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1.
Chemistry ; 26(1): 139-142, 2020 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-31680317

RESUMO

Cyclic naphthalene diimides (cNDIs), with a ferrocene moiety (cFNDs) and different linker lengths between the ferrocene and cNDI moieties, were designed and synthesized as redox-active, tetraplex-DNA ligands. Intramolecular stacking was observed between ferrocene and the NDI planes, which could affect the binding properties for G-quadruplexes. Interestingly, the circular dichroism spectrum of one of these compounds clearly shows new Cotton effects around 320-380 and 240 nm, which can be considered a direct evidence of intramolecular stacking of ferrocene and the NDI. Regarding recognition of hybrid G-quadruplexes, the less rigid structures (longer linkers) show higher binding affinity (106 m-1 order of magnitude). All new compounds show higher selectivity for G4 during electrochemical detection than noncyclic FND derivatives, which further identifies the redox-active potentiality of the cFNDs. Two of the three compounds tested even show preferential inhibition of cell growth in cancer cells over normal cells in a low concentration range, highlighting the potential for bioapplications of these cFNDs.


Assuntos
Compostos Ferrosos/química , Quadruplex G , Imidas/química , Metalocenos/química , Naftalenos/química , Sobrevivência Celular/efeitos dos fármacos , Dicroísmo Circular , Células HeLa , Humanos , Imidas/farmacologia , Ligantes , Naftalenos/farmacologia , Oxirredução , Telômero/química
2.
Chemistry ; 26(2): 390-395, 2020 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-31596010

RESUMO

Dearomatisation of indole derivatives to the corresponding isatin derivatives has been achieved with the aid of visible light and oxygen. It should be noted that isatin derivatives are highly important for the synthesis of pharmaceuticals and bioactive compounds. Notably, this chemistry works excellently with N-protected and protection-free indoles. Additionally, this methodology can also be applied to dearomatise pyrrole derivatives to generate cyclic imides in a single step. Later this methodology was applied for the synthesis of four pharmaceuticals and a pesticide called dianthalexin B. Detailed mechanistic studies revealed the actual role of oxygen and photocatalyst.


Assuntos
Indóis/química , Luz , Praguicidas/química , Preparações Farmacêuticas/química , Pirróis/química , Catálise , Imidas/química , Praguicidas/síntese química , Preparações Farmacêuticas/síntese química
3.
Chemosphere ; 240: 124947, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31568943

RESUMO

This work studies the effect of the cation and anion on the biodegradability and inhibition of imidazolium- and choline-based ionic liquids (ILs) using activated sludge. Six commercial ILs, formed by combination of 1-Butyl-3-methylimidazolium (Bmim+) and N,N,N-trimethylethanolammonium (Choline+) cations and chloride (Cl-), acetate (Ac-) and bis(trifluoromethanesulfonyl)imide (NTf2-) anions were evaluated, all representative counter-ions with markedly different toxicity and biodegradability. Inherent and fast biodegradability tests were used to evaluate both the microorganism inhibition and the IL biodegradability. In addition, the ecotoxicological response (EC50) of the ILs was studied using activated sludge and Vibrio fischeri (Microtox® test). Bmim+ and NTf2- can be considered as non-biodegradable, whereas aerobic microorganisms easily degraded Choline+ and Ac-. The biodegradation pattern of each cation/anion is nearly unaffected by counter-ion nature. Moreover, concentrations of CholineNTf2 higher than 50 mg/L caused a partial inhibition on microbial activity, in good concordance with its low EC50 (54 mg/L) measured by respiration inhibition test, which alerts on the negative environmental impact of NTf2-containing ILs on the performance of sewage treatment plants.


Assuntos
Aliivibrio fischeri/efeitos dos fármacos , Biodegradação Ambiental , Colina/análise , Hidrocarbonetos Fluorados/química , Imidazóis/análise , Imidazóis/química , Imidas/química , Compostos de Amônio Quaternário/química , Ecotoxicologia , Líquidos Iônicos/análise , Esgotos/química , Purificação da Água/métodos
4.
Chem Commun (Camb) ; 55(95): 14335-14338, 2019 Nov 26.
Artigo em Inglês | MEDLINE | ID: mdl-31720600

RESUMO

A syn-atropisomer of naphthalene diimide as a highly preorganized precursor was used to construct a type of trapezoid-shape macrocycle, namely 'trapezoid' molecular boxes (TBox). As supramolecular hosts, TBox can bind electron-rich guests and selectively recognize free tryptophan and tryptophanyl residues from 20 standard amino acids.


Assuntos
Imidas/química , Compostos Macrocíclicos/química , Naftalenos/química , Triptofano/análise
5.
Phys Chem Chem Phys ; 21(32): 17950-17958, 2019 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-31384849

RESUMO

The A. aeolicus intrinsically disordered protein FlgM has four well-defined α-helices when bound to σ28, but in water FlgM undergoes a change in tertiary structure. In this work, we investigate the structure of FlgM in aqueous solutions of the ionic liquid [C4mpy][Tf2N]. We find that FlgM is induced to fold by the addition of the ionic liquid, achieving average α-helicity values similar to the bound state. Analysis of secondary structure reveals significant similarity with the bound state, but the tertiary structure is found to be more compact. Interestingly, the ionic liquid is not homogeneously dispersed in the water, but instead aggregates near the protein. Separate simulations of aqueous ionic liquid do not show ion clustering, which suggests that FlgM stabilizes ionic liquid aggregation.


Assuntos
Proteínas de Bactérias/química , Imidas/química , Proteínas Intrinsicamente Desordenadas/química , Líquidos Iônicos/química , Modelos Moleculares , Pirrolidinas/química , Bases de Dados de Proteínas , Conformação Proteica em alfa-Hélice , Dobramento de Proteína , Termodinâmica , Água
6.
J Enzyme Inhib Med Chem ; 34(1): 1465-1473, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31411081

RESUMO

In this investigation, we studied a family of compounds with an oxathiazolidine-4-one-2,2-dioxide skeleton and their amide synthetic precursors as new anticonvulsant drugs. The cyclic structures were synthesized using a three-step protocol that include solvent-free reactions and microwave-assisted heating. The compounds were tested in vivo through maximal electroshock seizure test in mice. All the structures showed activity at the lower doses tested (30 mg/Kg) and no signs of neurotoxicity were detected. Compound encoded as 1g displayed strong anticonvulsant effects in comparison with known anticonvulsants (ED50 = 29 mg/Kg). First approximations about the mechanisms of action of the cyclic structures were proposed by docking simulations and in vitro assays against sodium channels (patch clamp methods).


Assuntos
Anticonvulsivantes/química , Anticonvulsivantes/farmacologia , Desenho de Drogas , Imidas/química , Imidas/farmacologia , Tiazóis/química , Animais , Anticonvulsivantes/administração & dosagem , Anticonvulsivantes/síntese química , Espectroscopia de Ressonância Magnética Nuclear de Carbono-13 , Relação Dose-Resposta a Droga , Células HEK293 , Humanos , Imidas/síntese química , Masculino , Camundongos , Canal de Sódio Disparado por Voltagem NAV1.1/efeitos dos fármacos , Óxidos/química , Técnicas de Patch-Clamp , Espectroscopia de Prótons por Ressonância Magnética
7.
Chemistry ; 25(62): 14214-14222, 2019 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-31452291

RESUMO

A series of new ruthenium(II) vinyl complexes has been prepared incorporating perylenemonoimide (PMI) units. This fluorogenic moiety was functionalised with terminal alkyne or pyridyl groups, allowing attachment to the metal either as a vinyl ligand or through the pyridyl nitrogen. The inherent low solubility of the perylene compounds was improved through the design of poly-PEGylated (PEG=polyethylene glycol) units bearing a terminal alkyne or a pyridyl group. By absorbing the compounds on silica, vapours and gases could be detected in the solid state. The reaction of the complexes [Ru(CH=CH-PerIm )Cl(CO)(py-3PEG)(PPh3 )2 ] and [Ru(CH=CH-3PEG)Cl(CO)(py-PerIm )(PPh3 )2 ] with carbon monoxide, isonitrile or cyanide was found to result in modulation of the fluorescence behaviour. The complexes were observed to display solvatochromic effects and the interaction of the complexes with a wide range of other species was also studied. The study suggests that such complexes have potential for the detection of gases or vapours that are toxic to humans.


Assuntos
Monóxido de Carbono/análise , Cianetos/análise , Corantes Fluorescentes/química , Imidas/química , Nitrilos/análise , Perileno/análogos & derivados , Rutênio/química , Alquinos/química , Monóxido de Carbono/toxicidade , Complexos de Coordenação/química , Cianetos/toxicidade , Nitrilos/toxicidade , Perileno/química , Piridinas/química
8.
J Phys Chem Lett ; 10(19): 5861-5867, 2019 Oct 03.
Artigo em Inglês | MEDLINE | ID: mdl-31464127

RESUMO

Circularly polarized luminescence (CPL) reflects the excited-state properties of the chiral system. However, compared to the singlet and triplet excited states, there are still many unknowns about CPL from the double excited state. Here, using the self-assembly strategy of a dipeptide substituted naphthalenediimide (NDI-GE) and the photogenerated radical anions, we have explored the ground-state (CD) and excited-state (CPL) chiral characteristics of neutral NDI and NDI•- radical anion assemblies. The neutral gelator assemblies showed CPL with the dissymmetry factor glum on the order of 10-3; the radical anion exhibited an inversed CPL signal with a significantly enhanced glum of 10-1. Time-dependent density functional theory calculation revealed that upon formation of the radical anions, the direction of the dipole moment changed, thus leading to the inversion of CD and CPL. The present work reveals a new platform for developing CPL materials based on the doublet excited state.


Assuntos
Dipeptídeos/química , Imidas/química , Naftalenos/química , Ânions/química , Teoria da Densidade Funcional , Dimerização , Cinética , Luminescência , Modelos Químicos , Modelos Moleculares , Processos Fotoquímicos , Solventes/química
9.
Chemistry ; 25(52): 12137-12144, 2019 Sep 18.
Artigo em Inglês | MEDLINE | ID: mdl-31276238

RESUMO

Isomerism heavily influences the optoelectronic properties and self-assembly behavior of compounds and subsequently affects their device performance. Herein, two pairs of isomeric perylene diimide (PDI) dimers, PDI and PDI2, were designed and synthesized. The electron-deficient 9,10-anthraquinone group was employed as the bridge, and thus, the resultant dimers exhibited an acceptor-acceptor-acceptor (A-A-A) structure. To determine the isomeric effects on the optoelectronic properties and photovoltaic performance of these dimers, their absorptivity, luminescence, and redox behavior were studied. Bulk heterojunction organic solar cells based on these four dimers were fabricated and measured. The two PDI dimers exhibited clear differences in photovoltaic performance, whereas the two PDI2 analogues showed similar power conversion efficiencies (PCEs). The PCEs of the two PDI2 dimers are much higher than those of the PDI dimers. These results illustrate that the isomeric effect of PDI dimers is much larger than that of PDI2 dimers on the device performance, and proper expansion of conjugation could improve the device performance.


Assuntos
Antraquinonas/química , Imidas/química , Perileno/análogos & derivados , Dimerização , Eletrônica , Isomerismo , Oxirredução , Perileno/química , Energia Solar
10.
Molecules ; 24(11)2019 Jun 04.
Artigo em Inglês | MEDLINE | ID: mdl-31167411

RESUMO

In this article, we report the facile synthesis, self-assembly, and characterization of shape amphiphiles (BPOSS-PDI-X) based on isobutyl-functionalized polyhedral oligomeric silsesquioxane (BPOSS), perylene tetracarboxylic diimide (PDI), and (60)fullerene (C60) moieties. Firstly, an asymmetrically functionalized diblock shape amphiphile precursor (BPOSS-PDI-OH) was obtained through the one-pot reaction between perylene-3,4,9,10-tetracarboxylic dianhydride and two different amines, namely BPOSS-NH2 and 3-amino-1-propanol. It was further conjugated with C60-COOH to give a tri-block shape amphiphile (BPOSS-PDI-C60). Their chemical structures were thoroughly characterized by NMR, IR and MALDI-TOF MS spectrometry. In order to gain insights on the structure-property relationship, their self-assembly in gas phase, in solution, and in solid state were characterized using traveling wave ion mobility mass spectrometry (TWIM-MS), UV/Vis absorption, fluorescence emission spectrophotometer, and transmission electron microscopy, respectively. It was found that BPOSS-PDI-OH formed more complicated dimers than BPOSS-PDI-C60. Both samples showed unique aggregation behaviors in solution with increasing concentration, which could be attributed neither to H- nor to J-type and might be related to the discrete dimers. While BPOSS-PDI-C60 could hardly crystalize into ordered structures, BPOSS-PDI-OH could form nanobelt-shaped single crystals, which may hold potential applications in microelectronics.


Assuntos
Fulerenos/química , Imidas/química , Perileno/análogos & derivados , Tensoativos/química , Cristalinas/química , Cristalinas/metabolismo , Espectroscopia de Ressonância Magnética , Estrutura Molecular , Nanoestruturas , Perileno/química , Espectrometria de Massas por Ionização por Electrospray/métodos
11.
Chemistry ; 25(42): 9834-9839, 2019 Jul 25.
Artigo em Inglês | MEDLINE | ID: mdl-31173417

RESUMO

Introduction of chirality into a supramolecular self-assembly system plays an indispensable role in attaining specific molecular recognition ability. Herein, a chiral anticancer drug 5'-deoxy-5-fluorouridine (5'DFU) was explored for inducing the self-assembly of a cationic perylene diimide derivative containing boronic acid groups (PDI-PBA) into a highly ordered right-handed helical structure. As a result, PDI-PBA exhibited a molecular recognition ability towards 5'DFU among other cis-diols and anticancer drugs. With the help of a dynamic covalent bond and favorable hydrogen-bonding interactions, chirality transfer from chiral 5'DFU to achiral PDI-PBA breaks down the strong π-π stacking of PDI-PBA and makes it reorganize into highly ordered helical supramolecular structures. This work provides an insight into chiral anticancer drug tuning interactions of π-chromophores and the inducement of hierarchical self-assembly to achieve specific molecular recognition.


Assuntos
Antineoplásicos/química , Corantes Fluorescentes/química , Imidas/química , Perileno/análogos & derivados , Ácidos Borônicos/química , Ligações de Hidrogênio , Modelos Moleculares , Conformação Molecular , Perileno/química , Espectrometria de Fluorescência , Estereoisomerismo , Termodinâmica
12.
Adv Mater ; 31(33): e1901965, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31237375

RESUMO

Antibacterial photocatalytic therapy has been reported as a promising alternative water disinfection technology for combating antibiotic-resistant bacteria. Numerous inorganic nanosystems have been developed as antibiotic replacements for bacterial infection treatment, but these are limited due to the toxicity risk of heavy metal species. Organic semiconductor photocatalytic materials have attracted great attention due to their good biocompatibility, chemically tunable electronic structure, diverse structural flexibility, suitable band gap, low cost, and the abundance of the resources they require. An all-organic composite photocatalytic nanomaterial C3 N4 /perylene-3,4,9,10-tetracarboxylic diimide (PDINH) heterostructure is created through recrystallization of PDINH on the surface of C3 N4 in situ, resulting in enhanced photocatalytic efficiency due to the formation of a basal heterostructure. The absorption spectrum of this composite structure can be extended from ultraviolet to near-infrared light (750 nm), enhancing the photocatalytic effect to produce more reactive oxygen species, which have an excellent inactivation effect on both Gram-negative and positive bacteria, while demonstrating negligible toxicity to normal tissue cells. An efficient promotion of infectious wound regeneration in mice with Staphylococcus aureus infected dermal wounds is demonstrated. This all-organic heterostructure shows great promise for use in wound disinfection.


Assuntos
Antibacterianos/química , Imidas/química , Nitrilos/química , Perileno/análogos & derivados , Fotoquimioterapia/métodos , Fármacos Fotossensibilizantes/química , Semicondutores , Animais , Antibacterianos/uso terapêutico , Antibacterianos/toxicidade , Catálise , Sobrevivência Celular , Escherichia coli/efeitos dos fármacos , Feminino , Luz , Camundongos , Camundongos Endogâmicos BALB C , Células NIH 3T3 , Nanoestruturas/química , Nitrilos/uso terapêutico , Nitrilos/toxicidade , Perileno/química , Fármacos Fotossensibilizantes/uso terapêutico , Fármacos Fotossensibilizantes/toxicidade , Porfirinas/uso terapêutico , Porfirinas/toxicidade , Espécies Reativas de Oxigênio/metabolismo , Staphylococcus aureus/efeitos dos fármacos , Cicatrização , Infecção dos Ferimentos/tratamento farmacológico , Infecção dos Ferimentos/microbiologia
13.
Chemistry ; 25(47): 11085-11097, 2019 Aug 22.
Artigo em Inglês | MEDLINE | ID: mdl-31219221

RESUMO

Naphthalene diimide (NDI) dyads exhibiting a different substitution pattern and linker length have been synthesised and evaluated as G-quadruplex (G4) ligands, by investigating their cytotoxicity in selected cell lines. The dyads with the long C7 linker exhibit extremely low IC50 values, below 10 nm, on different cancer cell lines. Contrary, the dyads with the shorter C4 linker were much less effective, with IC values increasing up to 1 µm. Among the three dyads with the longest linker, small differences in the IC50 values emerge, suggesting that the linker length plays a more important role than the substitution pattern. We have further shown that the dyads are able to induce cellular DNA damage response, which is not limited to the telomeric regions and is likely the origin of their cytotoxicity. Both absorption titration and dynamic light scattering of the most cytotoxic dyads in the presence of hTel22 highlight their ability to induce effective G4 aggregation, acting as non-covalent cross-linking agents.


Assuntos
Dano ao DNA/efeitos dos fármacos , Reparo do DNA/efeitos dos fármacos , Quadruplex G , Imidas/farmacologia , Naftalenos/farmacologia , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Imidas/síntese química , Imidas/química , Ligantes , Metáfase/efeitos dos fármacos , Microscopia de Fluorescência , Naftalenos/síntese química , Naftalenos/química , Proteínas Proto-Oncogênicas c-kit/genética , Proteínas Proto-Oncogênicas c-kit/metabolismo , Proteínas Proto-Oncogênicas c-myc/genética , Proteínas Proto-Oncogênicas c-myc/metabolismo , Telômero/efeitos dos fármacos , Telômero/metabolismo
14.
Chemistry ; 25(44): 10464-10471, 2019 Aug 06.
Artigo em Inglês | MEDLINE | ID: mdl-31111971

RESUMO

Programmable assembly of biomolecules is a fast growing research area that aims to emulate nature's elegance in creating numerous hierarchical self-assembled structures, which are responsible for unimaginably difficult biological functions. Protein assembly is a particularly challenging task, owing to their structural diversity, conformational heterogeneity, and high molecular weight. This article reveals the ability of a supramolecular structure-directing unit (SSDU) to regulate the entropically favourable supramolecular assembly of a covalently conjugated protein (bovine serum albumin (BSA)) to produce well-defined protein-decorated micelles with remarkably high thermal stability, suppression of the thermal denaturation of the protein, and retention of enzymatic activity. Furthermore, a SSDU-appended thermo-responsive poly(N-isopropylacrylamide) (PNIPAM) co-assembles with the SSDU-BSA conjugate because, in both cases, assembly was primarily driven by specific molecular recognition between the SSDUs. However, the resulting supramolecular protein-polymer conjugate exhibits distinctly different polymersome structure to that of the micellar particle produced by the protein-SSDU conjugate. In this case, the enzymatic activity can be significantly suppressed above the lower critical solution temperature of supramolecularly conjugated PNIPAM, possibly due to collapse of the de-solvated polymer chains on the protein surface.


Assuntos
Resinas Acrílicas/química , Soroalbumina Bovina/química , Imidas/química , Micelas , Nanopartículas/química , Naftalenos/química , Temperatura Ambiente , Termodinâmica
15.
Molecules ; 24(8)2019 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-30991655

RESUMO

Four pairs of amino acid-functionalized naphthalenediimide enantiomers (d- and l-lysine derived NDIs) were screened toward G-quadruplex forming sequences in telomeres (h-TELO) and oncogene promoters: c-KIT1, c-KIT2, k-RAS and BCL-2. This is the first study to address the effect of point chirality toward G-quadruplex DNA stabilization using purely small organic molecules. Enantioselective behavior toward the majority of ligands was observed, particularly in the case of parallel conformations of c-KIT2 and k-RAS. Additionally, Nε-Boc-l-Lys-NDI and Nε-Boc-d-Lys-NDI discriminate between quadruplexes with parallel and hybrid topologies, which has not previously been observed with enantiomeric ligands.


Assuntos
DNA/química , Quadruplex G , Imidas/química , Naftalenos/química , Telômero/química , Humanos , Oncogenes
16.
ACS Appl Mater Interfaces ; 11(18): 17079-17089, 2019 May 08.
Artigo em Inglês | MEDLINE | ID: mdl-30978000

RESUMO

Perylene bisimide derivatives show peculiar physical chemical features, such as a highly conjugated system, high extinction coefficients and elevated fluorescence quantum yields, making them suitable for the development of optical sensors of compounds of interest. In particular, they are characterized by the tendency to aggregate into π-π stacked supramolecular structures. In this contribution, the behavior of the PBI derivative N, N'-bis(2-(trimethylammonium)ethylene)perylene bisimide dichloride was investigated both in aqueous solution and on solid support. The electronic communication between PBI aggregates and biogenic amines was exploited in order to discriminate aromatic amines down to subnanomolar concentrations by observing PBI fluorescence variations in the presence of various amines and at different concentrations. The experimental findings were corroborated by density functional theory calculations. In particular, phenylethylamine and tyramine were demonstrated to be selectively detected down to 10-10 M concentration. Then, in order to develop a surface plasmon resonance (SPR) device, PBI was deposited onto a SPR support by means of the layer-by-layer method. PBI was deposited in the aggregated form and was demonstrated to preserve the capability to discriminate, selectively and with an outstanding analytical sensitivity, tyramine in the vapor phase and even if mixed with other aromatic amines.


Assuntos
Aminas Biogênicas/isolamento & purificação , Técnicas Biossensoriais , Fenetilaminas/isolamento & purificação , Tiramina/isolamento & purificação , Aminas Biogênicas/química , Corantes/química , Fluorescência , Imidas/química , Perileno/análogos & derivados , Perileno/química , Fenetilaminas/química , Pontos Quânticos/química , Soluções/química , Ressonância de Plasmônio de Superfície , Tiramina/química , Água/química
17.
Molecules ; 24(6)2019 Mar 22.
Artigo em Inglês | MEDLINE | ID: mdl-30909483

RESUMO

An oxidative 3-amination of indole derivatives using hypervalent iodine(III) and bissulfonimides, which proceeds via the formation of indolyl(aryl)iodonium imides, was developed. This reaction was followed by an indole-selective copper-catalyzed oxidative C⁻N coupling reaction to obtain 3-amino indole derivatives as single regioisomers. o-Alkoxy(diacetoxyiodo)arenes showed higher reactivity in the reaction than o-alkyl(diacetoxyiodo)arenes, efficiently promoting the formation of indolyl(aryl)iodonium imides in the first step.


Assuntos
Cobre/química , Imidas/química , Indóis/química , Iodo/química , Oxirredução , Aminação , Catálise , Solventes , Análise Espectral
18.
Chem Commun (Camb) ; 55(25): 3658-3661, 2019 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-30855054

RESUMO

Due to the host-guest interaction between cucurbit[10]uril and perylenebisdiimide (PDI) derivatives, DNA-PDI conjugates can achieve morphological shifting from spherical micelles to two-dimensional nanosheets. The competitive binding between the guest 3,5-dimethyl-1-adamantanamine hydrochloride and PDI units induces the reversibility. The 2D nanosheets can act as addressable templates to organize the functional molecules through DNA hybridization.


Assuntos
DNA/química , Imidas/química , Difusão Dinâmica da Luz , Microscopia de Força Atômica , Microscopia Eletrônica de Transmissão , Nanoestruturas/química , Perileno/química , Espectrometria de Fluorescência
19.
Sensors (Basel) ; 19(4)2019 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-30781357

RESUMO

To meet the application requirements of curvature measurement for soft biomedical robotics and flexible morphing wings of aircraft, the optical fiber Bragg grating (FBG) shape sensor for soft robots and flexible morphing wing was implemented. This optical FBG is embedded in polyimide film and then fixed in the body of a soft robot and morphing wing. However, a lack of analysis on the embedded depth of FBG sensors in polyimide film and its sensitivity greatly limits their application potential. Herein, the relationship between the embedded depth of the FBG sensor in polyimide film and its sensitivity and stability are investigated. The sensing principle and structural design of the FBG sensor embedded in polyimide film are introduced; the bending curvatures of the FBG sensor and its wavelength shift in polyimide film are studied; and the relationship between the sensitivity, stability, and embedded depth of these sensors are verified experimentally. The results showed that wavelength shift and curvature have a linear relationship. With the sensor's curvature ranging from 0 m-1 to 30 m-1, their maximum sensitivity is 50.65 pm/m-1, and their minimum sensitivity is 1.96 pm/m-1. The designed FBG sensor embedded in polyimide films shows good consistency in repeated experiments for soft actuator and morphing wing measurement; the FBG sensing method therefore has potential for real applications in shape monitoring in the fields of soft robotics and the flexible morphing wings of aircraft.


Assuntos
Técnicas Biossensoriais/métodos , Tecnologia de Fibra Óptica/métodos , Imidas/química , Robótica/métodos , Fibras Ópticas
20.
Chemistry ; 25(28): 6928-6940, 2019 May 17.
Artigo em Inglês | MEDLINE | ID: mdl-30807667

RESUMO

Two novel solid reagents-1-sulfonimidoyl- and 1-sulfamimidoyl-3-methylimidazolium derivatives-for the synthesis of sulfonimidamides and imidosulfuric diamides, respectively, were developed. It is shown that these reagents are very effective in substitution reactions with various N- and O-nucleophiles; therefore, they significantly extend the accessibility to the chemical space covered by organosulfur(VI) compounds with S=N bonds. In addition, previously unknown imidosulfuric diamides with free imino nitrogen groups were prepared, and their physical and chemical properties were characterized (including molecular geometry, pKa , Log P, microsomal stability, and reactivity towards typical electrophiles). Similar to other organosulfur(VI) derivatives with S=N bonds, these compounds can be considered as promising bioisosteres of amides, ureas, or sulfonamides.


Assuntos
Diamida/síntese química , Imidas/síntese química , Sulfonamidas/síntese química , Compostos de Enxofre/síntese química , Animais , Técnicas de Química Sintética/métodos , Diamida/química , Diamida/metabolismo , Imidas/química , Imidas/metabolismo , Indicadores e Reagentes , Camundongos , Microssomos/metabolismo , Modelos Moleculares , Sulfonamidas/química , Sulfonamidas/metabolismo , Compostos de Enxofre/química , Compostos de Enxofre/metabolismo , Difração de Raios X
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