ISSN:
0009-2940
Keywords:
Sterically overcrowded trialkylammonium salt
;
Single-crystal structure
;
Protonation-energy hypersurface calculations
;
Chemistry
;
Inorganic Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
Structures and Molecular Properties of Sterically Overcrowded Molecules 43[1]. - Triisopropylammonium Chloride: Single-Crystal Structure and Calculations Concerning the Protonation of the p-Type Nitrogen Electron Pair[2]The protonation of triisopropylamine, which contains an almost planar NC3 skeleton of C3 symmetry and, therefore, a p-type N electron pair, with HCl in methanol causes severe structural perturbation due to extreme steric overcrowdedness: the single-crystal structure determination (orthorhombic Pbca, Z = 8) proves that the molecular symmetry is reduced to C5 by the rotation of one isopropyl group around its CN axis by almost 90° and the decrease of the angles CNC from 119° each to 115, 115 and 111°, respectively. The Cl⊖⃛(H)N hydrogen bond distance of 315 pm is presumably slightly increased by steric overlap of the van der Waals radii of Cl⊖ and one of the three adjacent methyl groups. The protonation of the p-type lone pair of triisopropylamine including the pyramidalization of the nitrogen centre and the twist of one isopropyl group can be simulated by a one-dimensional energy hypersurface calculation, if H⊕ attack outside the C3 axis is assumed.
Additional Material:
2 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/cber.19941270211
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