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Rohmer, Marie‐Madeleine; Bénard, Marc

doi:10.1039/b101270n

Cited by 131 publications

(104 citation statements)

References 43 publications

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“…Diamond-shaped peroxides with electropositive substituents (Li or BeH) [14] or transition metal atoms [15,16] have been discussed in the literature. Therefore, we will also consider both isomeric forms of the mercury oxide dimer, which can be related by bond stretch isomerism.…”

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confidence: 99%

Revision of the Dissociation Energies of Mercury Chalcogenides—Unusual Types of Mercury Bonding

Filatov

Cremer

2004

ChemPhysChem

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Mercury chalcogenides HgE (E=O, S, Se, etc.) are described in the literature to possess rather stable bonds with bond dissociation energies between 53 and 30 kcal mol(-1), which is actually difficult to understand in view of the closed-shell electron configuration of the Hg atom in its ground state (...4f(14)5d(10)6s(2)). Based on relativistically corrected many body perturbation theory and coupled-cluster theory [IORAmm/MP4, Feenberg-scaled IORAmm/MP4, IORAmm/CCSD(T)] in connection with IORAmm/B3LYP theory and a [17s14p9d5f]/aug-cc-pVTZ basis set, it is shown that the covalent HgE bond is rather weak (2-7 kcal mol(-1)), the ground state of HgE is a triplet rather than a singlet state, and that the experimental bond dissociation energies have been obtained for dimers (or mixtures of monomers, dimers, and even trimers) Hg2E2 rather than true monomers. The dimers possess association energies of more than 100 kcal mol(-1) due to electrostatic forces between the monomer units. The covalent bond between Hg and E is in so far peculiar as it requires a charge transfer from Hg to E (depending on the electronegativity of E) for the creation of a single bond, which is supported by electrostatic forces. However, a bonding between Hg and E is reduced by strong lone pair-lone pair repulsion to a couple of kcal mol(-1). Since a triplet configuration possesses somewhat lower destabilizing lone pair energies, the triplet state is more stable. In the dimer, there is a Hg-Hg pi bond of bond order 0.66 without any a support. Weak covalent Hg-O interactions are supported by electrostatic bonding. The results for the mercury chalcogenides suggests that all experimental dissociation energies for group-12 chalcogenides have to be revised because of erroneous measurements.

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confidence: 99%

Revision of the Dissociation Energies of Mercury Chalcogenides—Unusual Types of Mercury Bonding

Filatov

Cremer

2004

ChemPhysChem

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“…Nach einer ersten theoretischen Diskussion dieses Effekts [6] und seiner scheinbaren experimentellen Bestätigung wurde die Bindungsdehnungsisomerie kontrovers diskutiert. [7][8][9] Interessant ist, dass "Jahn-Teller-Isomere" (Abbildung 1 c) bisher nicht in diesem Zusammenhang erwähnt wurden, obwohl sie die Bedingungen für Bindungsdehnungsisomerie erfüllen. Vielleicht ist dies darauf zurückzuführen, dass keine Cu II -Komplexe mit asymmetrischen Liganden bekannt waren, von denen Konformere isoliert und strukturell analysiert werden konnten, die Minima der Potentialfläche entsprechen (Abbildung 1 c).…”

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Bindungsdehnungsisomerie: lokalisierte Strukturen von sechsfach koordinierten Kupfer(II)‐Bispidinkomplexen entlang einer Jahn‐Teller‐aktiven Vibrationsmode

et al. 2003

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“…This is an issue of potentially wide-ranging scope, [32,33] but we focus here only on its application to a particular class of species, metal-oxo (or metal-sulfur, in a couple of examples) coordination complexes. A detailed history was published a few years ago by Parkin; [34] a much briefer summary follows.…”

Section: Case 2: Bond-stretch Isomerism-some Evidence Is More Equal Tmentioning

confidence: 99%

Controversy in Chemistry: What Counts as Evidence?—Two Studies in Molecular Structure

Labinger

Weininger

2004

Angew Chem Int Ed

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Hindsight is a wonderful thing: Controversies are always difficult to characterize while they are in progress; however, as shown for the cases of stereochemistry and bond‐stretch isomerization, it is much easier once all the evidence has been amassed. These two examples have demonstrated how important it is to consider all the experimental results before coming to a conclusion. The second example shows above all that some evidence is more equal than others—crystal‐structure analysis was considered at all stages to be the most reliable.

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Cited by 131 publications

References 43 publications

Revision of the Dissociation Energies of Mercury Chalcogenides—Unusual Types of Mercury Bonding

Revision of the Dissociation Energies of Mercury Chalcogenides—Unusual Types of Mercury Bonding

Bindungsdehnungsisomerie: lokalisierte Strukturen von sechsfach koordinierten Kupfer(II)‐Bispidinkomplexen entlang einer Jahn‐Teller‐aktiven Vibrationsmode

Controversy in Chemistry: What Counts as Evidence?—Two Studies in Molecular Structure

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