Journal ArticleDOI
Structure electronique des complexes acide‐base de Lewis. I. Structure electronique et conformation moléculaire des molécules F3P·BH3 et F2HP·BH3
J.-F. Labarre,C. Leibovici +1 more
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TLDR
In this paper, the electronic structure and preferred conformations of F3P·BH3 and F2HP·BNH3 were investigated in the framework of the CNDO/2 approximation.Abstract:
The electronic structure and preferred conformations of F3P·BH3 and F2HP·BH3 are investigated in the framework of the CNDO/2 approximation. In complete agreement with microwave data, the staggered conformations are predicted to be the most stable ones. The barriers to internal rotation are in good agreement with experimental values (F3P·BH3: calc. = 3.03 kcal/mole, exp. = 3.24 ± 0.15 kcal/mole; F2HP·BH3: calc. = 3.63 kcal/mole, exp. = 4.05 ± 0.45 kcal/mole) and a bicentric energy partitioning shows that the variations of the total energy are completely reflected by the only variation of the interaction energy between phosphorus and H atoms bonded to boron. The analysis of the electron densities reveals the importance of the 3s(P) → 2px(B) transfer in the formation of the co-ordination. Finally, the computed dipole moment value and direction agree with corresponding experimental data.read more
Citations
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Journal ArticleDOI
Une extension de la méthode CNDO/2 á l'étude des complexes d'éléments de transition
TL;DR: In this article, an extension of the CNDO/2 formalism, similar to the method of Clack, Hush and Yandle but with a different parametrisation, is proposed for investigating the electronic structure of transition metal complexes.
Book ChapterDOI
Barriers to Rotation and Inversion
Philip W. Payne,Leland C. Allen +1 more
TL;DR: Methods for analyzing ab initio wave functions to ascertain the physical origin of the barrier and provide a quantum mechanically well-defined, but simple picture of the mechanism have been more extensively developed for this topic than any other.
Journal ArticleDOI
Electron diffraction study and CNDO/2 calculations on the complex of aluminium trichloride with ammonia, Cl3Al.NH3
TL;DR: In this paper, the molecular geometry of the complex of aluminium trichloride with ammonia, Cl 3 Al, has been studied by electron diffraction and the most important internuclear distances in terms of r a parameters are as follows: r (Al-Cl) = 2.100±0.005 A, r(Al-N) = 1.996± 0.019 A, and r (Cl·Cl)= 3.569±
Journal ArticleDOI
On the conformational analysis of (CH3)3M (M = N, P, CH, SiH) molecules: CNDO/2 calculations versus experimental data. LEM or calder conformation?
M. Corosine,François Crasnier,Marie-Christine Labarre,Jean-François Labarre,Claude Leibovici +4 more
TL;DR: In this article, the theoretical energy minimum for the (60, 60, 60) -so-called LEM -conformation in which each methyl group is staggered with respect to the two opposite (MC) bonds is derived.
References
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Journal ArticleDOI
Application of the pople-santry-segal CNDO method to the cyclopropylcarbinyl and cyclobutyl cation and to bicyclobutane
TL;DR: In this article, the CNDO method has been applied to the cyclopropylcarbinyl and cyclobutyl cations, and has given results which are in very good accord with experimental data.
Journal ArticleDOI
Microwave Spectrum, Structure, Dipole Moment, and Barrier to Internal Rotation of Phosphorus Trifluoride—Borane
TL;DR: The microwave spectrum of several isotopic species of phosphorus trifluoride-borane (F3PBH3) has been measured and the following structural parameters determined: d(BH) = 1.207±0.008 A; d(PB) =1.836± 0.012 A; ∠HBH=115°04′±1°;
Journal ArticleDOI
Analyse conformationnelle theorique du cyclopropanecarbaldehyde, de la cyclopropylmethylcetone et des methyl-2 cyclopropyl-1 (methyl) cetones cis et trans
TL;DR: In this article, a SCF-LCAO-MO calculation was carried out on cyclopropylcarboxaldehyde (I, II and IV), cycloprocessyl-methylketone (II) and cis and trans-2-methylcyclopropylmethylketones (III and IV) for s-cis and s-trans conformations.
Journal ArticleDOI
Microwave spectrum, structure, and dipole moment of difluorophosphine borane.
TL;DR: In this paper, the structure of difluorophosphine borane (HF2P-BH3) has been determined from the microwave spectra of six isotopic species.
Journal ArticleDOI
An ab initio study of the bonding in phosphine borane, trifluorophosphine broane and trifluorophosphine oxide
I. H. Hillier,V. R. Saunders +1 more
TL;DR: Ab initio SCF-MO calculations on PH3BH3 and PF3O are described in this article, where the predominant mode of bonding involves σdonation from the phosphine with very little π-back-bonding.