Electronegativities of nitrogen, phosphorus, arsenic, antimony and bismuth

Allred, A. L.; Hensley, Alexander

doi:10.1016/0022-1902(61)80184-x

Cited by 44 publications

(20 citation statements)

References 23 publications

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“…As we can see, moving down the 15 group (N → P) and increasing the atomic radii of apical substituents essentially narrow the bandgap by about 0.6 eV. Narrowing should also be related to the much smaller electronegativity of P (2.19) compared to N …”

Section: Resultsmentioning

confidence: 77%

“…Narrowing is especially remarkable since P (2.19) and As (2.18) have almost the same electronegativities in the Pauling scale. 78 Thus, band gap changes here are dictated by the size of quasi-octahedral units in the first place. Intuitively, band gap engineering through isoelectronic substitution could be explained as follows: when we increase the lattice size by apical substitution, electrons confined within a cell become "less bound" and are more easily promoted to the conduction zone.…”

Section: Resultsmentioning

confidence: 97%

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Band Gap Engineering and 14 Electron Superatoms in 2D Superoctahedral Boranes B₄X₂ (B, N, P, As, Sb)

et al. 2021

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Band gap tuning in 2D monolayers is one of the most attractive approaches in design and production of new atomically thin semiconductors. Following our recent computational design of stable two-dimensional octahedral boranes, we present comprehensive computational study of electronic structure, stability and properties of members belonging to family B4X2 (X = B, N, P, As, Sb). We select 15 group atoms (pnictogens) as apical substituents to stabilize quasi-octahedral units by delocalized bonding and create interlayer “pressure” caused by vertically aligned lone pairs. We first substitute apical B atoms by N and then go down the 15 group to capture electronic structure trends. B→N substitution opens band gap, while further substitution consistently narrows band gap. We revealed elegant band gap trend which is inversely proportional to the size of octahedral units. Thus, old as world isoelectronic substitution could be used for band gap engineering in superoctahedral 2D boranes and other monolayers. We also discovered superatomic bonding in B4As2 and B4P2 octahedra which agrees with their exceptional stability (up to 800 K) and magnetic response properties. Remarkably, both B4As2 and B4P2 units have 14 valence electrons, making them exceptional examples of stable nonconventional electron count of spherical aromaticity. Alongside with a considerable negative formation energy and phonon stability, B4As2 has extremely low exfoliation energy of 0.02 eV/atom implying probability of synthetic route from a putative bulk material. It gives a strong basis to believe in possibility of experimental fabrication of B4As2 monolayer which can serve as alternative to MoS2 and silicon.

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Section: Resultsmentioning

confidence: 77%

Section: Resultsmentioning

confidence: 97%

Band Gap Engineering and 14 Electron Superatoms in 2D Superoctahedral Boranes B₄X₂ (B, N, P, As, Sb)

et al. 2021

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“…For example, lowfield shifts amounting to 1.4 p.p.m. per unit increase in electronegativity are noted (25) for the methyl protons in a series of methyl halides. However, inductive effects drop off very rapidly with the number of intervening bonds and shift changes for P protons are approximately 1/10 those of cl protons in saturated compounds (1)(2)(3).…”

Section: Comparison With Earlier Parametersmentioning

confidence: 90%

“…Inductive effects, arising primarily from electronegativity differences of substituent groups and operating via the o electron system, are known to exert an appreciable influence upon proton shifts (2,3,24,25). For example, lowfield shifts amounting to 1.4 p.p.m.…”

Section: Comparison With Earlier Parametersmentioning

confidence: 99%

Proton magnetic resonance spectra of vinylmetallic compounds. Part I. Tetravinyl and triphenylvinyl derivatives of Group IVB elements

Cawley¹,

Danyluk²

1968

Can. J. Chem.

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A study has been made of the proton magnetic resonance spectra for all of the Group IVB derivatives of the series MVi, and 43MVi (4 = phenyl group and Vi = vinyl group). The spectra were measured at 60 MHz as accurately as possible and the assignment of transitions was checked with a variety of supplemental aids including double irradiation, nlultiple quantum transitions, and medium effects. Final, accurate spectral parameters were derived using both iterative and exact comp~~tational methods for solution of the three-spin problem. Excellent agreement was obtained between the sets of parameters determined by the two methods.The clien~ical shifts for both series of compounds display a nunlber of characteristic trends of which the most notable is a displacenlent of the vinyl proton signals to low field with increasing atomic number of the M atom. In each series the largest shift change is noted in going from the carbon to the silicon dcrivative. These deshicldings have been attributed to the enhanced possibility of d,-p, interaction between the central M atoll1 and the vinyl group in higher nlenlbers of the series. Marked changes are also noted for the internal shifts of the vinyl protons down both series of compounds. It is concluded that these changes are principally due to the effects of the M-C bond diamagnetic anisotropy. The trends in internal shifts can be satisfactorily reproduced by the dipole approxin~ation using AX values of 4, 6, 8, 12, and 18 x cnl3 mole-' for the C, Si, Ge, Sn, and Pb-carbon bonds respectively. The signals for the vinyl protons of the &MVi series are all located to low field relative to the MVi, series. This deshielding is satisfactorily accounted for by the effects of the phenyl ring diamagnetic anisotropy in the former series.A linear correlation is observed between the sums of the coupling constants and the electronegativities, Em, of the central M atom for both series of compounds. However, the XJvalues for the &MVi series are all slightly lower than the corresponding s u n~s for the MVi4 series, indicating that the electronegativity of the phenyl group is somewhat larger than for the vinyl group.A significant solvent and concentration dependence is only noted for compounds belonging to the &MVi series. For examplc, the tratis proton of +3GeVi shifts up-field by 4 Hz while the cis proton is displaced down-field by 4 Hz as the concentration of 4,GeVi is increased to 50 mole % in carbon tetrachloride. These changes have been interpreted on the basis of a solute-solute interaction scheme of the type proposed previously for phenyl proton shifts.

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“…In the second, introducing heteroatoms such as nitrogen into the porous structure increases the adsorption selectivity. The nitrogen atom has a partial negative charge due to its lone pair electrons and its high electronegativity [19,20]. Such a Lewis base character provides a chemical affinity toward CO 2 .…”

Section: Introductionmentioning

confidence: 99%

Rearranged Copolyurea Networks for Selective Carbon Dioxide Adsorption at Room Temperature

et al. 2021

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Copolyurea networks (co-UNs) were synthesized via crosslinking polymerization of a mixture of tetrakis(4-aminophenyl)methane (TAPM) and melamine with hexamethylene diisocyanate (HDI) using the organic sol-gel polymerization method. The subsequent thermal treatment of between 200 and 400 °C induced the sintering of the powdery polyurea networks to form porous frameworks via urea bond rearrangement and the removal of volatile hexamethylene moieties. Incorporating melamine into the networks resulted in a higher nitrogen content and micropore ratio, whereas the overall porosity decreased with the melamine composition. The rearranged network composed of the tetraamine/melamine units in an 80:20 ratio showed the highest carbon dioxide adsorption quantity at room temperature. The results show that optimizing the chemical structure and porosity of polyurea-based networks can lead to carbon dioxide adsorbents working at elevated temperatures.

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Electronegativities of nitrogen, phosphorus, arsenic, antimony and bismuth

Cited by 44 publications

References 23 publications

Band Gap Engineering and 14 Electron Superatoms in 2D Superoctahedral Boranes B₄X₂ (B, N, P, As, Sb)

Band Gap Engineering and 14 Electron Superatoms in 2D Superoctahedral Boranes B₄X₂ (B, N, P, As, Sb)

Proton magnetic resonance spectra of vinylmetallic compounds. Part I. Tetravinyl and triphenylvinyl derivatives of Group IVB elements

Rearranged Copolyurea Networks for Selective Carbon Dioxide Adsorption at Room Temperature

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Electronegativities of nitrogen, phosphorus, arsenic, antimony and bismuth

Cited by 44 publications

References 23 publications

Band Gap Engineering and 14 Electron Superatoms in 2D Superoctahedral Boranes B4X2 (B, N, P, As, Sb)

Band Gap Engineering and 14 Electron Superatoms in 2D Superoctahedral Boranes B4X2 (B, N, P, As, Sb)

Proton magnetic resonance spectra of vinylmetallic compounds. Part I. Tetravinyl and triphenylvinyl derivatives of Group IVB elements

Rearranged Copolyurea Networks for Selective Carbon Dioxide Adsorption at Room Temperature

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Product

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Band Gap Engineering and 14 Electron Superatoms in 2D Superoctahedral Boranes B₄X₂ (B, N, P, As, Sb)

Band Gap Engineering and 14 Electron Superatoms in 2D Superoctahedral Boranes B₄X₂ (B, N, P, As, Sb)