Prototypal 1,2,3,5-dithia- and 1,2,3,5-diselenadiazolyl [HCN[sub 2]E[sub 2]] (E = S, Se). Molecular and electronic structures of the radicals and their dimers, by theory and experiment

The reactions of N,N,N[prime]-tris(trimethylsilyl)formamidine with ECl[sub 2] (E = S, Se) afford 1,2,3,5-dithia- and 1,2,3,5-diselenadiazolium chloride, which can be reduced with triphenylantimony to the corresponding dithia- and diselenadiazolyl radicals [HCN[sub 2]E[sub 2]]. The solid state struct...

Full description

Saved in:
Bibliographic Details
Published in:Journal of the American Chemical Society 1993-08, Vol.115:16
Main Authors: Cordes, A.W., Bryan, C.D., Davis, W.M., Laat, R.H. de, Goddard, J.D., Hicks, R.G., Kennepohl, D.K., Oakley, R.T., Glarum, S.H., Haddon, R.C.
Format: Article
Language:English
Subjects:
661300 > Other Aspects of Physical Science-- (1992-)
BINDING ENERGY
CHEMICAL REACTIONS
CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS
COHERENT SCATTERING
CRYSTAL STRUCTURE
DIFFRACTION
DIMERIZATION
DIMERS
ELECTRIC CONDUCTORS
ELECTRON SPIN RESONANCE
ELECTRONIC STRUCTURE
ENERGY
FORECASTING
INFRARED SPECTRA
INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY
IONIZATION POTENTIAL
MAGNETIC RESONANCE
MATHEMATICAL MODELS
MOLECULAR STRUCTURE
ORGANIC COMPOUNDS
ORGANIC SULFUR COMPOUNDS
POLYMERIZATION
RADICALS
RESONANCE
SCATTERING
SELENIUM COMPOUNDS
SPECTRA 400201 > Chemical & Physicochemical Properties
SYNTHESIS
X-RAY DIFFRACTION
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:The reactions of N,N,N[prime]-tris(trimethylsilyl)formamidine with ECl[sub 2] (E = S, Se) afford 1,2,3,5-dithia- and 1,2,3,5-diselenadiazolium chloride, which can be reduced with triphenylantimony to the corresponding dithia- and diselenadiazolyl radicals [HCN[sub 2]E[sub 2]]. The solid state structure of the cofacial dimer [HCN[sub 2]S[sub 2]][sub 2] has been determined by X-ray diffraction; crystals of [HCN[sub 2]S[sub 2]][sub 2] belong to the monoclinic space group P2[sub 1]/n, with a = 6.833(6), b = 16.463(4), c = 19.161(4) A, [beta] = 93.57(4)[degrees], FW = 210.30, Z = 12. The crystal structure consists of stacked dimers, with three dimers in the asymmetric unit. Along the stacking axis the mean intradimer S---S contact is 3.11 A; the mean interdimer contact is 3.76 A. Ab initio calculations with split-valence and larger basis sets have been employed to evaluate the structures and energies of both the gas phase radicals and their dimers. Minor changes in geometry are predicted upon association of the monomers; this relative structural invariance is consistent with low binding energies, the best predictions (including zero point vibrational energy corrections) being ca. 4 kcal/mol (for E = S) and ca. 10 kcal/mol (for E = Se). 30 refs., 6 figs., 9 tabs.
ISSN:0002-7863
1520-5126
DOI:10.1021/ja00069a022