The chirality-induced spin selectivity (CISS) effect has garnered significant interest in the field of molecular spintronics due to its potential to create spin-polarized electrons without the need for a magnet. Recent studies devoted to CISS effects in various chiral materials demonstrate exciting prospects for spintronics, chiral recognition, and quantum information applications. Several experimental studies have confirmed the applicability of chiral molecules in spin-filtering properties, influencing spin-polarized electron transport and photoemission.
View Article and Find Full Text PDFThe Chiral-Induced Spin Selectivity (CISS) effect has emerged as a fascinating phenomenon within the realm of electron's spin manipulation, showcasing a unique interplay between electron's spin and molecular chirality. Subsequent to its discovery, researchers have been actively involved in exploring the new chiral molecules as effective spin filters. In the realm of observing the CISS effect, the conventional approach has mandated the utilization of two distinct enantiomers of chiral molecules.
View Article and Find Full Text PDFChirality has been identified as a crucial component in achieving high spin selectivity in organic polymers and π-conjugated molecules. In particular, chiral polymers and supramolecular structures have emerged as promising candidates for spin filtering due to the chirality-induced spin selectivity (CISS) effect. However, the CISS effect in supramolecular systems has not been extensively investigated, despite its potential for applications in spintronics.
View Article and Find Full Text PDFThe cooperativity in artificial self-assembling systems can be enhanced to expand their applications and redesign their properties. Recently, chiral molecules have garnered renewed attention due to their potential as highly efficient spin filters through the chiral-induced spin selectivity (CISS) effect. However, the potential of asymmetric building blocks based on chiral perylene diimides (PDIs) self-assembled materials to generate a spin-polarized current is still not widely acknowledged.
View Article and Find Full Text PDFBackground And Aims: Magnesium sulphate and zinc sulphate have been reported to attenuate postoperative sore throat (POST). The study aims to compare the effect of preoperative magnesium sulphate and zinc sulphate gargle on the incidence and severity of POST following endotracheal intubation within 24 h.
Methods: After ethics committee approval, 132 patients were randomly allocated to three groups (M, Z and D).
Metal-organic Co(II)-phenylalanine crystals were studied and were found to possess magnetic properties and long-range spin transport. Magnetic measurements confirmed that in the crystals there are antiferromagnetic interactions between Co(II) and the lattice. The metal-organic crystals (MOCs) also present the chirality-induced spin selectivity (CISS) effect at room temperature.
View Article and Find Full Text PDFACS Appl Mater Interfaces
February 2023
Understanding the stability and degradation of organic light-emitting diodes (OLEDs) under working conditions is a significant area of research for developing more effective OLEDs and further improving their performance. However, studies of degradation processes by in situ noninvasive methods have not been adequately developed. In this work, tris-(8-hydroxyquinolino) aluminum (Alq)-based OLED degradation processes have been analyzed through the investigation of the device dispersive magneto-electroluminescence (MEL()) response measured at room temperature.
View Article and Find Full Text PDFWe describe the spin polarization-induced chirogenic electropolymerization of achiral 2-vinylpyridine, which forms a layer of enantioenhanced isotactic polymer on the electrode. The product formed is enantioenriched in asymmetric carbon polymer. To confirm the chirality of the polymer film formed on the electrode, we also measured its electron spin polarization properties as a function of its thickness.
View Article and Find Full Text PDF(Rs), the causative agent of devastating wilt disease in several major and minor economic crops, is considered one of the most destructive bacterial plant pathogens. However, the mechanism(s) by which Rs counteracts host-associated environmental stress is still not clearly elucidated. To investigate possible stress management mechanisms, orthologs of stress-responsive genes in the Rs genome were searched using a reference set of known genes.
View Article and Find Full Text PDFIt is established that electron transmission through chiral molecules depends on the electron's spin. This phenomenon, termed the chiral-induced spin selectivity (CISS), effect has been observed in chiral molecules, supramolecular structures, polymers, and metal-organic films. Which spin is preferred in the transmission depends on the handedness of the system and the tunneling direction of the electrons.
View Article and Find Full Text PDFIn past studies, spin selective transport was observed in polymers and supramolecular structures that are based on homochiral building blocks possessing stereocenters. Here we address the question to what extent chiral building blocks are required for observing the chiral induced spin selectivity (CISS) effect. We demonstrate the CISS effect in supramolecular polymers exclusively containing achiral monomers, where the supramolecular chirality was induced by chiral solvents that were removed from the fibers before measuring.
View Article and Find Full Text PDFRoom-temperature, long-range (300 nm), chirality-induced spin-selective electron conduction is found in chiral metal-organic Cu(II) phenylalanine crystals, using magnetic conductive-probe atomic force microscopy. These crystals are found to be also weakly ferromagnetic and ferroelectric. Notably, the observed ferromagnetism is thermally activated, so that the crystals are antiferromagnetic at low temperatures and become ferromagnetic above ∼50 K.
View Article and Find Full Text PDFSpin-dependent conduction and polarization in chiral polymers were studied for polymers organized as self-assembled monolayers with conduction along the polymer backbone, namely, along its longer axis. Large spin polarization and magnetoresistance effects were observed, showing a clear dependence on the secondary structure of the polymer. The results indicate that the spin polarization process does not include spin flipping and hence it results from backscattering probabilities for the two spin states.
View Article and Find Full Text PDFThe brain is both central in orchestrating the response to stress, and, a very sensitive target when such response is not controlled. In fact, stress has long been associated with the onset and/or exacerbation of several neuropsychiatric disorders such as anxiety, depression, and drug addiction. The hippocampus is a key brain region involved in the response to stress, not only due to its anatomical connections with the hypothalamic-pituitary-adrenal axis but also as a major target of stress mediators.
View Article and Find Full Text PDFOrganic semiconductors and organic-inorganic hybrids are promising materials for spintronic-based memory devices. Recently, an alternative route to organic spintronic based on chiral-induced spin selectivity (CISS) is suggested. In the CISS effect, the chirality of the molecular system itself acts as a spin filter, thus avoiding the use of magnets for spin injection.
View Article and Find Full Text PDFMultiheme cytochromes, located on the bacterial cell surface, function as long-distance (>10 nm) electron conduits linking intracellular reactions to external surfaces. This extracellular electron transfer process, which allows microorganisms to gain energy by respiring solid redox-active minerals, also facilitates the wiring of cells to electrodes. While recent studies have suggested that a chiral induced spin selectivity effect is linked to efficient electron transmission through biomolecules, this phenomenon has not been investigated in extracellular electron conduits.
View Article and Find Full Text PDFThis contribution deals with the synthesis and utilization of a new pyrazole-based unsymmetrical ligand, 3-(3-carboxyphenyl)-1-pyrazole-5-carboxylic acid (HCPCA), for generating multifunctional materials. The reaction with the Co(II) salt in the presence of a co-ligand 2,9-dimethyl phenanthroline (dmphen) results in the formation of the helical compound {[Co(dmphen)(CPCA)]DMF} (). However, two isostructural monomeric complexes are formed {[M(HCPCA)(HO)], M = Co(II), () and Mn(II) ()} when reactions were carried out in the absence of dmphen.
View Article and Find Full Text PDFSpin based properties, applications, and devices are typically related to inorganic ferromagnetic materials. The development of organic materials for spintronic applications has long been encumbered by its reliance on ferromagnetic electrodes for polarized spin injection. The discovery of the chirality-induced spin selectivity (CISS) effect, in which chiral organic molecules serve as spin filters, defines a marked departure from this paradigm because it exploits soft materials, operates at ambient temperature, and eliminates the need for a magnetic electrode.
View Article and Find Full Text PDFThe first example of a pentacoordinate CoII single-ion magnet based on a P-donor ligand with vacant octahedral coordination geometry is reported here. Thorough magnetic measurements reveal the presence of field induced slow relaxation behavior with an easy-plane magnetic anisotropy. The combined theoretical and experimental studies disclose that direct and quantum tunneling processes become dominant at low temperature to relax the magnetization; however, from the thermal dependence of relaxation time it can be observed that the optical or acoustic Raman processes become important to the overall relaxation process.
View Article and Find Full Text PDFA rational approach of modulating the easy-plane magnetic anisotropy of mononuclear pentagonal bipyramidal Co single molecule magnets (SMMs) has been revealed in this paper. A class of three new pentagonal-bipyramidal complexes with formulas [Co(Hdaps)(MeOH)] (1), [Co(Hdaps)(NCS)(MeOH)]·(ClO)·(MeOH) (2), and [Co(Hdaps)(NCS)]·(MeOH) (3) (Hdaps = 2,6-bis(1-salicyloylhydrazonoethyl) pyridine) were studied. In these complexes, the axial positions are successively replaced by different O and N donar ligands in a systematic way.
View Article and Find Full Text PDFA series of tetrahedral Co complexes [CoLX] (X = NCS (1), Cl (2), Br (3) and I (4); L = 9,9-dimethyl-4,5-bis(diphenylphosphino) xanthene) based on a P-donor ligand has been prepared to investigate the influence of terminal ligand field strength on the anisotropy of Co single-ion magnets. It has been observed that heavier and softer terminal ligands are able to decrease the anisotropy of the tetrahedral Co centers. Thorough analyses of experimental and theoretical studies show that all complexes have an easy-axis type magnetic anisotropy and slow relaxation behaviors of tetrahedral Co centers.
View Article and Find Full Text PDFIn this paper, the influence of the structural and chemical effects on the Ising-type magnetic anisotropy of pentacoordinate Co complexes has been investigated by using a combined experimental and theoretical approach. For this, a deliberate design and synthesis of four pentacoordinate Co complexes [Co(tpa)Cl]⋅ClO (1), [Co(tpa)Br]⋅ClO (2), [Co(tbta)Cl]⋅(ClO )⋅(MeCN) ⋅(H O) (3) and [Co(tbta)Br]⋅ClO (4) by using the tripodal ligands tris(2-methylpyridyl)amine (tpa) and tris[(1-benzyl-1 H-1,2,3-triazole-4-yl)methyl]amine) (tbta) have been carried out. Detailed dc and ac measurements show the existence of field-induced slow magnetic relaxation behavior of Co centers with Ising-type magnetic anisotropy.
View Article and Find Full Text PDFIn this work, the effects of ligand field strength as well as the metal coordination geometry on magnetic anisotropy of pentacoordinated Co complexes have been investigated using a combined experimental and theoretical approach. For that, a strategic design and synthesis of three pentacoordinate Co complexes [Co(bbp)Cl]·(MeOH) (1), [Co(bbp)Br]·(MeOH) (2), and [Co(bbp)(NCS)] (3) has been achieved by using the tridentate coordination environment of the ligand in conjunction with the accommodating terminal ligands (i.e.
View Article and Find Full Text PDFIn this work we report two pentacoordinated Co-PX Single Ion Magnets (SIMs) based on P-donor ligands. The tetradentate ligand tris[2-(diphenylphosphino)ethyl]phosphine allows the obtention of the isostructural square pyramidal [Co(PP)Cl]·ClO (1) and [Co(PP)Br]·ClO (2) complexes. Consistent theoretical and experimental studies indicate that these complexes have a high spin (S = 3/2) ground state and suggest that the relaxation dynamics is governed by ground state quantum tunneling, whereas its temperature dependence is directed by optical or acoustic Raman processes.
View Article and Find Full Text PDFFour coordination compounds of formulae [Cu(II)2(H2L(1))(HL(1))](ClO4)3·H2O (1), [Cu(II)2(H2L(2))(CH3OH)2](ClO4)2·2CH3OH (2), [Co(II)2(H2L(1))2](ClO4)4 (3) and [Co(II)2(H2L(2))2]·2H2O (4) were synthesized via self-assembly of succinohydrazone derived ligands (H2L(1) = N',N'-4-bis(2-pyridyl)succinohydrazide, H4L(2) = N',N'-4-bis(2-hydroxybenzylidene)succinohydrazide) and Cu(2+) and Co(2+) ions, respectively. The compounds were characterized by crystal structure determination, magnetic measurements and biological activities. Compounds 1, 3 and 4 have discrete double helicate structures, whereas compound 2 is a one-dimensional chain.
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