Bonding in H3AB compounds

1985 ◽  
Vol 63 (7) ◽  
pp. 1609-1615 ◽  
Author(s):  
Michael W. Schmidt ◽  
Mark S. Gordon
Keyword(s):  
Phosphine Oxide ◽  
Valence Electron ◽  
Amine Oxide ◽  
Localized Orbitals ◽  
Ionic Complexes ◽  
Hartree Fock ◽  
Synthetic Target ◽  
Phosphine Sulfide

The nature of binding in the 14 valence electron H3AB molecules is examined, where A and B are taken from the second and third rows. The AB bonding is inferred from the computed structures, d orbital populations, and localized orbitals. Near Hartree–Fock results are reported for the strongest bonding compounds, which are those with third row atoms A, and second row atoms B. Phosphine oxide, and to a lesser extent phosphine sulfide, are found to be effectively doubly bound. Amine oxide and sulfide are found to be ionic complexes. The thiazyl bond is confirmed as triple in nature. The exotic compound F3IC is proposed as a synthetic target.

Compton Profiles and Nature of Bonding in Tantalum Chalcogenides

2013 ◽  
Vol 209 ◽  
pp. 143-146
Author(s):  
K.C. Bhamu ◽  
Arvind Sharma ◽  
Asvin R. Jani ◽  
B.L. Ahuja
Keyword(s):  
Linear Combination ◽  
Density Functional ◽  
Valence Electron ◽  
Population Analysis ◽  
Theoretical Data ◽  
Hartree Fock ◽  
Line Shapes ◽  
Valence Electron Density ◽  
Γ Ray ◽  
Gaussian Orbitals

Abstract. We report the Compton profiles of tantalum chalcogenides (TaS2 and TaSSe) using Hartree–Fock and hybridization of Hartree–Fock and density functional theories within linear combination of atomic (Gaussian) orbitals. To interpret the theoretical data on Compton line shapes, we have measured the Compton profiles using our in-house 100 mCi 241Am γ-ray Compton spectrometer. To understand the relative nature of bonding, we have obtained the equal-valence-electron-density (EVED) profiles. The EVED profiles shows that charge in TaSSe is more localized than TaS2 in the bonding direction which confirms that TaSSe is more covalent than TaS2, which is in agreement with the Mulliken’s population analysis.

scholarly journals Phosphinsubstituierte Chelatliganden, III [1] η5-Cyclopentadienyleisencarbonyl-Koraplexe mit Thiocarbamoylphosphin-, -phosphinsulfid- und -phosphinoxid-Liganden / Phosphine Substituted Chelate Ligands, III [1] η5 -Cyclopentadienyliron Carbonyl Complexes with Thiocarbamoyl-Phosphine, -Phosphine Sulfide and -Phosphine Oxide Ligands

1981 ◽  
Vol 36 (12) ◽  
pp. 1588-1594 ◽  
Author(s):  
Udo Kunze ◽  
Antonios Antoniadis
Keyword(s):  
Nucleophilic Substitution ◽  
Phosphine Oxide ◽  
Room Temperature ◽  
Carbonyl Complexes ◽  
Chelate Complexes ◽  
Significant Dependence ◽  
Chelate Ligands ◽  
Phosphine Sulfide

The reactions of N-silylated and free diphenylphosphino thioformaraides, Ph2PC(S)NRR′ (R = Ph, Me, Et; R′ = Me3Si, H), with CpFe(CO)2l yield, by displacement of one equiva­lent CO, both red-brown P,S-coordinated chelate complexes 1 a-c and green P-coordinated iodo complexes 2a-c. With thiocarbamoylphosphine sulfides, Ph2P(S)C(S)NHR (R = Ph, Me), the S,S′-coordinated chelate complexes 3a, b are obtained. The corresponding phos­phine oxides only form deeply coloured, weak 1/1 adducts 4a, b with CpFe(CO)2l. The course of the nucleophilic substitution of CpFe(CO)2X (X = Cl, Br, I) by N-silyl phosphino thioformamides reveals a significant dependence on the halogen employed. For X = Cl, elimination of RNCS and formation of the cationic diiron complex [CpFe(CO)2]2_ PPh2+Cl- (5 a) takes place, whereas for X = Br no reaction occurs at room temperature. Mechanistic reasons for this unexpected behaviour are discussed.

Frozen core approximation for atoms and atomic ions

1968 ◽  
Vol 46 (23) ◽  
pp. 2675-2678 ◽  
Author(s):  
R. P. McEachran ◽  
C. E. Tull ◽  
M. Cohen
Keyword(s):  
Valence Electron ◽  
Atomic Systems ◽  
Atomic Ions ◽  
Hartree Fock ◽  
Core Approximation

Properties of the frozen core approximation for atomic systems containing one valence electron in addition to completely filled shells are derived. It is shown that, in addition to computational convenience, the procedure enjoys certain theoretical advantages over the standard Hartree–Fock approximation.

Influence of relativistic valence-core correlation on p-state fine structure in some univalent systems

1981 ◽  
Vol 59 (6) ◽  
pp. 769-774 ◽  
Author(s):  
J. Migdalek ◽  
W. E. Baylis
Keyword(s):  
Fine Structure ◽  
Valence Electron ◽  
Closed Shell ◽  
Polarization Potential ◽  
Atomic Core ◽  
Hartree Fock ◽  
The Core ◽  
Ab Initio Approach ◽  
The One ◽  
Single Configuration

Single-configuration relativistic Hartree–Fock values of fine-structure separations are calculated for p-levels in systems with a single electron outside a closed-shell core, both with and without allowance for relaxation and polarization of the core. Effects of the polarization of the atomic core by the valence electron are included by the addition of a polarization potential to the one-electron Hamiltonian. The results obtained generally compare well with available experimental data and indicate a significant influence of core polarization on fine-structure splittings. Contributions of the relaxation of the core are considerable only for the heavier systems. The choice of the cut-off parameter r0 in the polarization potential, as well as of the shape of the cut-off function, and the success of the ab initio approach are discussed. It is suggested that for indium and thallium, in contrast to the case for rubidium, silver, and gold, the simplified picture of a core plus a single valence electron is no longer entirely satisfactory.

Sign in / Sign up

Export Citation Format

Share Document