scholarly journals A family of ionic supersalts with covalent-like directionality and unconventional multiferroicity

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Yaxin Gao ◽  
Menghao Wu ◽  
Puru Jena
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Building Blocks ◽  
Cluster Ions ◽  
Ionic Crystals ◽  
Functional Theory ◽  
Reversible Strain ◽  
Ionic Bonding ◽  
Cluster Ion ◽  
Ferroelectric Switching

AbstractIonic crystals composed of elemental ions such as NaCl are non-polar due to directionless ionic bonding interactions. Here, we show that these can develop polarity by changing their building blocks from elemental ions to superalkali and superhalogen cluster-ions, which mimic the chemistry of alkali and halogen atoms, respectively. Due to the non-spherical geometries of these cluster ions, corresponding supersalts form anisotropic polar structures with ionic bonding, yet covalent-like directionality, akin to sp3 hybridized systems. Using density functional theory and extensive structure searches, we predict a series of stable ferroelectric/ferroelastic supersalts, PnH4MX4 (Pn = N, P; M = B, Al, Fe; X = Cl, Br) composed of superalkali PnH4 and superhalogen MX4 ions. Unlike traditional ferroelectric/ferroelastic materials, the cluster-ion based supersalts possess ultra-low switching barrier and can endure large ion displacements and reversible strain. In particular, PH4FeBr4 exhibits triferroic coupling of ferroelectricity, ferroelasticity, and antiferromagnetism with controllable spin directions via either ferroelastic or 90-degree ferroelectric switching.

scholarly journals New Family of Ionic Supersalts with Covalent-like Directionality and Unconventional Multiferroicity

2020 ◽  
Author(s):  
Yaxin Gao ◽  
Menghao Wu ◽  
Puru Jena
Keyword(s):  
Density Functional ◽  
Building Blocks ◽  
Cluster Ions ◽  
Functional Theory ◽  
Exothermic Reactions ◽  
Ionic Bonding ◽  
New Family ◽  
Polar Materials ◽  
Switching Barriers ◽  
Covalent Nature

Abstract Ionic crystals composed of elemental ions such as NaCl are centro-symmetric and, thus, non-polar due to directionless ionic bonding interactions. To develop polar materials, the directionality feature of covalent bonding is necessary. Here, we propose a novel way where ionically bonded crystals can develop polarity by changing their building blocks from elemental ions to cluster-ions. Superalkalis and superhalogens are clusters which mimic the chemistry of alkali and halogen atoms. Equally important, unlike the elemental ions, the geometries of these superions are not spherical. Endowed with these unique features, ionic supersalts form anisotropic polar structures with ionic bonding, yet covalent-like directionality, akin to sp3 hybridized systems. Using density functional theory and extensive structure searches, we predict a series of stable supersalts, PnH4MX4 (Pn = N, P; M = B, Al, Fe; X = Cl, Br) composed of superalkali PnH4 and superhalogen MX4 ions with unprecedented properties: (1) ferroelectricity with ultra-long ion displacements (~ 3 Å); (2) ferroelasticity with ultra-large reversible strain (> 40%); and (3) both with ultra-low switching barriers (about 6 to 13 meV/atom). These values are inconceivable in traditional ferroelectric/ferroelastic materials owing to their brittle covalent nature. Coupling of ferroelectricity with ferroelasticity can further enable strain-controlled polarization as well as electrically-controlled strain. In particular, PnH4FeX4 exhibits triferroic coupling of ferroelectricity, ferroelasticity, and antiferromagnetism where the spin directions can be altered via either ferroelastic or 90-degree ferroelectric switching. These ionic supersalts can be synthesized using facile solution-processed fabrication by exothermic reactions, MPn + 4HX→PnH4MX4 or PnH4X + MX3→PnH4MX4, which may open a new chapter in multiferroics.

STRUCTURAL AND ELECTRONIC PROPERTIES OF (CnLi)+ CLUSTER IONS

2005 ◽  
Vol 16 (02) ◽  
pp. 271-280
Author(s):  
EFE YAZGAN ◽  
ŞAKIR ERKOÇ
Keyword(s):  
Density Functional Theory ◽  
Electronic Properties ◽  
Density Functional ◽  
Density Functional Theory Calculations ◽  
Vibrational Frequencies ◽  
Cluster Ions ◽  
Functional Theory ◽  
B3lyp Level ◽  
Structural And Electronic Properties

The structural and electronic properties of ( C n Li )+ cluster ions with n =1–6 and n =20 have been investigated by performing density functional theory calculations at B3LYP level. The vibrational frequencies of the clusters are also calculated.

scholarly journals Spectroscopic identification of fragment ions of DNA/RNA building blocks: the case of pyrimidine

2020 ◽  
Vol 22 (30) ◽  
pp. 17275-17290
Author(s):  
Kuntal Chatterjee ◽  
Otto Dopfer
Keyword(s):  
Density Functional Theory ◽  
Infrared Spectroscopy ◽  
Density Functional ◽  
Density Functional Theory Calculations ◽  
Building Blocks ◽  
Functional Theory ◽  
Fragment Ions ◽  
Sequential Loss ◽  
Spectroscopic Identification

The structure of the predominant fragments of the fundamental pyrimidine cation arising from sequential loss of HCN are identified by infrared spectroscopy of tagged ions and dispersion-corrected density functional theory calculations.

scholarly journals Microhydration of protonated biomolecular building blocks: protonated pyrimidine

2020 ◽  
Vol 22 (23) ◽  
pp. 13092-13107
Author(s):  
Kuntal Chatterjee ◽  
Otto Dopfer
Keyword(s):  
Density Functional Theory ◽  
Infrared Spectroscopy ◽  
Density Functional ◽  
Density Functional Theory Calculations ◽  
Building Blocks ◽  
Protonation Site ◽  
Functional Theory

The protonation site and evolution of the hydration network in microsolvated protonated pyrimidine clusters, H+Pym–(H2O)n with n = 1–4, has been explored by infrared spectroscopy and density functional theory calculations.

scholarly journals Physicochemical Insight into Coordination Systems Obtained from Copper(II) Bromoacetate and 1,10-Phenanthroline

Molecules ◽  
2020 ◽  
Vol 25 (22) ◽  
pp. 5324
Author(s):  
Ewelina Krejner ◽  
Tomasz Sierański ◽  
Marcin Świątkowski ◽  
Marta Bogdan ◽  
Rafał Kruszyński
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Density Functional Theory Calculations ◽  
Building Blocks ◽  
Radiation Absorption ◽  
Ir Absorption ◽  
Bromoacetic Acid ◽  
Functional Theory ◽  
Hirshfeld Analysis ◽  
Coordination Systems

Two different coordination compounds of copper were synthesized from the same building blocks (1,10-phenanthroline, bromoacetate anions, and copper cations). The synthesis parameters were carefully designed and evaluated to allow the change of the resulting compounds molecular structure, i.e., formation of mononuclear (bromoacetato-O,O’)(bromoacetato-O)aqua(1,10-phenanthroline-N,N’)copper(II) and dinuclear (μ-bromido-1:2κ2)bis(μ-bromoacetato-1κO,2κO’)bis(1,10-phenanthroline-N,N’)dicopper(II) bromoacetate bromoacetic acid solvate. The crystal, molecular and supramolecular structures of the studied compounds were determined and evaluated in Hirshfeld analysis. The UV-Vis-IR absorption and thermal properties were studied and discussed. For the explicit determination of the influence of compounds structure on radiation absorption in UV-Vis range, density functional theory and time-dependent density functional theory calculations were performed.

ADSORPTION REACTION OF POLAR ORGANIC MOLECULES ON ${\rm Si}^+_n$ CLUSTER IONS

2005 ◽  
Vol 19 (15n17) ◽  
pp. 2502-2507
Author(s):  
WAKANA NAKAGAWARA ◽  
HIRONORI TSUNOYAMA ◽  
ARI FURUYA ◽  
FUMINORI MISAIZU ◽  
KOICHI OHNO
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Organic Molecules ◽  
Theoretical Calculations ◽  
Cluster Ions ◽  
Silicon Cluster ◽  
Geometrical Structures ◽  
Functional Theory ◽  
Relationship Of ◽  
The Relationship

We have examined chemical reactions of small silicon cluster ions [Formula: see text] for n = 7 - 16 with polar organic molecules M ( M = CH 3 CN , CD 3 OD , C 2 H 5 CN , and C 2 H 5 OH ). The intensities of the adsorption products [Formula: see text] for m = 1 and 2 were investigated as a function of n. We found for all polar molecules that the relative intensity of Si n M + to the unreacted [Formula: see text] is smaller for n = 11, 13, and 14, that is, the adsorption reactivity is smaller for these n than others. It was also commonly observed that the [Formula: see text] ion are more intense than neighboring n. We discussed the relationship of the reactivity with the geometrical structures and the stabilities of the bare [Formula: see text] ions and adsorbed [Formula: see text] ions, from theoretical calculations based on density functional theory.

scholarly journals Neutral Rhenadicarbaboranes with Re(CO)2(NO) Vertices: A Theoretical Study of Building Blocks for Rhenacarborane-Based Drug Delivery Agents

Molecules ◽  
2019 ◽  
Vol 25 (1) ◽  
pp. 110 ◽  
Author(s):  
Amr A. A. Attia ◽  
Alexandru Lupan ◽  
Radu Silaghi-Dumitrescu ◽  
R. Bruce King
Keyword(s):  
Drug Delivery ◽  
Density Functional Theory ◽  
Carbon Atom ◽  
Related Species ◽  
Density Functional ◽  
Theoretical Study ◽  
Building Blocks ◽  
Rhenium Atom ◽  
Functional Theory

The rhenadicarbaborane carbonyl nitrosyls (C2Bn−3Hn−1)Re(CO)2(NO), (n = 8 to 12), of interest in drug delivery agents based on the experimentally known C2B9H11Re(CO)2(NO) and related species, have been investigated by density functional theory. The lowest energy structures of these rhenadicarbaboranes are all found to have central ReC2Bn−3 most spherical closo deltahedra in accord with their 2n + 2 Wadean skeletal electrons. Carbon atoms are found to be located preferentially at degree 4 vertices in such structures. Furthermore, rhenium atoms are preferentially located at a highest degree vertex, typically a vertex of degree 5. Only for the 9-vertex C2B6H8Re(CO)2(NO) system are alternative isocloso deltahedral isomers found within ~8 kcal/mol of the lowest energy closo isomer. Such 9-vertex isocloso structures provide a degree 6 vertex for the rhenium atom flanked by degree 4 vertices for each carbon atom.

scholarly journals Phosphorus(III)-assisted regioselective C–H silylation of heteroarenes

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Dingyi Wang ◽  
Xiangyang Chen ◽  
Jonathan J. Wong ◽  
Liqun Jin ◽  
Mingjie Li ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Palladium Catalyst ◽  
Density Functional ◽  
Functional Group ◽  
Building Blocks ◽  
General Strategy ◽  
Indole Derivatives ◽  
Functional Theory ◽  
Synthetic Strategy ◽  
Directing Group

AbstractHeteroarenes containing carbon–silicon (C–Si) bonds are important building blocks that play an important role in the construction of natural products, pharmaceuticals, and organic materials. In this context, the C–H silylation of heteroarenes is a topic of intense interest. Indole C–H silylation can preferentially occur at the nucleophilic C3 and C2 position (pyrrole core), while accessing the C4-C7 positions (benzene core) of the indole remains highly challenging. Here, we show a general strategy for the regioselective C7-H silylation of indole derivatives. Mainly, the regioselectivity is determined by strong coordination of the palladium catalyst with phosphorus (III) directing group. Using this expedient synthetic strategy, the diverse C7-silylated indoles are synthesized effectively which exhibits the broad functional group compatibility. Moreover, this protocol also been extended to other heteroarenes such as carbazoles. The obtained silylated indoles have been employed in various transformations to enable the corresponding differently functionalized indole derivatives. Significantly, a cyclopalladated intermediate is successfully synthesized to test the hypothesis about the P(III)-directed C–H metalation event. A series of mechanistic experiments and density functional theory (M06-2X) calculations has shown the preferred pathway of this directed C–H silylation process.

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