The study of relationship between chemical geometry and electronic configuration, non-Walsh type B Part II

Pakiari, A.H.; Nazari, Fariba

doi:10.1016/j.theochem.2004.11.023

Cited by 5 publications

(4 citation statements)

References 35 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Before that investigation, the D 3h geometries of all the AH 3 + ions (X = C, Si, Ge, Sn, Pb) had been taken for granted, as such species are expected to obey the Walsh rules for six valence electron compounds. [2] As a matter of fact, for CH 3 + the D 3h structure is the only energy minimum located at the highest levels of theory. [3] However, for the heaviest, Sn and Pb, the calculations show [1] and GeH 3 + are more stable than HSi + -(H 2 ) and HGe + -(H 2 ), the energy difference between the covalent structure and the ion-molecule complex substantially reduces from about 28 to about 10 kcal mol -1 passing from silicon to ger-3010 significantly more stable than F-AH 2 + (A = Sn and Pb).…”

Section: Introductionmentioning

confidence: 99%

“…1996, 118, 12154-12158) and found to possess, for A = Sn and Pb, energetically favoured HA + -(H 2 ) connectivities, the structural switch from covalent structures to ion-dipole complexes occurs, therefore, even earlier. This suggests that the "regular" covalent connectivity of even the simplest AH 2 X + or AHX 2 + cations of group XIV cannot be taken for granted, and, especially for germanium, tin and lead, the role of ionmolecule complexes must be carefully investigated. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006) manium.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Fluoromethyl Cations and Group XIV Congeners AH_nF_{3 – n}⁺ (A = Si, Ge, Sn, Pb; n = 0–2): From Covalent Structures to Ion‐Molecule Complexes

et al. 2006

View full text Add to dashboard Cite

Ab initio calculations at the MP2 and CCSD(T) level of theory (triple‐zeta quality basis sets for Si and Ge and effective core potentials plus DZ valence basis sets for tin and lead) have been performed to investigate the geometries, harmonic frequencies and relative stabilities of the (Si,H,F)+, (Ge,H,F)+, (Si,F3)+, (Ge,F3)+ and (A,Hn,F3 – n)+ (A = Si, Ge, Sn, Pb; n = 1 and 2) isomeric ions. While the H–Si–F+, F–SiH2+, H–SiF2+ and SiF3+ covalent structures are invariably predicted as the most stable isomers, the Ge+–(HF), FA+–(H2) and FA+–(HF) complexes (A = Ge, Sn, Pb) are the global minima on the potential energy surfaces, more stable than the corresponding covalent structures by up to some tens of kilocalories per mole. For tin and lead, the HA+–(HF) isomeric ions are also significantly more stable than F–AH2+ (A = Sn and Pb). Compared with the parent group XIV hydrides (A,H3)+, investigated so far by Schleyer and co‐workers (J. Am. Chem. Soc. 1996, 118, 12154–12158) and found to possess, for A = Sn and Pb, energetically favoured HA+–(H2) connectivities, the structural switch from covalent structures to ion‐dipole complexes occurs, therefore, even earlier. This suggests that the “regular” covalent connectivity of even the simplest AH2X+ or AHX2+ cations of group XIV cannot be taken for granted, and, especially for germanium, tin and lead, the role of ion‐molecule complexes must be carefully investigated. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)

show abstract

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Fluoromethyl Cations and Group XIV Congeners AH_nF_{3 – n}⁺ (A = Si, Ge, Sn, Pb; n = 0–2): From Covalent Structures to Ion‐Molecule Complexes

et al. 2006

View full text Add to dashboard Cite

show abstract

“…80,81 This approach focuses on the energetic benefit obtained when the geometry relaxes to minimize the electrostatic repulsion between electron pairs on the central atom X. An alternate simple approach is the applications of Walsh's rules, [82][83][84][85][86][87][88][89] which focus on how the energies of the occupied orbitals change with molecular shape and electronegativity differences. Walsh's rules also allow for the prediction of excitedstate properties, the analysis of which has been instrumental in the development of basic chemical understanding.…”

Section: Introductionmentioning

confidence: 99%

A unified diabatic description for electron transfer reactions, isomerization reactions, proton transfer reactions, and aromaticity

Reimers

McKemmish

McKenzie

et al. 2015

Phys. Chem. Chem. Phys.

View full text Add to dashboard Cite

While diabatic approaches are ubiquitous for the understanding of electron-transfer reactions and have been mooted as being of general relevance, alternate applications have not been able to unify the same wide range of observed spectroscopic and kinetic properties. The cause of this is identified as the fundamentally different orbital configurations involved: charge-transfer phenomena involve typically either 1 or 3 electrons in two orbitals whereas most reactions are typically closed shell. As a result, two vibrationally coupled electronic states depict charge-transfer scenarios whereas three coupled states arise for closed-shell reactions of non-degenerate molecules and seven states for the reactions implicated in the aromaticity of benzene. Previous diabatic treatments of closed-shell processes have considered only two arbitrarily chosen states as being critical, mapping these states to those for electron transfer. We show that such effective two-state diabatic models are feasible but involve renormalized electronic coupling and vibrational coupling parameters, with this renormalization being property dependent. With this caveat, diabatic models are shown to provide excellent descriptions of the spectroscopy and kinetics of the ammonia inversion reaction, proton transfer in N2H7(+), and aromaticity in benzene. This allows for the development of a single simple theory that can semi-quantitatively describe all of these chemical phenomena, as well as of course electron-transfer reactions. It forms a basis for understanding many technologically relevant aspects of chemical reactions, condensed-matter physics, chemical quantum entanglement, nanotechnology, and natural or artificial solar energy capture and conversion.

show abstract

“…The most fundamental approach to gaining insight into the structure of molecules like XY 3 series such as NH 3 to BiH 3 is by application of Walsh's Rules [220][221][222][223][224][225][226][227] using understanding of how occupied orbitals change with molecular shape and electronegativity differences. Excited state properties can also be framed in this context [221,228] and reaction symmetry understood, [229][230][231][232][233] but the close connectivity [139,[150][151][152][153][154]234,235] between ground-state and excited-state properties is lost.…”

mentioning

confidence: 99%

Putting David Craig’s Legacy to Work in Nanotechnology and Biotechnology

Reimers¹

2016

Aust. J. Chem.

View full text Add to dashboard Cite

left us with a lasting legacy concerning basic understanding of chemical spectroscopy and bonding. This is expressed in terms of some of the recent achievements of my own research career, with a focus on integration of Craig's theories with those of Noel Hush to solve fundamental problems in photosynthesis, molecular electronics (particularly in regard to the molecules synthesized by Maxwell Crossley), and self-assembled monolayer structure and function. Reviewed in particular is the relation of Craig's legacy to: the 50-year struggle to assign the visible absorption spectrum of arguably the world's most significant chromophore, chlorophyll; general theories for chemical bonding and structure extending Hush's adiabatic theory of electron-transfer processes; inelastic electron-tunnelling spectroscopy (IETS); chemical quantum entanglement and the Penrose-Hameroff model for quantum consciousness; synthetic design strategies for NMR quantum computing; Gibbs free-energy measurements and calculations for formation and polymorphism of organic self-assembled monolayers on graphite surfaces from organic solution; and understanding the basic chemical processes involved in the formation of gold surfaces and nanoparticles protected by sulfur-bound ligands, ligands whose form is that of Au 0 -thiyl rather than its commonly believed Au I -thiolate tautomer.

show abstract

The study of relationship between chemical geometry and electronic configuration, non-Walsh type B Part II

Cited by 5 publications

References 35 publications

Fluoromethyl Cations and Group XIV Congeners AH_nF_{3 – n}⁺ (A = Si, Ge, Sn, Pb; n = 0–2): From Covalent Structures to Ion‐Molecule Complexes

Fluoromethyl Cations and Group XIV Congeners AH_nF_{3 – n}⁺ (A = Si, Ge, Sn, Pb; n = 0–2): From Covalent Structures to Ion‐Molecule Complexes

A unified diabatic description for electron transfer reactions, isomerization reactions, proton transfer reactions, and aromaticity

Putting David Craig’s Legacy to Work in Nanotechnology and Biotechnology

Contact Info

Product

Resources

About

The study of relationship between chemical geometry and electronic configuration, non-Walsh type B Part II

Cited by 5 publications

References 35 publications

Fluoromethyl Cations and Group XIV Congeners AHnF3 – n+ (A = Si, Ge, Sn, Pb; n = 0–2): From Covalent Structures to Ion‐Molecule Complexes

Fluoromethyl Cations and Group XIV Congeners AHnF3 – n+ (A = Si, Ge, Sn, Pb; n = 0–2): From Covalent Structures to Ion‐Molecule Complexes

A unified diabatic description for electron transfer reactions, isomerization reactions, proton transfer reactions, and aromaticity

Putting David Craig’s Legacy to Work in Nanotechnology and Biotechnology

Contact Info

Product

Resources

About

Fluoromethyl Cations and Group XIV Congeners AH_nF_{3 – n}⁺ (A = Si, Ge, Sn, Pb; n = 0–2): From Covalent Structures to Ion‐Molecule Complexes

Fluoromethyl Cations and Group XIV Congeners AH_nF_{3 – n}⁺ (A = Si, Ge, Sn, Pb; n = 0–2): From Covalent Structures to Ion‐Molecule Complexes