The electronic structure of N2O4. II. The 'π-only' structure

1965 ◽  
Vol 18 (12) ◽  
pp. 1885 ◽  
Author(s):  
RD Brown ◽  
RD Harcourt

Molecular orbital studies for the "π-only" electronic structure for N2O4 are presented. They indicate that such a structure is unsatisfactory because it (i) implies a paramagnetic ground state for the molecule, (ii) predicts incorrect trends in NO bond lengths, strengths, and ONO angles, and (iii) is of considerably higher energy than an alternative structure previously described. It also would seem to imply a non-planar conformation for the molecule.

1966 ◽  
Vol 19 (9) ◽  
pp. 1567 ◽  
Author(s):  
RD Brown ◽  
EK Nunn

A VESCF molecular-orbital study of the electronic structure of the triiodide anion in its crystalline environment in caesium triiodide and in tetraphenylarsonium triiodide reveals the effect of the lattices upon the electronic structures. The calculated total valence-electron energy as a function of the position of the central iodine nucleus provides an understanding of the observed geometries of the anion in the two crystals. The energy plot also implies that the asymmetric stretch of the triiodide is strongly anharmonic in the crystal. A satisfactory correlation exists between observed iodine : iodine bond lengths and computed bond orders.


Author(s):  
C. A. Coulson

The molecular-orbital method has been applied to a study of in its ground state and excited levels, and the relative importance of the perturbation and variational methods has been considered in some detail, as well as the effect of certain integrals which, in discussions of molecular structure, have often been neglected. It appears that the ion should exist in stable equilateral form with a nuclear distance about 0·85 Å., and that all excited levels are unstable.Reasons are given for supposing that the molecule H3 is linear and not triangular.


2020 ◽  
Vol 3 (1) ◽  
pp. 20
Author(s):  
Valentina Ferraro ◽  
Marco Bortoluzzi

The influence of copper(I) halides CuX (X = Cl, Br, I) on the electronic structure of N,N′-diisopropylcarbodiimide (DICDI) and N,N′-dicyclohexylcarbodiimide (DCC) was investigated by means of computational DFT (density functional theory) methods. The coordination of the considered carbodiimides occurs by one of the nitrogen atoms, with the formation of linear complexes having a general formula of [CuX(carbodiimide)]. Besides varying the carbon–nitrogen bond lengths, the thermodynamically favourable interaction with Cu(I) reduces the electron density on the carbodiimides and alters the energies of the (NCN)-centred, unoccupied orbitals. A small dependence of these effects on the choice of the halide was observable. The computed Fukui functions suggested negligible interaction of Cu(I) with incoming nucleophiles, and the reactivity of carbodiimides was altered by coordination mainly because of the increased electrophilicity of the {NCN} fragments.


2021 ◽  
Author(s):  
Stephen Sproules

The electronic structures of homovalent [V2(μ-S2)2(R2dtc)4] (R = Et, iBu) and mixed-valent [V2(μ-S2)2(R2dtc)4]+ are reported here. The soft-donor, eight-coordinate ligand shell combined with the fully delocalised ground state provides a...


2014 ◽  
Vol 895 ◽  
pp. 420-423 ◽  
Author(s):  
Sathya Sheela Subramanian ◽  
Baskaran Natesan

Structural optimization, magnetic ground state and electronic structure calculations of tetragonal PbMnO3have been carried out using local density approximation (LDA) implementations of density functional theory (DFT). Structural optimizations were done on tetragonal P4mm (non-centrosymmetric) and P4/mmm (centrosymmetric) structures using experimental lattice parameters and our results indicate that P4mm is more stable than P4/mmm. In order to determine the stable magnetic ground state of PbMnO3, total energies for different magnetic configurations such as nonmagnetic (NM), ferromagnetic (FM) and antiferromagnetic (AFM) were computed for both P4mm and P4/mmm structures. The total energy results reveal that the FM non-centrosymmetric structure is found to be the most stable magnetic ground state. The electronic band structure, density of states (DOS) and the electron localization function (ELF) were calculated for the stable FM structure. ELF revealed the distorted non-centrosymmetric structure. The band structure and DOS for the majority spins of FM PbMnO3showed no band gap at the Fermi level. However, a gap opens up at the Fermi level in minority spin channel suggesting that it could be a half-metal and a potential spintronic candidate.


2009 ◽  
Vol 48 (16) ◽  
pp. 7750-7764 ◽  
Author(s):  
Kevin R. Kittilstved ◽  
Lilit Aboshyan Sorgho ◽  
Nahid Amstutz ◽  
Philip L.W. Tregenna-Piggott ◽  
Andreas Hauser

1982 ◽  
Vol 60 (6) ◽  
pp. 730-734 ◽  
Author(s):  
Russell J. Boyd ◽  
Jeffrey P. Szabo

Abinitio molecular orbital calculations are reported for several cyclic and acyclic sulfones. The geometries of XSO2Y, where X, Y = H, F, or CH3 are optimized at the STO-3G* level. Similar calculations are reported for the smallest cyclic sulfone, thiirane-1,1 -dioxide, as well as the corresponding sulfoxide, thiirane-1-oxide, and the parent sulfide, thiirane. Where comparison with experiment is possible, the agreement is satisfactory. In order to consider the possibility of substantial differences between axial and equatorial S—O bonds in the gas phase, as observed in the crystal structure of 5H,8H-dibenzo[d,f][1,2]-dithiocin-1,1-dioxide, STO-3G* calculations are reported for a six-membered ring, thiane-1,1-dioxide, and a model eight-membered ring. Limited geometry optimization of the axial and equatorial S—O bonds in the chair conformations of the six- and eight-membered rings leads to bond lengths of 1.46 Å with the difference being less than 0.01 Å.


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