Bare Molecular Anions of Unsaturated Hydrocarbons: Density Functional Charge and Spin Distributions Based on Their Single Crystal Structures

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Title:Bare Molecular Anions of Unsaturated Hydrocarbons: Density Functional Charge and Spin Distributions Based on Their Single Crystal Structures
Creators:
Havlas, Zdeněk
Bock, Hans
Journal or Publication Title:
Collection of Czechoslovak Chemical Communications, 63, 8, pp. 1245-1263
Uncontrolled Keywords:Radical ions, <i>Ab initio</i> calculations, Density functional theory, X-Ray diffraction, Hydrocarbon radical anions

Abstract

Bare π-hydrocarbon radical anions M<sup>•</sup>, dianions M<sup>−</sup> as well as even a radical trianion M<sup>•</sup> can be crystallized as alkali metal salts, [M<sup>(•)−<i>n</i></sup>][Me<sup>+</sup><sub>solv</sub>]<sub><i>n</i></sub> if the solvent-shared contact ion multiples, [M<sup>(•)−<i>n</i></sup>..(Me<sup>+</sup>)<sub><i>n</i></sub>]<sub>solv</sub>, present in aprotic solution after the reduction at an alkali metal mirror can be separated by advantageous cation solvation. Altogether 22 π-hydrocarbon anions M<sup>(•)−<i>n</i></sup> comprising polycyclic <i>cata</i>- as well as <i>peri</i>-annelated six-membered ring compounds, polyphenyls, those with nonalternant polycyclic skeletal topology, open chain and organosilicon derivatives have been characterized by low-temperature X-ray crystallographic analyses. Based on the structural data determined, their charge and spin populations have been approximated by density functional calculations including natural bond orbital analyses (DFT/NBO). Although in general the total (σ + π) charges at individual C centers of the hydrocarbon skeletons cannot be correlated neither with the structural data nor with the spin distribution, numerous interesting details as well as some useful rules are provided. They concern, for instance, central C-C bond elongation and peripheral C-C bond shortening, preferred charge localization patterns, effects of conformational changes in the π-radical anions crystallized or Jahn-Teller distortions of formally degenerate molecular radical anion states.

Title:Bare Molecular Anions of Unsaturated Hydrocarbons: Density Functional Charge and Spin Distributions Based on Their Single Crystal Structures
Creators:
Havlas, Zdeněk
Bock, Hans
Uncontrolled Keywords:Radical ions, <i>Ab initio</i> calculations, Density functional theory, X-Ray diffraction, Hydrocarbon radical anions
Divisions:Life and Chemical Sciences > Institute of Organic Chemistry and Biochemistry > Collection of Czechoslovak Chemical Communications
Journal or Publication Title:Collection of Czechoslovak Chemical Communications
Volume:63
Number:8
Page Range:pp. 1245-1263
ISSN:0010-0765
E-ISSN:1212-6950
Publisher:Institute of Organic Chemistry and Biochemistry
Related URLs:
URLURL Type
http://dx.doi.org/10.1135/cccc19981245UNSPECIFIED
ID Code:1378
Item Type:Article
Deposited On:06 Feb 2009 17:09
Last Modified:06 Feb 2009 16:09

Citation

Havlas, Zdeněk; Bock, Hans (1998) Bare Molecular Anions of Unsaturated Hydrocarbons: Density Functional Charge and Spin Distributions Based on Their Single Crystal Structures. Collection of Czechoslovak Chemical Communications, 63 (8). pp. 1245-1263. ISSN 0010-0765

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