Theory of zwitterionic molecular-based organic magnets

Shelton, W. A.; Aprà, Edoardo; Sumpter, Bobby G.; Saraiva-Souza, Aldilene; Filho, A. G. Souza; Nero, Jordan Del; Meunier, Vincent

doi:10.1016/j.cplett.2011.06.028

Cited by 7 publications

(5 citation statements)

References 37 publications

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“…Protonation of the as-crystallized peptide backbones is accompanied by the possibility of spin polarization, the latter being naturally introduced as a fundamental parameter of the peptide ground state under a particular formal charge (see Table 1 ). The facility for spin polarization is also on a par with mounting evidence that biological complexes, such as π-conjugated zwitterionic molecules, may exhibit a ferromagnetic ground state (Shelton et al, 2011 ). In this study, polarization is regarded to be owing to a stimulus external to the peptide.…”

Section: Resultsmentioning

confidence: 99%

“…Although the ability of the pMHC complex to activate T cells is customarily addressed via the affinity (or t 1/2 ) of peptide binding to the TCR, t 1/2 operates on the molecular (phenotypic) level and is not physically relevant to the quantum state of the peptide. On the contrary, charge and spin polarization are both central to the peptide quantum state and, as previously mentioned, there is firm experimental evidence of the existence of both in various biomolecular polymers (Shelton et al, 2011 ); if, however, charge and spin are indeed allowed to act on the peptide, the fundamental question of which charge/spin combination might be probable under “normal” conditions is inherently raised. Fortunately, all peptide structures yield a very consistent cumulative coordination profile, which explicitly differentiates the agonist from the antagonist peptides, as shown in Figure 2A .…”

Section: Discussionmentioning

confidence: 99%

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Quantum chemical calculations predict biological function: the case of T cell receptor interaction with a peptide/MHC class I

Antipas

Germenis

2015

Front. Chem.

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A combination of atomic correlation statistics and quantum chemical calculations are shown to predict biological function. In the present study, various antigenic peptide-Major Histocompatibility Complex (pMHC) ligands with near-identical stereochemistries, in complexation with the same T cell receptor (TCR), were found to consistently induce distinctly different quantum chemical behavior, directly dependent on the peptide's electron spin density and intrinsically expressed by the protonation state of the peptide's N-terminus. Furthermore, the cumulative coordination difference of any variant in respect to the native peptide was found to accurately reflect peptide biological function and immerges as the physical observable which is directly related to the immunological end-effect of pMHC-TCR interaction.

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Section: Resultsmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Quantum chemical calculations predict biological function: the case of T cell receptor interaction with a peptide/MHC class I

Antipas

Germenis

2015

Front. Chem.

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“…Organic magnetic materials are of general interest because special effects can be expected such as the ferromagnetism, giant magnetoresistance, magnetic Seebeck effect, etc. ; the low heat conductivity of organic materials is important for the latter [ 51 – 54 ]. The unpaired spin of 5a and 8a , respectively, persists in the solid state and allows the study of magnetic ordering.…”

Section: Magnetic Properties Of the Radical Anionsmentioning

confidence: 99%

Persistent radical anions in the series of peri-arylenes: broadband light absorption until far in the NIR and purely organic magnetism

Langhals¹,

Ritter-Faizade

Stadler

et al. 2019

Monatsh Chem

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Stable radicals in organic conjugated molecules are of great interest due to their magnetic signals and broad optical absorptions. In this paper, we report on naphthalene, benzoperylene, perylene, terrylene, and quaterrylene carboximides, reduced under controlled conditions, where stable metal-free solid salts of radical anions could be obtained forming darkly colored solutions with line-rich UV/Vis/NIR spectra and exhibiting special magnetic properties. The most bathochromic shift of the absorption maxima extend from 760 until 1700 nm. Persistent paramagnetic properties of the solids were observed and temperature-dependent susceptibilities are measured. Graphical abstract

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“…Organic crystals can exhibit many interesting properties including luminescence [1,2], nonlinear optical [3,4], or magnetic [5,6] properties, etc. Therefore, developing organic crystal materials with advantages of light-weight, flexible, low-cost, and environmentally benign characteristics is in increasing demand, yet needs elaborate chemical designs and/or supramolecular interactions for objective functions.…”

Section: Introductionmentioning

confidence: 99%

Crystal Structure and Magnetic Property of 2-(Imidazo[1,2-a]pyri-din-2-yl)-2-oxoacetic Acid and Its Perchlorate

Shen

Zhang

Yong

2015

Chinese Journal of Chemical Physics

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We herein report two crystals based on 2-(imidazo[1,2-a]pyridin-2-yl)-2-oxoacetic acid radical and its perchlorate, and investigate the relationship between magnetic properties and crystal stacking structures or supramolecular interactions. 2-(imidazo[1,2-a]pyridin-2-yl)-2-oxoacetic acid radical in two crystals mainly exist as diamagnetic dimer formed via short atomic contacts or supramolecular interactions (hydrogen bonds, anion-π or lonepair-π interactions), leading to low magnetic susceptibilities. 2-(imidazo[1,2-a]pyridin-2-yl)-2-oxoacetic acid radical crystal exhibits quasi-one-dimensional columnar stacking chain and weak antiferromagnetism. However, its perchlorate crystal possesses one-dimensional doublestranded chain structure assembled through double hydrogen bonds and anion-π interactions, and reveals weak ferromagnetism.

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Theory of zwitterionic molecular-based organic magnets

Cited by 7 publications

References 37 publications

Quantum chemical calculations predict biological function: the case of T cell receptor interaction with a peptide/MHC class I

Quantum chemical calculations predict biological function: the case of T cell receptor interaction with a peptide/MHC class I

Persistent radical anions in the series of peri-arylenes: broadband light absorption until far in the NIR and purely organic magnetism

Crystal Structure and Magnetic Property of 2-(Imidazo[1,2-a]pyri-din-2-yl)-2-oxoacetic Acid and Its Perchlorate

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