Analysis of Electronic Structures and Chemical Bonding of Metal‐rich Compounds. 2. Presence of Dimer (T–T)4– and Isolated T2– Anions in the Polar Intermetallic Cr5B3‐Type Compounds AE5T3 (AE = Ca, Sr; T = Au, Ag, Hg, Cd, Zn)

Lee, Chang‐Hoon; Whangbo, Myung‐Hwan; Köhler, Jürgen

doi:10.1002/zaac.200900421

Cited by 18 publications

(9 citation statements)

References 28 publications

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“…The existence of reduced group 12 elements, where these transition metal atoms occupy their p-levels, is also in agreement with their high electronegativities. Some examples here are dimeric Zintl anions in compounds of the type Ca 3 Hg 2 and Ca 5 M 3 (M = Zn, Cd, and Hg). , …”

Section: Zinc Cadmium and Mercurymentioning

confidence: 99%

Electronegativity Seen as the Ground-State Average Valence Electron Binding Energy

2018

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We introduce a new electronegativity scale for atoms, based consistently on ground-state energies of valence electrons. The scale is closely related to (yet different from) L. C. Allen's, which is based on configuration energies. Using a combination of literature experimental values for ground-state energies and ab initiocalculated energies where experimental data are missing, we are able to provide electronegativities for elements 1−96. The values are slightly smaller than Allen's original scale, but correlate well with Allen's and others. Outliers in agreement with other scales are oxygen and fluorine, now somewhat less electronegative, but in better agreement with their chemistry with the noble gas elements. Group 11 and 12 electronegativities emerge as high, although Au less so than in other scales. Our scale also gives relatively high electronegativities for Mn, Co, Ni, Zn, Tc, Cd, Hg (affected by choice of valence state), and Gd. The new electronegativities provide hints for new alloy/compound design, and a framework is in place to analyze those energy changes in reactions in which electronegativity changes may not be controlling.

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Section: Zinc Cadmium and Mercurymentioning

confidence: 99%

Electronegativity Seen as the Ground-State Average Valence Electron Binding Energy

2018

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“…Recently, all-metal extended Zintl polyanions − have been found capable of pushing the valence electrons provided to form excess electrons, which result in the generation of a novel kind of compounds. Interesting examples include [(Ca 2+ ) 5 (Ag–Ag) 4– (Ag 2– )]+4e – and [(Ca 2+ ) 5 (Au–Au) 4– (Au 2– )]+4e – with dimer polyanion and magnetic superatoms A n V (A = Na and Cs; n = 6–12) with monomer polyanion . This novel kind of species not only has an all-metal composition features but also has electride characteristic with excess electron anions.…”

Section: Introductionmentioning

confidence: 99%

Efficient External Electric Field Manipulated Nonlinear Optical Switches of All-Metal Electride Molecules with Infrared Transparency: Nonbonding Electron Transfer Forms an Excess Electron Lone Pair

Lü

Yang

et al. 2016

J. Phys. Chem. C

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Focusing on the interesting new concept of all-metal electride, centrosymmetric molecules e–+M2+(Ni@Pb12)2–M2++e– (M = Be, Mg, and Ca) with two anionic excess electrons located at the opposite ends of the molecule are obtained theoretically. These novel molecular all-metal electrides can act as infrared (IR) nonlinear optical (NLO) switches. Whereas the external electric field (F) hardly changes the molecular structure of the all-metal electrides, it seriously deforms their excess electron orbitals and average static first hyperpolarizabilities (β0 e(F)). For e–+Ca2+(Ni@Pb12)2–Ca2++e–, a small external electric field F = 8 × 10–4 au (0.04 V/Å) drives a long-range excess electron transfer from one end of the molecule through the middle all-metal anion cage (Ni@Pb12)2– to the other end. This long-range electron transfer is shown by a prominent change of excess electron orbital from double lobes to single lobe, which forms an excess electron lone pair and electronic structure Ca2+(Ni@Pb12)2–Ca2++2e–. Therefore, the small external electric field induces a dramatic β0 e(F) contrast from 0 (off form) to 2.2 × 106 au (on form) in all-metal electride molecule Ca(Ni@Pb12)Ca. Obviously, such switching is high sensitive. Interestingly, in the switching process, such long-range excess electron transfer does not alter the valence and chemical bond nature. Then, this switching mechanism is a distinct nonbonding evolution named electronic structure isomerization, which means that such switching has the advantages of being fast and reversible. Besides, these all-metal electride molecules also have a rare IR transparent characteristic (1.5–10 μm) in NLO electride molecules, and hence are commendable molecular IR NLO switches. Therefore, this work opens a new research field of electric field manipulated IR NLO switches of molecular all-metal electrides.

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“…Experimental and theoretical studies have shown that all-metal extended Zintl polyanions − are more capable of pushing the valence electrons of an electron donor to form excess electrons. Having an insight into polar intermetallic compounds with Zintl polyanions, we have proposed a new concept “all-metal electride” and designed and researched all-metal electride NLO molecules CuAg@Ca 7 M (M = Be, Mg and Ca) .…”

Section: Introductionmentioning

confidence: 99%

Effects of the Cage Number and Excess Electron Number on the Second Order Nonlinear Optical Response in Molecular All-Metal Electride Multicage Chains

Yang

et al. 2017

J. Phys. Chem. C

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For novel all-metal electride, multicage chain structures [(Ni@ Ge 9 ) Ca 3 ] n (n = 1−4) with all real frequencies are obtained theoretically for the first time. In the structure of n = 1, the Ni@Ge 9 metal cage as the shortest chain skeleton is surrounded by nonbridge Ca atoms. In the structures of n = 2−4, Ni@Ge 9 metal cages are connected by bridge Ca atom pair(s) forming new hybrid multicage chain skeletons surrounded by nonbridge Ca atoms. And interesting pull−push electron relay occurs. The chain skeleton pulls valence electrons from nonbridge Ca atoms forming skeleton polyanion, and then formed polyanion pushes remaining valence electrons of the Ca atoms forming excess electrons. The excess electron numbers are Ne = 2, 0, 4, 4 for n = 1, 2, 3, 4, respectively. It is shown that these structures with excess electrons are molecular all-metal electride multicage chains, unexpectedly, and the structure (n = 2) without excess electron is a Ca salt. For nonlinear optical (NLO) response, the electride chains have large static first hyperpolarizabilities (β 0 e ). And β 0 e increases strongly from 9321 (n = 1, N e = 2) to 54232 au (n = N e = 4), which exhibits that significant cage number and excess electron number effects on NLO response. Besides electronic contribution (β 0 e ) to static first hyperpolarizability, the large vibrational contribution (β 0 nr ) are also revealed, and the ratios of β 0 nr /β 0 e are 0.18−1.17. Moreover, the frequency-dependent values β e (−2ω; ω, ω) and β e (−ω; ω, 0) have also been estimated. Especially, the evolutions of prominent cage number effects on β 0 e , β 0 nr , β e (−2ω; ω, ω) and β e (−ω; ω, 0) are similar. Then a new design strategy of enhancing NLO response by increasing metalcage number is obtained. Hence, these molecular all-metal electride multicage chains as novel nanorods are promising new NLO nanomaterials.

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Analysis of Electronic Structures and Chemical Bonding of Metal‐rich Compounds. 2. Presence of Dimer (T–T)^4– and Isolated T^2– Anions in the Polar Intermetallic Cr₅B₃‐Type Compounds AE₅T₃ (AE = Ca, Sr; T = Au, Ag, Hg, Cd, Zn)

Abstract: First principles density functional calculations were carried out to probe the oxidation states of the transition-metal and alkalineearth elements in the Cr 5 B 3 -type compounds AE 5 T 3 consisting of T 2 dimers and isolated T atoms (i.e., Ca

Cited by 18 publications

References 28 publications

Electronegativity Seen as the Ground-State Average Valence Electron Binding Energy

Electronegativity Seen as the Ground-State Average Valence Electron Binding Energy

Efficient External Electric Field Manipulated Nonlinear Optical Switches of All-Metal Electride Molecules with Infrared Transparency: Nonbonding Electron Transfer Forms an Excess Electron Lone Pair

Effects of the Cage Number and Excess Electron Number on the Second Order Nonlinear Optical Response in Molecular All-Metal Electride Multicage Chains

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