Solid-state electronegativity of atoms: new approaches

Electronegativities (EN) of 65 elements (H to Bi, except lanthanides and noble gases, plus U and Th) in solids were derived from various observed parameters, namely, bond energies in solids, structural geometry, work functions and force constants, yielding a set of internally consistent values. The solid-state electronegativities are generally lower than the conventional (`molecular') values, due to different coordination numbers and electronic structure in a solid versus a molecule; the decrease is stronger for metals than for non-metals, hence binary compounds have a wider EN difference and higher bond polarity (ionicity) in the solid than in the molecular (gaseous) state. Under high pressure, the ENs of metals increase and those of non-metals decrease, the binary solid becomes less polar and can ultimately dissociate into elements.

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Thermochemical electronegativities of the elements

Nature Communications ◽

10.1038/s41467-021-22429-0 ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

Christian Tantardini ◽

Artem R. Oganov

Keyword(s):

Solid State ◽

Chemical Bonding ◽

Structural Chemistry ◽

Solid State Chemistry ◽

Structure And Properties ◽

Bond Energies ◽

Dimensionless Numbers ◽

Bond Polarity ◽

Stability Structure ◽

Definition Of

AbstractElectronegativity is a key property of the elements. Being useful in rationalizing stability, structure and properties of molecules and solids, it has shaped much of the thinking in the fields of structural chemistry and solid state chemistry and physics. There are many definitions of electronegativity, which can be roughly classified as either spectroscopic (these are defined for isolated atoms) or thermochemical (characterizing bond energies and heats of formation of compounds). The most widely used is the thermochemical Pauling’s scale, where electronegativities have units of eV−1/2. Here we identify drawbacks in the definition of Pauling’s electronegativity scale—and, correcting them, arrive at our thermochemical scale, where electronegativities are dimensionless numbers. Our scale displays intuitively correct trends for the 118 elements and leads to an improved description of chemical bonding (e.g., bond polarity) and thermochemistry.

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Synthesis and Characterization of Ethylenedithio-MPTTF-PTM Radical Dyad as a Potential Neutral Radical Conductor

10.20944/preprints201611.0030.v1 ◽

2016 ◽

Author(s):

Manuel Souto ◽

Dan Bendixen ◽

Morten Jensen ◽

Jan O. Jeppesen ◽

Imma Ratera ◽

...

Keyword(s):

High Pressure ◽

Electronic Structure ◽

Solid State ◽

Energy Gap ◽

Synthesis And Characterization ◽

Small Energy ◽

Neutral Radical ◽

New Material ◽

Potential Use

During the last years there has been a high interest in the development of new purely-organic single-component conductors. Very recently, we have reported a new neutral radical conductor based on the perchlorotriphenylmethyl (PTM) radical moiety linked to a monopyrrolo-tetrathiafulvalene (MPTTF) unit by a -conjugated bridge (1). Interestingly, this system behaves as a semiconductor with high conductivity and small energy gap under high pressure. With the aim of developing a new material with improved conducting properties, we have designed and synthesized the radical dyad 2 which was functionalized with an ethylenedithio (EDT) group in order to improve the intermolecular interactions of the TTF subunits. The physical properties of the new radical dyad 2 were studied in detail in solution to further analyze its electronic structure as well as its potential use as radical conductor in the solid state.

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