopic ferroelectricity in the polycrystalline form is challenging for molecular ferroelectrics. In pursuit of low-cost, biocompatible, and mechanically flexible alternatives, the development of multiaxial molecular ferroelectrics is imminent. Here, from quinuclidinium perrhenate, we applied fluorine substitution to successfully design a multiaxial molecular ferroelectric, 3-fluoroquinuclidinium perrhenate ([3-F-Q]ReO4), whose macroscopic ferroelectricity can be realized in both powder compaction and thin-film forms. The fluorination effect not only increases the intrinsic polarization but also reduces the coercive field strength. More importantly, it is also, as far as we know, the softest of all known molecular ferroelectrics, whose low Vickers hardness of 10.5 HV is comparable with that in poly(vinylidene difluoride) (PVDF) but almost 2 orders of magnitude lower than that in BaTiO3. These attributes make it an ideal candidate for flexible and wearable devices and biomechanical applications.

A high transition temperature (Tc ) is essential for the practical application of ferroelectrics as electronic devices under extreme thermal conditions in the aerospace, automotive, and energy industries. In recent decades, the isotope effect and strain engineering are found to effectively modulate Tc ; however, these strategies are limited to certain systems. Developing simple, universal, and practical methods to improve Tc has become an imminent challenge for expanding the applications of ferroelectrics. Here, by adopting a molecular design strategy involving H/F substitution on an organic-inorganic hybrid perovskite (1-azabicyclo[2.2.1]heptane)CdCl3 at a Tc of 190 K, the successful synthesis of a multiaxial, ferroelectric hybrid perovskite (4-fluoro-1-azabicyclo[2.2.1]heptane)CdCl3 is reported, which demonstrates a large spontaneous polarization of 11.2 µC cm-2 (greater than that of polyvinylidene difluoride) and a Tc of 419 K (greater than that of BaTiO3 ). This temperature enhancement (229 K) is the largest reported for molecular ferroelectrics, far exceeding the reported enhancements induced by the isotope effect and other techniques. This pioneering technique provides an effective and universal method for improving Tc in ferroelectrics and represents an important step toward the development of high-performance ferroelectric technology.

The optimal number layer of concentric circles is calculated by the distance.We calculate the optimum number of relay nodes to forward the data.Analysis of the characteristics of the energy model.Our proposed architectures can effectively reduce energy consumption of nodes. This paper proposes two architectures, including an Opportunistic Large Array Concentric Routing Algorithm with Geographic Relay Nodes (OLACRA-GRN) architecture, and an Opportunistic Large Array Concentric Routing Algorithm with Relay Nodes (OLACRA-RN) architecture. First, the OLACRA-GRN architecture with the geographic information of relay nodes reduces node energy consumption and finds the optimum number of relay nodes to forward the data; an analysis of the characteristics of the energy model is also presented. Besides, the OLACRA-RN architecture without the geographic information of relay nodes is proposed, which can find the number layer of concentric circles in the sensing field. The optimal number layer of concentric circles is calculated according to the distance between the sink and field boundary. Simulation results show that our proposed OLACRA-GRN and OLACRA-RN architectures can effectively reduce node energy consumption more than Opportunistic Large Array Concentric Routing Algorithm (OLACRA) architecture. Display Omitted

Wireless sensor networks (WSNs) are a group of wireless sensor nodes, those sensor nodes with sensing and monitoring of environmental information. Energy consumption is an important topic; the node's power is limited. Therefore, we proposed an Opportunistic Large Array Concentric Geographic Routing Algorithm (OLACGRA) to reduce the node’s energy consumption and analysis the characteristic of energy model. The sink position of our proposed OLACGRA is at the center of concentric topology architecture. The source node wants to transmit data that it needs to calculate the distance between source node and sink node. If this distance bigger than threshold value, we use the multi-hop manner. Otherwise, source node transmits data to sink node directly. Simulation results show that our proposed algorithm can effectively reduce the node’s energy consumption.

Porphyrin, despite chosen by Nature as light har- vesting units, hasn't revealed its full potentials as a structural unit in porphyrin-incorporated polymers (PPors). A novel PPor was synthesized to investigate the origins of the low perform- ances of PPor-based polymer solar cells (PSCs). The polymer features broad absorption in the blue-light region, because the diindenothieno(2,3-b)thiophene (DITT) unit extended the conju- gation in the polymer backbone. PPor-DITT/PC71BM based PSCs have a high Voc (0.79 V). Their low Jsc and fill factor (FF) were attributed to the un-optimized morphology, as indicated by the photoluminescence quenching and atomic force micros- copy (AFM) experiments. Using PPor-DITT as a blue-light har- vesting dopant in an amorphous host leverage the strong 400- 550 nm absorption of PPor-DITT and circumvent the difficulties in reaching optimized morphology in the PPor/PCBM thin films. An addition of 2 wt % of PPor-DITT in ternary-blend PSCs resulted in a 10 % increase of external quantum effi- ciency (EQE) in the blue-light region. However, in a crystalline host, the dopant decreased the crystallinity of the host and led to large drops in FF and power conversion efficiencies (PCEs). The study provides an alternative route and expands the appli- cation of PPors in PSCs as a blue-light harvester in ternary- blend PSCs using amorphous polymers as host. V C 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 50: 5032- 5040, 2012

Self-assembled, chair-shaped dirhenium(I) macrocyclic compounds featuring the two different bis-chelating quinone dianions (1, L = dhnq(2-); 2, L = dhaq(2-); H(2)dhnq = 6,11-dihydroxy-5,12-naphthacenedione; H(2)dhaq = 1,4-dihydroxy-9,10-anthraquinone) that interface with two fac-Re(CO)(3) cores and a ditopic semirigid N-donor 1,4-bis(5,6-dimethylbenzimidazol-1-ylmethyl)naphthalene (L' = p-NBimM) ligand coordinated to the remaining orthogonal site were prepared in high yields. Their structures were confirmed by single-crystal X-ray diffraction analysis. Electrochemical assessments, using cyclic voltammetry (CV) and UV-vis-NIR spectroelectrochemistry (SEC), revealed the existence of two well-separated, single-electron quinone ligand-centered, reversibly accessible 0, -1, and -2 redox states. Among the two singly reduced radical complexes, the symmetrically bridged quinone complex 1(•-), showed a strong absorption in the NIR regions, which was not observed for the neutral and doubly reduced states, analogous to that of the free dhnq(3•-) quinone. In contrast, when 2 was reduced to 2(•-), a broad signal at 866 nm was observed, very similar to the reduced dhaq(3•-) quinone. This difference in spectral behavior in the singly reduced states is likely due to the annealed benzene ring in 1 and dhnq(2-) because of its symmetrical π-electron system, which is perturbed to a lesser degree compared to asymmetric 2 and dhaq(2-). Reduction to 1(•-) produces a small but not negligible g factor anisotropy (Δg = 0.024) in the electron spin resonance (ESR) signal, indicative of a very small metal-centered spin (5%), but 2(•-) shows a g value in the expected range for organic radicals (no detectable Δg). Thus, the combined investigations reveal that the singly reduced metallacycles are best described as being highly stable, noncommunicating, localized, quinonoid-centered radical complexes, [(CO)(3)Re(I)(μ-L(3•-))(μ-L')Re(I)(CO)(3)](•-).

A bradykinin potentiating peptide (BPP), Thr-Pro-Pro-Ala-Gly-Pro-Asp-Val-Gly-Pro-Arg-OH, was isolated from the venoms of Crotalus viridis viridis (here named Cvv peptide). Compared with other BPP, Cvv peptide has special Thr at N-terminal and Arg at C-terminal. In order to clarify whether these two special amino acids lead to special bioactivities relative to other BPPs, we made bioassays on isolated guinea pig ileum (GPI) and rat stomach fundus. Cvv peptide can observably inhibit bradykinin's contractivity on GPI, but potentiate the bradykinin-induced contractivity on rat stomach fundus. The discrepant bioactivity of Cvv peptide may occur via binding different receptors, B2 receptor on GPI and anaphylatoxin C3a receptor on rat stomach fundus, respectively.