Increased-Valence Structures for Qualitative Valence-Bond Representations of Electronic Structure for Electron-Rich Molecules

Harcourt, Richard D.

doi:10.1002/1099-0682(200009)2000:9<1901::aid-ejic1901>3.0.co;2-n

Cited by 43 publications

(14 citation statements)

References 89 publications

(57 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Qualitative MO and VB approaches are known to be equivalent in this case [25,26]. These resonance structures look similar to three electron bond Valence Bond configurations of Green and Linnet [8], and Harcourt [10][11][12][13] that result from delocalizing an A or B atom lone pair electron into the Ψ AB bonding molecular orbital. ( · .…”

Section: Vif Resonance Structures For Dative 3e/2c and 3-centered Bmentioning

confidence: 88%

“…Various VB bonding models have been inspired by the Linnet approach [10][11][12][13]. The Bohr orbit model with a maximum of 2n electrons in planar circular orbits is restricted from matching molecular symmetry properties and hence chemical and physical properties in some cases, O 2 triplet for example.…”

Section: Three Dimensional Molecular Structural Formulasmentioning

confidence: 99%

“…Donor-acceptor bonding, three-electron bonding, and three-center boding have been significant in the development of bonding concepts [12,14]. Figure 7 shows sets of VIF resonance structures related by the pictorial rules (left) and their corresponding matrix transformations (right) for a donor-acceptor dative bond (top) and for a three electron -two center bond (bottom).…”

Section: Vif Resonance Structures For Dative 3e/2c and 3-centered Bmentioning

confidence: 99%

“…The treatment here is inspired by Harcourt's approach utilizing Increased Valence structures [12]. See structures 24-29 in [12].…”

Section: Vif Description Of the Binding Of O 2 To Fe(ii)mentioning

confidence: 99%

“…These modified Lewis structures, considered along with notions of electron repulsion and electron spin correlation allow the properties of molecules with odd numbers of electrons to be rationalized more clearly. Harcourt, inspired by Linnett's approach, has shown further equivalence between VB and MO treatments of the three electron bond and using a VB approach has shown how fractional electron pair bonds in "increased valence structures" are applied to give insight into a number of important examples [10][11][12][13]. VB and MO theories are not equivalent in all cases.…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Chemical Reasoning Based on an Invariance Property: Bond and Lone Pair Pictures in Quantum Structural Formulas

Alia

2010

Symmetry

View full text Add to dashboard Cite

Abstract:Chemists use one set of orbitals when comparing to a structural formula, hybridized AOs or NBOs for example, and another for reasoning in terms of frontier orbitals, MOs usually. Chemical arguments can frequently be made in terms of energy and/or electron density without the consideration of orbitals at all. All orbital representations, orthogonal or not, within a given function space are related by linear transformation. Chemical arguments based on orbitals are really energy or electron density arguments; orbitals are linked to these observables through the use of operators. The Valency Interaction Formula, VIF, offers a system of chemical reasoning based on the invariance of observables from one orbital representation to another. VIF pictures have been defined as one-electron density and Hamiltonian operators. These pictures are classified in a chemically meaningful way by use of linear transformations applied to them in the form of two pictorial rules and the invariance of the number of doubly, singly, and unoccupied orbitals or bonding, nonbonding, and antibonding orbitals under these transformations. The compatibility of the VIF method with the bond pair -lone pair language of Lewis is demonstrated. Different electron lone pair representations are related by the pictorial rules and have stability understood in terms of Walsh's rules. Symmetries of conjugated ring systems are related to their electronic state by simple mathematical formulas. Description of lone pairs in conjugated systems is based on the strength and sign of orbital interactions around the ring. Simple models for bonding in copper clusters are tested, and the bonding of O 2 to Fe(II) in hemoglobin is described. Arguments made are supported by HF, B3LYP, and MP2 computations.

show abstract

Section: Vif Resonance Structures For Dative 3e/2c and 3-centered Bmentioning

confidence: 88%

Section: Three Dimensional Molecular Structural Formulasmentioning

confidence: 99%

Section: Vif Resonance Structures For Dative 3e/2c and 3-centered Bmentioning

confidence: 99%

“…The treatment here is inspired by Harcourt's approach utilizing Increased Valence structures [12]. See structures 24-29 in [12].…”

Section: Vif Description Of the Binding Of O 2 To Fe(ii)mentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Chemical Reasoning Based on an Invariance Property: Bond and Lone Pair Pictures in Quantum Structural Formulas

Alia

2010

Symmetry

View full text Add to dashboard Cite

show abstract

NSCl2−: Thiazyldichlorid - das Aza-Analogon von Thionyldichlorid

et al. 2001

View full text Add to dashboard Cite

Das „nackte“ ternäre Thiazyldichloridanion NSCl2− (siehe Bild) ist überraschend stabil und kann in Gegenwart eines großen Kations als Gegenion in makroskopischen Mengen hergestellt werden. Die Struktur wurde durch Röntgenbeugungsexperimente aufgeklärt und mit theoretisch berechneten Daten verglichen. Die zweifelsfreie Identifizierung wurde durch Raman‐, IR‐ und 14N/15N‐NMR‐spektroskopische Untersuchungen abgesichert. Die Struktur und die Bindungsverhältnisse werden auf der Basis von MO‐ und NBO‐Analysen diskutiert.

show abstract

NSCl2−: Thiazyl Dichloride—An Aza Analogue of Thionyl Dichloride

Keßenich

Kopp

Mayer

et al. 2001

Angew. Chem. Int. Ed.

View full text Add to dashboard Cite

The “naked” ternary thiazyl dichloride anion NSCl2− (see picture) is surprisingly stable and can be isolated on a macroscopic scale when a large countercation is present. The structure was determined by X‐ray diffraction and compared with theoretically obtained data. The unequivocal identification was supported by Raman, IR, and 14N/15N NMR spectroscopic studies. The structure and bonding are discussed on the basis of MO and NBO analysis.

show abstract

Increased-Valence Structures for Qualitative Valence-Bond Representations of Electronic Structure for Electron-Rich Molecules

Cited by 43 publications

References 89 publications

Chemical Reasoning Based on an Invariance Property: Bond and Lone Pair Pictures in Quantum Structural Formulas

Chemical Reasoning Based on an Invariance Property: Bond and Lone Pair Pictures in Quantum Structural Formulas

NSCl2−: Thiazyldichlorid - das Aza-Analogon von Thionyldichlorid

NSCl2−: Thiazyl Dichloride—An Aza Analogue of Thionyl Dichloride

Contact Info

Product

Resources

About