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1.
Adv Mater ; : e2405981, 2024 Jul 06.
Article in English | MEDLINE | ID: mdl-38970528

ABSTRACT

Ferroelectric materials, traditionally comprising inorganic ceramics and polymers, are commonly used in medical implantable devices. However, their nondegradable nature often necessitates secondary surgeries for removal. In contrast, ferroelectric molecular crystals have the advantages of easy solution processing, lightweight, and good biocompatibility, which are promising candidates for transient (short-term) implantable devices. Despite these benefits, the discovered biodegradable ferroelectric materials remain limited due to the absence of efficient design strategies. Here, inspired by the polar structure of polyvinylidene fluoride (PVDF), a ferroelectric molecular crystal 1H,1H,9H,9H-perfluoro-1,9-nonanediol (PFND), which undergoes a cubic-to-monoclinic ferroelectric plastic phase transition at 339 K, is discovered. This transition is facilitated by a 2D hydrogen bond network formed through O-H···O interactions among the oriented PFND molecules, which is crucial for the manifestation of ferroelectric properties. In this sense, by reducing the number of -CF2- groups from ≈5 000 in PVDF to seven in PFND, it is demonstrated that this ferroelectric compound only needs simple solution processing while maintaining excellent biosafety, biocompatibility, and biodegradability. This work illuminates the path toward the development of new biodegradable ferroelectric molecular crystals, offering promising avenues for biomedical applications.

2.
BMC Ophthalmol ; 24(1): 270, 2024 Jun 24.
Article in English | MEDLINE | ID: mdl-38914965

ABSTRACT

BACKGROUND: This study aimed to explore differences in vitreous humour metabolites and metabolic pathways between patients with and without diabetic retinopathy (DR) and identify potential metabolite biomarkers. METHODS: Clinical data and vitreous fluid samples were collected from 125 patients (40 without diabetes, 85 with DR). The metabolite profiles of the vitreous fluid samples were analysed using ultra-high performance liquid chromatography, Q-Exactive mass spectrometry, and multivariate statistical analysis. A machine learning model based on Least Absolute Shrinkage and Selection Operator Regularized logistic regression was used to build a risk scoring model based on selected metabolite levels. Candidate metabolites were regressed to glycated haemoglobin levels by a logistic regression model. RESULTS: Twenty differential metabolites were identified between the DR and control groups and were significantly enriched in five Kyoto Encyclopedia of Genes and Genomes pathways (arginine biosynthesis; tricarboxylic acid cycle; alanine, aspartate, and glutamate metabolism; tyrosine metabolism; and D-glutamate metabolism). Ferrous ascorbate significantly contributes to poorer glycaemic control outcomes, offering insights into potential new pathogenic pathways in DR. CONCLUSIONS: Disorders in the metabolic pathways of arginine biosynthesis, tricarboxylic acid cycle, alanine, aspartate, glutamate metabolism, tyrosine metabolism, and D-glutamate metabolism were associated with DR. Risk scores based on vitreous fluid metabolites can be used for the diagnosis and management of DR. Ferrous ascorbate can provide insights into potential new pathogenic pathways for DR.


Subject(s)
Ascorbic Acid , Biomarkers , Diabetic Retinopathy , Metabolomics , Vitreous Body , Humans , Diabetic Retinopathy/metabolism , Diabetic Retinopathy/diagnosis , Vitreous Body/metabolism , Biomarkers/metabolism , Male , Metabolomics/methods , Female , Middle Aged , Ascorbic Acid/metabolism , Aged , Chromatography, High Pressure Liquid
3.
Org Lett ; 26(20): 4229-4234, 2024 May 24.
Article in English | MEDLINE | ID: mdl-38738828

ABSTRACT

A copper-catalyzed [3 + 2] annulation of O-acyl oximes with 4-sulfonamidophenols is developed. The advantage of this method lies in the concurrent double activation of two substrates to form nucleophilic enamines and electrophilic quinone monoimines. The substituent on the α-carbon of O-acyl oxime determines two different reaction pathways, thereby leading to the selective generation of 5-sulfonamidoindoles and 2-amido-5-sulfonamidobenzofuran-3(2H)-ones.

4.
ACS Appl Mater Interfaces ; 16(19): 25065-25070, 2024 May 15.
Article in English | MEDLINE | ID: mdl-38712510

ABSTRACT

Phase transition materials with switchable second-order nonlinear optical (NLO) properties have attracted extensive attention because of their great application potential in photoelectric switches, sensors, and modulators, while metal-free organics with NLO switchability near room temperature remain scarce. Herein, we report a hydrogen-bonded metal-free organic crystal, 2-methylpropan-2-aminium 2,2-dimethylpropanoate (1), exhibiting a room-temperature phase transition and favorable NLO switchability. Through investigations on its thermal anomalies, dielectric properties, and crystal structures, we uncover that 1 holds a near-room-temperature phase transition at 303 K from noncentrosymmetric point group C2v to centrosymmetric one D2h, which is attributed to the order-disorder transformations of both tert-butylamine cations and dimethylpropionic acid anions. Accompanied by symmetry change during the phase transition, 1 exhibits reversible and repeatable NLO "on-off" switchability with a desirable switching contrast ratio of ca. 19 between high and low NLO states. This discovery demonstrates a metal-free organic crystal with NLO switching behavior near room temperature, serving as a promising candidate in smart and ecofriendly photoelectric functional materials and devices.

5.
Int J Hematol ; 119(5): 564-572, 2024 May.
Article in English | MEDLINE | ID: mdl-38441775

ABSTRACT

OBJECTIVE: To describe the features of ETV6::ABL1 AML as well as the clinical treatment and outcomes. METHODS: Clinical data were collected from three patients diagnosed with ETV6::ABL1 AML at Hebei Yanda Lu Daopei Hospital and Beijing Lu Daopei Hospital. Their clinical and laboratory features were analyzed, and the treatment process and outcomes were described. Ten reported cases of ETV6::ABL1 AML from the literature were also included for analysis. RESULTS: The median age of the patients was 34 years, and 2 patients were male. No patient had a history of blood disorders before diagnosis. After relapse, they were referred to our hospital, where the ETV6::ABL1 gene was detected. Unfortunately, Patient 1 died rapidly after leukemia relapse due to severe infection. Patients 2 and 3 received salvage therapy with a dasatinib-containing regimen, followed by allo-HSCT, and are currently alive and disease-free. CONCLUSION: ETV6::ABL1 is a rare but recurrent genetic aberration in AML, and the combined use of fluorescence in situ hybridization and PCR can better identify this fusion gene. Patients carrying ETV6::ABL1 have a high relapse rate and a poor prognosis. TKIs are a reasonable treatment option for this group, and allo-HSCT may be curative.


Subject(s)
ETS Translocation Variant 6 Protein , Leukemia, Myeloid, Acute , Oncogene Proteins, Fusion , Proto-Oncogene Proteins c-ets , Repressor Proteins , Adult , Female , Humans , Male , Middle Aged , Hematopoietic Stem Cell Transplantation , Leukemia, Myeloid, Acute/genetics , Leukemia, Myeloid, Acute/diagnosis , Leukemia, Myeloid, Acute/therapy , Oncogene Proteins, Fusion/genetics , Proto-Oncogene Proteins c-abl/genetics , Proto-Oncogene Proteins c-ets/genetics , Repressor Proteins/genetics , Treatment Outcome
6.
Arch Biochem Biophys ; 754: 109962, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38499055

ABSTRACT

Acetohydroxyacid synthase (AHAS) is one of the key enzymes of the biosynthesis of branched-chain amino acids, it is also an effective target for the screening of herbicides and antibiotics. In this study we present a method for preparing Escherichia coli AHAS I holoenzyme (EcAHAS I) with exceptional stability, which provides a solid ground for us to re-investigate the in vitro catalytic properties of the protein. The results show EcAHAS I synthesized in this way exhibits similar function to Bacillus subtilis acetolactate synthase in its catalysis with pyruvate and 2-ketobutyrate (2-KB) as dual-substrate, producing four 2-hydroxy-3-ketoacids including (S)-2-acetolactate, (S)-2-aceto-2-hydroxybutyrate, (S)-2-propionyllactate, and (S)-2-propionyl-2-hydroxybutyrate. Quantification of the reaction indicates that the two substrates almost totally consume, and compound (S)-2-aceto-2- hydroxybutyrate forms in the highest yield among the four major products. Moreover, the protein also condenses two molecules of 2-KB to furnish (S)-2-propionyl-2-hydroxybutyrate. Further exploration manifests that EcAHAS I ligates pyruvate/2-KB and nitrosobenzene to generate two arylhydroxamic acids N-hydroxy-N-phenylacetamide and N-hydroxy-N-phenyl- propionamide. These findings enhance our comprehension of the catalytic characteristics of EcAHAS I. Furthermore, the application of this enzyme as a catalyst in construction of C-N bonds displays promising potential.


Subject(s)
Acetolactate Synthase , Escherichia coli , Acetolactate Synthase/chemistry , Glycogen Synthase , Hydroxybutyrates , Pyruvates , Holoenzymes
7.
Fitoterapia ; 175: 105928, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38548027

ABSTRACT

α-DCs (α-dicarbonyls) have been proven to be closely related to aging and the onset and development of many chronic diseases. The wide presence of this kind of components in various foods and beverages has been unambiguously determined, but their occurrence in various phytomedicines remains in obscurity. In this study, we established and evaluated an HPLC-UV method and used it to measure the contents of four α-DCs including 3-deoxyglucosone (3-DG), glyoxal (GO), methylglyoxal (MGO), and diacetyl (DA) in 35 Chinese herbs after they have been derivatized with 4-nitro-1,2-phenylenediamine. The results uncover that 3-DG is the major component among the α-DCs, being detectable in all the selected herbs in concentrations ranging from 22.80 µg/g in the seeds of Alpinia katsumadai to 7032.75 µg/g in the fruit of Siraitia grosuenorii. The contents of the other three compounds are much lower than those of 3-DG, with GO being up to 22.65 µg/g, MGO being up to 55.50 µg/g, and DA to 18.75 µg/g, respectively. The data show as well the contents of the total four α-DCs in the herbs are generally in a comparable level to those in various foods, implying that herb medicines may have potential risks on human heath in view of the α-DCs.


Subject(s)
Deoxyglucose , Drugs, Chinese Herbal , Glyoxal , Pyruvaldehyde , Drugs, Chinese Herbal/chemistry , Drugs, Chinese Herbal/analysis , Pyruvaldehyde/analysis , Chromatography, High Pressure Liquid , Deoxyglucose/analogs & derivatives , Deoxyglucose/analysis , Glyoxal/analysis , Diacetyl/analysis , Molecular Structure , Fruit/chemistry , Plants, Medicinal/chemistry , Seeds/chemistry
8.
Science ; 383(6690): 1492-1498, 2024 Mar 29.
Article in English | MEDLINE | ID: mdl-38547269

ABSTRACT

Transient implantable piezoelectric materials are desirable for biosensing, drug delivery, tissue regeneration, and antimicrobial and tumor therapy. For use in the human body, they must show flexibility, biocompatibility, and biodegradability. These requirements are challenging for conventional inorganic piezoelectric oxides and piezoelectric polymers. We discovered high piezoelectricity in a molecular crystal HOCH2(CF2)3CH2OH [2,2,3,3,4,4-hexafluoropentane-1,5-diol (HFPD)] with a large piezoelectric coefficient d33 of ~138 picocoulombs per newton and piezoelectric voltage constant g33 of ~2450 × 10-3 volt-meters per newton under no poling conditions, which also exhibits good biocompatibility toward biological cells and desirable biodegradation and biosafety in physiological environments. HFPD can be composite with polyvinyl alcohol to form flexible piezoelectric films with a d33 of 34.3 picocoulombs per newton. Our material demonstrates the ability for molecular crystals to have attractive piezoelectric properties and should be of interest for applications in transient implantable electromechanical devices.


Subject(s)
Biocompatible Materials , Ferric Compounds , Polymers , Biodegradation, Environmental , Polymers/chemistry , Polymers/metabolism , Polyvinyl Alcohol/chemistry , Polyvinyl Alcohol/metabolism , Biocompatible Materials/chemistry , Biocompatible Materials/metabolism , Electricity , Animals , Rats , Rats, Sprague-Dawley , Ferric Compounds/chemistry , Ferric Compounds/metabolism
9.
Blood Adv ; 8(7): 1639-1650, 2024 Apr 09.
Article in English | MEDLINE | ID: mdl-38315878

ABSTRACT

ABSTRACT: The phase 3 ASPEN trial (NCT03053440) compared Bruton tyrosine kinase inhibitors (BTKis), zanubrutinib and ibrutinib, in patients with Waldenström macroglobulinemia (WM). Post-hoc biomarker analysis was performed using next-generation sequencing on pretreatment bone marrow samples from 98 patients treated with zanubrutinib and 92 patients treated with ibrutinib with mutated (MUT) MYD88 and 20 patients with wild-type (WT) MYD88 treated with zanubrutinib. Of 329 mutations in 52 genes, mutations in CXCR4 (25.7%), TP53 (24.8%), ARID1A (15.7%), and TERT (9.0%) were most common. TP53MUT, ARID1AMUT, and TERTMUT were associated with higher rates of CXCR4MUT (P < .05). Patients with CXCR4MUT (frameshift or nonsense [NS] mutations) had lower very good partial response (VGPR) and complete response rates (CR; 17.0% vs 37.2%, P = .020) and longer time to response (11.1 vs 8.4 months) than patients with CXCR4WT treated with BTKis. CXCR4NS was associated with inferior progression-free survival (PFS; hazard ratio [HR], 3.39; P = .017) in patients treated with ibrutinib but not in those treated with zanubrutinib (HR, 0.67; P = .598), but VGPR + CR rates were similar between treatment groups (14.3% vs 15.4%). Compared with ibrutinib, patients with CXCR4NS treated with zanubrutinib had a favorable major response rate (MRR; 85.7% vs 53.8%; P = .09) and PFS (HR, 0.30; P = .093). In patients with TP53MUT, significantly lower MRRs were observed for patients treated with ibrutinib (63.6% vs 85.7%; P = .04) but not for those treated with zanubrutinib (80.8% vs 81.9%; P = .978). In TP53MUT, compared with ibrutinib, patients treated with zanubrutinib had higher VGPR and CR (34.6% vs 13.6%; P < .05), numerically improved MRR (80.8% vs 63.6%; P = .11), and longer PFS (not reached vs 44.2 months; HR, 0.66; P = .37). Collectively, patients with WM with CXCR4MUT or TP53MUT had worse prognosis compared with patients with WT alleles, and zanubrutinib led to better clinical outcomes.


Subject(s)
Adenine/analogs & derivatives , Piperidines , Pyrazoles , Pyrimidines , Waldenstrom Macroglobulinemia , Humans , Waldenstrom Macroglobulinemia/drug therapy , Waldenstrom Macroglobulinemia/genetics , Myeloid Differentiation Factor 88/genetics , Biomarkers
10.
Vaccines (Basel) ; 12(2)2024 Feb 19.
Article in English | MEDLINE | ID: mdl-38400198

ABSTRACT

Zika virus (ZIKV) is an emerging flavivirus that causes congenital syndromes including microcephaly and fetal demise in pregnant women. No commercial vaccines against ZIKV are currently available. We previously generated a chimeric ZIKV (ChinZIKV) based on the Chaoyang virus (CYV) by replacing the prME protein of CYV with that of a contemporary ZIKV strain GZ01. Herein, we evaluated this vaccine candidate in a mouse model and showed that ChinZIKV was totally safe in both adult and suckling immunodeficient mice. No viral RNA was detected in the serum of mice inoculated with ChinZIKV. All of the mice inoculated with ChinZIKV survived, while mice inoculated with ZIKV succumbed to infection in 8 days. A single dose of ChinZIKV partially protected mice against lethal ZIKV challenge. In contrast, all the control PBS-immunized mice succumbed to infection after ZIKV challenge. Our results warrant further development of ChinZIKV as a vaccine candidate in clinical trials.

11.
J Ginseng Res ; 48(1): 103-111, 2024 Jan.
Article in English | MEDLINE | ID: mdl-38223831

ABSTRACT

Background: Ginseng (Panax ginseng Mayer) is an important natural medicine. However, a long culture period and challenging quality control requirements limit its further use. Although artificial cultivation can yield a sustainable medicinal supply, research on the association between the transplantation and chaining of metabolic networks, especially the regulation of ginsenoside biosynthetic pathways, is limited. Methods: Herein, we performed Liquid chromatography tandem mass spectrometry based metabolomic measurements to evaluate ginsenoside accumulation and categorise differentially abundant metabolites (DAMs). Transcriptome measurements using an Illumina Platform were then conducted to probe the landscape of genetic alterations in ginseng at various ages in transplantation mode. Using pathway data and crosstalk DAMs obtained by MapMan, we constructed a metabolic profile of transplantation Ginseng. Results: Accumulation of active ingredients was not obvious during the first 4 years (in the field), but following transplantation, the ginsenoside content increased significantly from 6-8 years (in the wild). Glycerolipid metabolism and Glycerophospholipid metabolism were the most significant metabolic pathways, as Lipids and lipid-like molecule affected the yield of ginsenosides. Starch and sucrose were the most active metabolic pathways during transplantation Ginseng growth. Conclusion: This study expands our understanding of metabolic network features and the accumulation of specific compounds during different growth stages of this perennial herbaceous plant when growing in transplantation mode. The findings provide a basis for selecting the optimal transplanting time.

13.
Adv Mater ; 36(8): e2307936, 2024 Feb.
Article in English | MEDLINE | ID: mdl-37907064

ABSTRACT

Ferroelectric lithography, which can purposefully control and pattern ferroelectric domains in the micro-/nanometer scale, has extensive applications in data memories, field-effect transistors, race-track memory, tunneling barriers, and integrated biochemical sensors. In pursuit of mechanical flexibility and light weight, organic ferroelectric polymers such as poly(vinylidene fluoride) are developed; however, they still suffer from complicated stretching processes of film fabrication and poor degradability. These poor features severely hinder their applications. Here, the ferroelectric lithography on the biocompatible and biodegradable poly(lactic acid) (PLA) thin films at room temperature is demonstrated. The semicrystalline PLA thin film can be easily fabricated through the melt-casting method, and the desired domain structures can be precisely written according to the predefined patterns. Most importantly, the coercive voltage (Vc ) of PLA thin film is relatively low (lower than 30 V) and can be further reduced with the decrease of the film thickness. These intriguing behaviors combined with satisfying biodegradability make PLA thin film a desirable candidate for ferroelectric lithography and enable its future application in the field of bioelectronics and biomedicine. This work sheds light on further exploration of ferroelectric lithography on other polymer ferroelectrics as well as their application as nanostructured devices.

14.
J Biomed Mater Res A ; 112(2): 296-306, 2024 02.
Article in English | MEDLINE | ID: mdl-37850566

ABSTRACT

Angiogenesis has been determined to be essential in the occurrence and metastasis of diabetic retinopathy (DR), age-related macular degeneration (AMD), retinal vein occlusion (RVO), choroidal neovascularization (CNV), retinopathy of prematurity (ROP), tumor, etc. However, the clinical use of anti-vascular endothelial growth factors (VEGF) drugs is currently limited due to its high cost, potential side effects, and need for repeated injections. In recent years, nanotechnology has shown promising results in inhibiting neovascularization and reducing reactive oxygen species (ROS) or inflammatory factors. Some nanomaterials can also act as vehicles for drug delivery, such as lipid nanoparticles and PLGA. The process of angiogenesis and its molecular mechanism are discussed in this article. At the same time, this study aims to systematically review the research progress of nanotechnology and offer more treatment options for neovascularization-related diseases in clinical ophthalmology.


Subject(s)
Choroidal Neovascularization , Diabetic Retinopathy , Macular Degeneration , Humans , Infant, Newborn , Angiogenesis Inhibitors/pharmacology , Angiogenesis Inhibitors/therapeutic use , Choroidal Neovascularization/drug therapy , Diabetic Retinopathy/chemically induced , Diabetic Retinopathy/drug therapy , Injections , Macular Degeneration/drug therapy , Vascular Endothelial Growth Factor A/antagonists & inhibitors
15.
Front Plant Sci ; 14: 1208549, 2023.
Article in English | MEDLINE | ID: mdl-38078092

ABSTRACT

PAMP-induced secreted peptide (PIP), one of the small post-translationally modified peptides (PTMPs), plays a crucial role in plant development and stress tolerance. However, little is known about functional divergence among this peptide family. Here, we studied the evolution of the PIP family in 23 plant species (10 monocotyledons and 13 dicotyledons from 7 families) and their functional divergence in Arabidopsis. A total of 128 putative PIP precursors were identified and classified into two subfamilies through phylogenetic analysis. Functional studies on AtPIP1 which represents Clade I family and AtPIP2 which represents Clade II family have shown that AtPIP2 displayed stronger immunity induction activity but weaker root growth inhibition than AtPIP1 in Arabidopsis. Transcriptome analysis of Arabidopsis seedlings treated with AtPIP1 and AtPIP2 showed that differential genes for both polypeptides were significantly enriched in similar plant defense pathways. However, Co-expression and Protein-protein interaction (PPI) analysis showed that the functions of AtprePIP2 co-expressed genes were more enriched in plant defense pathways than AtprePIP1. Molecular docking results show that AtPIP1 binds to RLK7 receptor with a more stable free energy and less binding area than AtPIP2, while hydrogen bond transfer occurs at the SGP motif position. The above results suggest that the PIP family have undergone functional divergence during evolution. Collectively, this work illustrates the relationship between PIP structure and function using Arabidopsis PIP as an example, and provides new insights into the current understanding between growth inhibition and immune responses which may be correlated but not fully coupled.

16.
J Clin Med ; 12(23)2023 Dec 04.
Article in English | MEDLINE | ID: mdl-38068537

ABSTRACT

BACKGROUND: Dry eye disease (DED) is a common chronic condition with increasing prevalence. Standard discriminative visual acuity is not reflective of real-world visual function, as patients can achieve normal acuities by blinking. METHODS: Participants recruited from a tertiary referral eye centre were divided into two groups-Severe DED (with significant, central staining) and Mild DED (absence of such staining). Functional Visual Acuity (FVA) in both groups was assessed using the DryeyeKT mobile application and Impact of Vision Impairment (IVI) questionnaire to assess quality of life (QOL). RESULTS: Among the 78 participants (74.4% women), 30 (38.5%) had Severe DED and 48 (61.5%) Mild DED. In women, Severe DED produced a significantly worse FVA of 0.53 ± 0.20 vs. 0.73 ± 0.30 in the Mild DED group (p = 0.006). FVA decreased with increasing age, showing a significant inverse correlation (r = -0.55). A poorer FVA ≤ 0.6 was seen in older patients (68.2 years ± 7.68) vs. an FVA > 0.6 in younger patients (58.9 years ± 10.7), p < 0.001. When adjusting for age, FVA was still 0.107 lower in the Severe DED group, p = 0.003. There was significant difficulty in performing specific daily activities in the Severe DED group, after adjusting for age, gender and FVA. CONCLUSIONS: FVA is reduced in severe DED and older people. Severe DED significantly impacts certain aspects of QOL. However, no significant relationship was found between FVA and QOL. FVA is not the only reason for the compromise of health-related QOL in severe dry eye.

17.
Angew Chem Int Ed Engl ; 62(51): e202315189, 2023 Dec 18.
Article in English | MEDLINE | ID: mdl-37919233

ABSTRACT

Thermally triggered spatial symmetry breaking in traditional ferroelectrics has been extensively studied for manipulation of the ferroelectricity. However, photoinduced molecular orbital breaking, which is promising for optical control of ferroelectric polarization, has been rarely explored. Herein, for the first time, we synthesized a homochiral fulgide organic ferroelectric crystal (E)-(R)-3-methyl-3-cyclohexylidene-4-(diphenylmethylene)dihydro-2,5-furandione (1), which exhibits both ferroelectricity and photoisomerization. Significantly, 1 shows a photoinduced reversible change in its molecular orbitals from the 3 π molecular orbitals in the open-ring isomer to 2 π and 1 σ molecular orbitals in the closed-ring isomer, which enables reversible ferroelectric domain switching by optical manipulation. To our knowledge, this is the first report revealing the manipulation of ferroelectric polarization in homochiral ferroelectric crystal by photoinduced breaking of molecular orbitals. This finding sheds light on the exploration of molecular orbital breaking in ferroelectrics for optical manipulation of ferroelectricity.

18.
Inorg Chem ; 62(49): 19930-19936, 2023 Dec 11.
Article in English | MEDLINE | ID: mdl-37990884

ABSTRACT

Organic-inorganic hybrid perovskites (OIHPs) have been emerging as a hot research topic due to their potential applications in energy storage, semiconductors, and electronic devices. Herein, we systematically investigated the synthesis and phase transition behaviors of the enantiomeric OIHPs, (R) and (S)-N,N-dimethyl-3-fluoropyrrolidinium cadmium bromide ([DMFP][CdBr3]), and the hybrid trigonal structure [DMFP]3 (CdBr3)(CdBr4). The enantiomers have a mirror-symmetric structure and enhanced solid-state phase transition points of 417 and 443 K, in contrast to the nonfluorinated parent compound, N,N-dimethyl-pyrrolidinium cadmium bromide ([DMP][CdBr3], 385 K). Moreover, racemic H/F substitution on the pyrrolidinium cations leads to the formation of a trigonal compound, showing above-room-temperature structural phase transition and dominant ferroelasticity. This work discovers chiral enantiomeric OIHPs through H/F substitution, demonstrating a useful chemical synthesis strategy for exploring novel phase transition materials.

19.
J Am Chem Soc ; 145(42): 23292-23299, 2023 Oct 25.
Article in English | MEDLINE | ID: mdl-37819908

ABSTRACT

Fullerenes offer versatile functionalities and are promising materials for a widespread range of applications from biomedicine and energy to electronics. Great efforts have been made to manipulate the symmetries of fullerene and its derivatives for studying material properties and novel effects, such as ferroelectricity with polar symmetry; however, no documentary report has been obtained to realize their ferroelectricity. Here, for the first time, we demonstrated clear ferroelectricity in a fullerene adduct formed by C60 and S8. More is different: the combination of the most symmetric molecule C60 with the highest Ih symmetry and molecule S8 with high D4d symmetry resulted in the polar C60S8 adduct with a low crystallographic symmetry of the C2v (mm2) point group at room temperature. The presented C60S8 undergoes polar-to-polar ferroelectric phase transition with the mm2Fm notation, whose ferroelectricity was confirmed by a ferroelectric hysteresis loop and ferroelectric domain switching. This finding opens up a new functionality for fullerenes and sheds light on the exploration of more ferroelectric fullerenes.

20.
Adv Mater ; 35(44): e2305471, 2023 Nov.
Article in English | MEDLINE | ID: mdl-37607776

ABSTRACT

As particles carry quantified energy, photon radiation enables orbital transitions of energy levels, leading to changes in the spin state of electrons. The resulting switchable structural bistability may bring a new paradigm for manipulating ferroelectric polarization. However, the studies on molecular orbital breaking in the ferroelectric field remain blank. Here, for the first time, a new mechanism of ferroelectrics-dual breaking of molecular orbitals and spatial symmetry, demonstrated in a photochromic organic crystal with light-induced polarization switching, is formally proposed. By alternating the ultraviolet/visible light irradiation, the states of electron spin and the radial distribution p atomic orbitals experience a change, showing a reversible switch from "shoulder-to-shoulder" form to a "head-to-head" form. This reflects a reversible conversion between π and σ bonds, which induces and couples with the variation of spatial symmetry. The intersection of spatial symmetry breaking and molecular orbital breaking in ferroelectrics present in this work will be more conducive to data encryption and anticounterfeiting.

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