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The Chemical Bond: When Atom Size Instead of Electronegativity Difference Determines Trend in Bond Strength.

ABSTRACT: We have quantum chemically analyzed element-element bonds of archetypal H_n X-YH_n molecules (X, Y=C, N, O, F, Si, P, S, Cl, Br, I), using density functional theory. One purpose is to obtain a set of consistent homolytic bond dissociation energies (BDE) for establishing accurate trends across the periodic table. The main objective is to elucidate the underlying physical factors behind these chemical bonding trends. On one hand, we confirm that, along a period (e. g., from C-C to C-F), bonds strengthen because the electronegativity difference across the bond increases. But, down a period, our findings constitute a paradigm shift. From C-F to C-I, for example, bonds do become weaker, however, not because of the decreasing electronegativity difference. Instead, we show that the effective atom size (via steric Pauli repulsion) is the causal factor behind bond weakening in this series, and behind the weakening in orbital interactions at the equilibrium distance. We discuss the actual bonding mechanism and the importance of analyzing this mechanism as a function of the bond distance.

SUBMITTER: Blokker E

PROVIDER: S-EPMC9298008 | biostudies-literature |

REPOSITORIES: biostudies-literature

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Angle-dependent strength of a single chemical bond by stereographic force spectroscopy.

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| S-EPMC4748171 | biostudies-literature

In-Situ Electronegativity and the Bridging of Chemical Bonding Concepts.

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Signaling strength determines proapoptotic functions of STING

Project description:T cells exhibit an intensified STING response, which leads to the expression of a distinct set of genes and results in the induction of apoptosis

2017-06-24 | GSE100411 | GEO

Mechanical and chemical surface treatment enhances bond strength between zirconia and orthodontic brackets: an in vitro study

Project description: Not available

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Strength of TRAF6 signalling determines osteoclastogenesis.

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Difference between Metal-S and Metal-O Bond Orders: A Descriptor of Oxygen Evolution Activity for Isolated Metal Atom-Doped MoS2 Nanosheets.

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Signalling strength determines proapoptotic functions of STING.

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| S-EPMC5585373 | biostudies-literature

Dimer Rhenium Tetrafluoride with a Triple Bond Re-Re: Structure, Bond Strength.

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Metal-ligand bond strength determines the fate of organic ligands on the catalyst surface during the electrochemical CO<sub>2</sub> reduction reaction.

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