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1.
Biosensors (Basel) ; 11(8)2021 Aug 03.
Artigo em Inglês | MEDLINE | ID: mdl-34436063

RESUMO

The composition and content of fatty acids are critical indicators to identify the quality of edible oils. This study was undertaken to establish a rapid determination method for quality detection of edible oils based on quantitative analysis of palmitic acid, stearic acid, arachidic acid, and behenic acid. Seven kinds of oils were measured to obtain Vis-NIR spectra. Multivariate methods combined with pretreatment methods were adopted to establish quantitative analysis models for the four fatty acids. The model of support vector machine (SVM) with standard normal variate (SNV) pretreatment showed the best predictive performance for the four fatty acids. For the palmitic acid, the determination coefficient of prediction (RP2) was 0.9504 and the root mean square error of prediction (RMSEP) was 0.8181. For the stearic acid, RP2 and RMSEP were 0.9636 and 0.2965. In the prediction of arachidic acid, RP2 and RMSEP were 0.9576 and 0.0577. In the prediction of behenic acid, the RP2 and RMSEP were 0.9521 and 0.1486. Furthermore, the effective wavelengths selected by successive projections algorithm (SPA) were useful for establishing simplified prediction models. The results demonstrate that Vis-NIR spectroscopy combined with multivariate methods can provide a rapid and accurate approach for fatty acids detection of edible oils.

2.
Acta Crystallogr E Crystallogr Commun ; 77(Pt 6): 629-633, 2021 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-34164141

RESUMO

The title compound, (C12H15N2)2[ZnCl4], is a salt with two symmetrically independent, essentially planar heterocyclic cations and a slightly distorted tetra-hedral chloro-zincate dianion. N-H⋯Cl hydrogen bonds link these ionic constituents into a discrete aggregate, which comprises one formula unit. The effect of hydrogen bonding is reflected in the minor distortions of the [ZnCl4]2- moiety: distances between the cation and chlorido ligands engaged in classical hydrogen bonds are significantly longer than the others. Secondary inter-actions comprise C-H⋯π hydrogen bonding and weak π-π stacking. A Hirshfeld surface analysis indicates that the most abundant contacts in packing stem from H⋯H (47.8%) and Cl⋯H/H⋯Cl (29.3%) inter-actions.

3.
ACS Cent Sci ; 7(5): 768-780, 2021 May 26.
Artigo em Inglês | MEDLINE | ID: mdl-34079895

RESUMO

Raman scattering provides stable narrow-banded signals that potentially allow for multicolor microscopic imaging. The major obstacle for the applications of Raman spectroscopy and microscopy is the small cross section of Raman scattering that results in low sensitivity. Here, we report a new concept of azo-enhanced Raman scattering (AERS) by designing the intrinsic molecular structures using resonance Raman and concomitant fluorescence quenching strategies. Based on the selection of vibrational modes and the enhancing unit of azobenzenes, we obtained a library of AERS molecules with specific Raman signals in the fingerprint and silent frequency regions. The spectral characterization and molecular simulation revealed that the azobenzene unit conjugated to the vibrational modes significantly enhanced Raman signals due to the mechanism of extending the conjugation system, coupling the electronic-vibrational transitions, and improving the symmetry of vibrational modes. The nonradiative decay of azobenzene from the excited state quenched the commitment fluorescence, thus providing a clean background for identifying Raman scattering. The most sensitive AERS molecules produced Raman signals of more than 4 orders of magnitude compared to 5-ethynyl-2'-deoxyuridine (EdU). In addition, a frequency tunability of 10 distinct Raman bands was achieved by selecting different types of vibrational modes. This methodology of AERS allows for designing small-molecule Raman probes to visualize various entities in complex systems by multicolor spontaneous Raman imaging. It will open new prospects to explore innovative applications of AERS in interdisciplinary research fields.

4.
Dalton Trans ; 50(23): 8154-8166, 2021 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-34028483

RESUMO

The synthesis of di- and tritopic gold(i) metallaligands of the type [(Au4-py)2(µ2-diphosphane)] (diphosphane = bis(diphenylphosphanyl)isopropane or dppip (1), 1,2-bis(diphenylphosphanyl)ethane or dppe (2), 1,3-bis(diphenylphosphanyl)propane or dppp (3) and 1,4-bis(diphenylphosphanyl)butane or dppb (4)) and [(Au4-py)3(µ3-triphosphane)] (triphosphane = 1,1,1-tris(diphenylphosphanylmethyl)ethane or triphos (5) and 1,3,5-tris(diphenylphosphanyl)benzene or triphosph (6)) from [(AuCl)2(µ2-diphosphane)] or [(AuCl)3(µ3-triphosphane)] and 4-pyridylboronic acid in the presence of Cs2CO3 has been conducted. Interestingly, when [(AuCl)2(µ2-dppm)] (dppm = bis(diphenylphosphanyl)methane) was used as a starting material, the cyclic tetranuclear gold(i) compound [(Au4-py)2(CH)2{µ2-Au(PPh2)2}2] (I) was obtained instead. All the products have been characterized by IR and multinuclear NMR spectroscopy, mass spectrometry and elemental analysis and in the case of 1, 3, 5 and I by X-ray crystallography, which showed the presence of aurophilic interactions in all of them. The obtained metallaligands have been used as building blocks in self-assembly reactions with cis-blocked palladium or platinum acceptor moieties producing [2 + 2] metallamacrocycles or trigonal bipyramidal (TBP) [2 + 3] metallacages in good yields. The photophysical properties of both the metallaligands and the corresponding assemblies have been investigated.

5.
Chemistry ; 27(38): 9814-9819, 2021 Jul 07.
Artigo em Inglês | MEDLINE | ID: mdl-33834537

RESUMO

Based on the DFT-level-calculated molecular volume (Vmol ) of pyrrole and its liquid density, pyrrole manifests the highest liquid density coefficient LDc (defined as [Vmol ×density ×0.6023]/FW) value of 0.7. Normal liquids have LDc <0.63. This very high LDc is due to the strong N-H⋅⋅⋅π interactions in solution, and hence pyrrole can be considered to be a pseudo-crystalline liquid. When trapped inside the confined space of a crystalline sponge, a reorientation of the N-H⋅⋅⋅π interaction is observed leading to specific cyclic N-H⋅⋅⋅π tetramers and N-H⋅⋅⋅π dimers, as verified by single-crystal X-ray crystallographic and computational methods. These tetramers are of the same size as four pyrrole molecules in the solid-state of pyrrole, yet the cyclic N-H⋅⋅⋅π intermolecular interactions are circularly oriented instead of being in the linear zigzag structure found in the X-ray structure of a solid pyrrole. The confinement thus acts as an external driving force for tetramer formation.


Assuntos
Pirróis , Cristalografia por Raios X , Modelos Moleculares
6.
Ear Nose Throat J ; : 1455613211000292, 2021 Mar 18.
Artigo em Inglês | MEDLINE | ID: mdl-33734878

RESUMO

Facial nerve schwannoma (FNS) is a benign, slow-growing schwannoma that originates from Schwann cells. Facial nerve schwannoma is the most common tumor of the facial nerve but rare and only accounts for 0.15% to 0.8% of intracranial neurinomas. It may be manifested as asymmetric hearing loss, facial palsy, and hemifacial spasm. A 56-year-old woman was transferred to our department, because of pain behind the right ear and spasm of the right lateral muscle for more than 2 years and pulsatile tinnitus for half a year. Based on the preoperative medical history, physical signs, and auxiliary examination, it was diagnosed with jugular foramen (JF) space-occupying lesion. We removed the tumor through the infratemporal fossa type A approach and found that the tumor originated from the facial nerve. After the tumor resection, sural nerve transplantation was performed. The patient demonstrated postoperative facial palsy (House-Brackman grade VI) and was smoothly discharged after good recovery. Facial nerve schwannoma rarely invades the JF, and the most common tumor in the JF is the glomus jugular tumor, followed by the posterior cranial schwannoma. They have common symptoms, making it difficult to obtain a correct diagnosis. Clinical data, medical history, and auxiliary examinations should be carefully analyzed to avoid misdiagnosis or mistreatment. Infratemporal fossa type A approach is an effective method for treating FNS of JF.

7.
Chemistry ; 27(15): 5011-5018, 2021 Mar 12.
Artigo em Inglês | MEDLINE | ID: mdl-33438786

RESUMO

A 3D Co-based metal-organic framework (Co-MOF) with two kinds of large pores filled by free Co2+ ions and ligands was synthesized and characterized. To expand the MOF structure and conductivity, the free Co2+ ions and ligands were exchanged by conductive ionic liquid EtpyBr and photosensitive AgNO3 through single crystal-to-single crystal transformation, which produced structure-changed 3D MOFs Co-MOF-Br and Co-Ag-MOF, which were characterized by single-crystal X-ray diffraction. Incorporating small quantities of doped polyaniline (PANI) with redox activity into the pores could further tune the stability and conductivity of the three MOFs. The PANI/MOFs all show outstanding electrical conductivity (≈10-2  S cm-1 ), and PANI/Co-MOF-Br has the largest p-type Seebeck coefficient of 66.6 µV K-1 . PANI/Co-MOF-Br and PANI/Co-Ag-MOF have 4 and 15 times higher photocurrent density compared with PANI/Co-MOF, respectively. This work sheds light on the design of advanced electrically conductive 3D MOFs.

8.
ACS Appl Mater Interfaces ; 12(41): 45968-45975, 2020 Oct 14.
Artigo em Inglês | MEDLINE | ID: mdl-32930562

RESUMO

The spin-spin interactions between unpaired electrons in organic (poly)radicals, especially nitroxides, are largely investigated and are of crucial importance for their applications in areas such as organic magnetism, molecular charge transfer, or multiple spin labeling in structural biology. Recently, 2,2,6,6-tetramethylpiperidinyloxyl and polymers functionalized with nitroxides have been described as successful redox mediators in several electrochemical applications; however, the study of spin-spin interaction effect in such an area is absent. This communication reports the preparation of a novel family of discrete polynitroxide molecules, with the same number of radical units but different arrangements to study the effect of intramolecular spin-spin interactions on their electrochemical potential and their use as oxidation redox mediators in a Li-oxygen battery. We find that the intensity of interactions, as measured by the d1/d electron paramagnetic resonance parameter, progressively lowers the reduction potential. This allows us to tune the charging potential of the battery, optimizing its energy efficiency.

9.
J Org Chem ; 85(9): 5884-5894, 2020 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-32174116

RESUMO

Cethyl-2-methylresorcinarene (A), pyridine (B), and a set of 10 carboxylic acids (Cn) associate to form A·B·Cn ternary assemblies with 1:1:1 stoichiometry, representing a useful class of ternary systems where the guest mediates complex formation between the host and a third component. Although individually weak in solution, the combined strength of the multiple noncovalent interactions organizes the complexes even in a highly hydrogen-bond competing methanol solution, as explored by both experimental and computational methods. The interactions between A·B and Cn are dependent on the pKa values of carboxylic acids. The weak interactions between A and C further reinforce the interactions between A and B, demonstrating positive cooperativity. Our results reveal that the two-component system such as that formed by A and B can form the basis for the development of specific sensors for the molecular recognition of carboxylic acids.

10.
Spectrochim Acta A Mol Biomol Spectrosc ; 230: 118005, 2020 Apr 05.
Artigo em Inglês | MEDLINE | ID: mdl-31951866

RESUMO

High economic returns induce the continuous occurrence of meat adulteration. In this study, visible/near-infrared (Vis/NIR) reflectance spectroscopy with multivariate methods was used for the rapid detection of adulteration in minced beef. First, the reflectance spectra of different adulterated minced beef samples were measured at 350-2500 nm. Standardization and Savitzky-Golay (SG) smoothing were applied to reduce spectral interference and noise. Then, support vector machine (SVM), random forest (RF), partial least squares regression (PLSR), and deep convolutional neural network (DCNN) were adopted for adulteration type identification and level prediction. Moreover, principal component analysis (PCA), locally linear embedding (LLE), subwindow permutation analysis (SPA), and competitive adaptive reweighted sampling (CARS) were performed to eliminate redundant information. SG smoothing performed better on interference reduction. DCNN and PCA identified adulteration type with the accuracy above 99%. In adulteration level prediction, the RF with spectra of important wavelengths selected by CARS provided optimal performance for beef adulterated with pork, and coefficient of determination of prediction (R2P) and the root mean square error of prediction (RMSEP) were 0.973 and 2.145. The best prediction for beef adulterated with beef heart was obtained using PLSR and CARS with R2P of 0.960 and RMSEP of 2.758. Accordingly, Vis/NIR reflectance spectroscopy coupled with multivariate methods can provide the rapid and accurate detection of adulterated minced beef.


Assuntos
Contaminação de Alimentos/análise , Carne/análise , Redes Neurais de Computação , Carne Vermelha/análise , Espectroscopia de Luz Próxima ao Infravermelho/métodos , Máquina de Vetores de Suporte , Animais , Bovinos , Análise de Componente Principal
11.
Ying Yong Sheng Tai Xue Bao ; 31(12): 4235-4242, 2020 Dec.
Artigo em Chinês | MEDLINE | ID: mdl-33393262

RESUMO

To investigate the physiological response of IAA (indoleacetic acid) to Trichosanthes kirilowii under aluminum stress and the mitigation of DNA damage, the effects of IAA (0, 10, 25, 50, 75 µmol·L-1 denoted by I0, I10, I25, I50 and I75, respectively) on antioxidant enzyme activity, malondialdehyde (MDA), photosynthetic characteristics, root activity, chlorophyll content and DNA damage of two varieties of T. kirilowii under 300 and 800 µmol·L-1 aluminum environment (denoted by Al300 and Al800, respectively) were examined in hydroponic culture experiments with Hebei Anguo (aluminium tolerant variety) and Zhejiang Puyang Trichosanthes kirilowii (aluminum sensitive variety). The results showed that the activities of superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT), photosynthesis ability, and root activity of both varieties were inhibited to different degrees by aluminum stress, MDA content was significantly increased, and DNA damage was aggravated. The maximum increase of SOD, CAT and POD activities in Anguo and Puyang T. kirilowii under aluminum stress by IAA application were 15.0%, 31.2%, 72.3% and 13.8%, 26.9%, 26.4%, respectively, chlorophyll content increased by 49.9% and 17.9%, MDA accumulation decreased by 39.2% and 22.4% and fluorescence parameters were significantly improved. The treatment of 25 µmol·L-1 IAA significantly increased root activity by 159.1% and 90.9%, while 50 µmol·L-1 IAA effectively slowed the DNA tailing phenomenon in roots, with the product (OTM) value of tail DNA percentage content and tail moment being decreased by 27.6%. 10-50 µmol·L-1 IAA could effectively improve the physiological activity of T. kirilowii under aluminum stress and slow the degree of DNA damage. The tolerance of Anguo variety to aluminum stress was stronger than that of Puyang variety.


Assuntos
Trichosanthes , Alumínio , Catalase , Dano ao DNA , Plântula , Estresse Fisiológico , Superóxido Dismutase
12.
Inorg Chem ; 58(18): 12132-12145, 2019 Sep 16.
Artigo em Inglês | MEDLINE | ID: mdl-31464135

RESUMO

Four cationic iridium complexes with 5-phenyl-1H-1,2,4-triazole (phtz) type cyclometalating ligands (C^N) and different ancillary ligands (N^N), namely, [Ir(dphtz)2(bpy)]PF6 (1), [Ir(dphtz)2(pzpy)]PF6 (2), [Ir(Mephtz)2(pzpy)]PF6 (3), and [Ir(Mephtz)2(dma-pzpy)]PF6 (4), have been designed, synthesized, and fully characterized (dphtz = 1-(2,6-dimethylphenyl)-3-methyl-5-phenyl-1H-1,2,4-triazole, Mephtz = 1,3-dimethyl-5-phenyl-1H-1,2,4-triazole; bpy = 2,2'-bipyridine, pzpy = 2-(1H-pyrazol-1-yl)pyridine, dma-pzpy = 4-dimethylamino-2-(1H-pyrazol-1-yl) pyridine). In solution, complex 1 emits efficient yellow light (λmax = 547 nm), which is blue-shifted by nearly 40 nm (or by 1187 cm-1) compared with that from the archetypal complex [Ir(ppy)2(bpy)]PF6 (Hppy = 2-phenylpyridine), owing to the stabilization of the highest occupied molecular orbital by the phtz-type C^N ligand. In the lightly doped rigid films, complex 1 emits green light with a high luminescent efficiency of 0.89. Although complexes 2-4 with electron-rich N^N ligands are weakly emissive or nearly nonemissive in the solution, they emit relatively strong deep-blue light peaked around 435 and 461 nm in the lightly doped films, which is among the bluest reported for cationic iridium complexes. Theoretical calculations reveal that for complex 1, the emission always comes from the charge-transfer (CT) (Ir/C^N → N^N) state; for complexes 2 and 3, the 3CT and C^N-centered 3π-π* states lie close in energy and the emission could originate from either or both of them; for complex 4, the emission comes predominantly from the C^N-centered 3π-π* state. For blue-emitting complexes 2-4, metal-centered states play an active role in the nonradiative deactivation of the emitting triplet states. Solid-state light-emitting electrochemical cells (LECs) based on complexes 1-3 show yellow-green, blue, and blue-green electroluminescence, respectively, with the yellow-green LEC affording a peak current efficiency of 21.5 cd A-1.

13.
Angew Chem Int Ed Engl ; 58(43): 15273-15277, 2019 Oct 21.
Artigo em Inglês | MEDLINE | ID: mdl-31436902

RESUMO

The formation of well-defined finite-sized aggregates represents an attractive goal in supramolecular chemistry. In particular, construction of discrete π-stacked dye assemblies remains a challenge. Reported here is the design and synthesis of a novel type of discrete π-stacked aggregate from two comparable perylenediimide (PDI) dyads (PEP and PBP). The criss-cross PEP-PBP dimers in solution and (PBP-PEP)-(PEP-PBP) tetramers in the solid state are well elucidated using single-crystal X-ray diffraction, dynamic light scattering, and diffusion-ordered NMR spectroscopy. Extensive π-π stacking between the PDI units of PEP and PBP as well as repulsive interactions of swallow-tailed alkyl substituents are responsible for the selective formation of discrete dimer and tetramer stacks. Our results reveal a new approach to preparing discrete π stacks that are appealing for making assemblies with well-defined optoelectronic properties.

14.
Molecules ; 24(15)2019 Jul 29.
Artigo em Inglês | MEDLINE | ID: mdl-31362371

RESUMO

Phytochemical investigations of ethanol root bark and stem bark extracts of Cleistochlamys kirkii (Benth.) Oliv. (Annonaceae) yielded a new benzopyranyl cadinane-type sesquiterpene (cleistonol, 1) alongside 12 known compounds (2-13). The structures of the isolated compounds were established from NMR spectroscopic and mass spectrometric analyses. Structures of compounds 5 and 10 were further confirmed by single crystal X-ray crystallographic analyses, which also established their absolute stereochemical configuration. The ethanolic crude extract of C. kirkii root bark gave 72% inhibition against the chloroquine-sensitive 3D7-strain malaria parasite Plasmodium falciparum at 0.01 µg/mL. The isolated metabolites dichamanetin, (E)-acetylmelodorinol, and cleistenolide showed IC50 = 9.3, 7.6 and 15.2 µM, respectively, against P. falciparum 3D7. Both the crude extract and the isolated compounds exhibited cytotoxicity against the triple-negative, aggressive breast cancer cell line, MDA-MB-231, with IC50 = 42.0 µg/mL (crude extract) and 9.6-30.7 µM (isolated compounds). Our findings demonstrate the potential applicability of C. kirkii as a source of antimalarial and anticancer agents.


Assuntos
Annonaceae/química , Antimaláricos/química , Antimaláricos/farmacologia , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Sesquiterpenos Policíclicos/química , Sesquiterpenos Policíclicos/farmacologia , Annonaceae/metabolismo , Humanos , Malária/tratamento farmacológico , Conformação Molecular , Estrutura Molecular , Testes de Sensibilidade Parasitária , Análise Espectral
15.
Angew Chem Int Ed Engl ; 58(38): 13375-13379, 2019 Sep 16.
Artigo em Inglês | MEDLINE | ID: mdl-31293048

RESUMO

Chiral catalysts tolerating photochemical reactions are in great demand for the vast development of visible-light-induced asymmetric synthesis. Now, chiral octahedral complexes based on earth-abundant metal and chiral N4 ligands are reported. One well-defined chiral CoII -complex is shown to be an efficient catalyst in the visible-light-induced conjugated addition of enones by alkyl and acyl radicals, providing synthetically valued chiral ketones and 1,4-dicarbonyls in 47->99 % yields with up to 97:3 e.r.

16.
Chem Commun (Camb) ; 55(54): 7768-7771, 2019 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-31210219

RESUMO

A hybrid macrocycle was synthesized by combining the repeat units in oxatub[4]arene and zorb[4]arene, and its recognition behavior and conformational analysis were studied. Three structurally similar and conformationally adaptive macrocycles show different guest-binding selectivities and preferences even in a complex mixture containing three macrocycles and three guests.

17.
Beilstein J Org Chem ; 15: 947-954, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31164931

RESUMO

Single crystal X-ray structures of halogen-bonded assemblies formed between host N-hexylammonium resorcinarene bromide (1) or N-cyclohexylammonium resorcinarene chloride (2), and 1,4-diiodooctafluorobutane and accompanying small solvent guests (methanol, acetonitrile and water) are presented. The guests' inclusion affects the geometry of the cavity of the receptors 1 and 2, while the divalent halogen bond donor 1,4-diiodooctafluorobutane determines the overall nature of the halogen bond assembly. The crystal lattice of 1 contains two structurally different dimeric assemblies A and B, formally resulting in the mixture of a capsular dimer and a dimeric pseudo-capsule. 1H and 19F NMR analyses supports the existence of these halogen-bonded complexes and enhanced guest inclusion in solution.

18.
Inorg Chem ; 58(12): 7649-7652, 2019 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-31135141

RESUMO

Host-guest interactions are the key to the supramolecular chemistry and the further application of the receptors to study the structural details of the small guest molecules. Crystalline sponges as a kind of supramolecular receptor need to be investigated in terms of the binding ability with the guests. We found in this work that one guest with σ-hole donors and another with electron-donating species were separately entrapped in two distinct channels of the host framework via the crystalline sponge method. Halogen bonding and weak hydrogen bonding were detected between the host and the two guests, respectively. The ability of the crystalline sponge to absorb and sort guests of different types was unambiguously confirmed by X-ray crystallography.

19.
Chemistry ; 25(31): 7485-7488, 2019 Jun 04.
Artigo em Inglês | MEDLINE | ID: mdl-30994210

RESUMO

Co-crystallizing iodine with a simple dicationic salt (1,8-diammoniumoctane chloride) results in the clathration of the iodine (I2 ) molecules inside trigonal and hexagonal helical channels of the crystal lattice with 72 wt % overall I2 loading. The I2 inside the bigger trigonal channel forms a I-I⋅⋅⋅I-I⋅⋅⋅I-I halogen-bonded infinite helical chain, while the I2 in the smaller hexagonal channel is disordered. In both channels the I2 interaction with the channel wall happens through I-I⋅⋅⋅Cl- halogen bonds. The helical channels in the crystal lattice are constructed via the strong charge-assisted H2 N+ H⋅⋅⋅Cl- hydrogen bonds between the dications and the chloride anions. The structure shows a marked similarity with the well-known starch-I2 system, and thus may provide insight for the yet unresolved structure of the I2 in the helical starch channel.

20.
Acta Crystallogr B Struct Sci Cryst Eng Mater ; 75(Pt 6): 987-993, 2019 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-32830678

RESUMO

The second polymorph of the compound 2,4,6-tris(4-pyridyl)-1,3,5-triazine (TPT) is reported, TPT-II, which crystallizes in space group I2/a. Its higher density and more efficient space filling indicate the lower entropy of TPT-II, while its slightly lower melting point indicates its weaker intermolecular interactions. The conditions of the crystallization experiments for TPT-I and TPT-II are the dominant factors that determine the final crystalline products. The crystals of TPT-II are long needles. They exhibit bending behaviour along the crystallographic b direction when a mechanical force is imposed perpendicular to it, and regain their original shape after the external stress is removed. The elasticity of the single crystals is interpreted in terms of intermolecular interactions and an energy framework analysis.

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