A. Legon, J. Tizard, Z. Kisiel
Jul 17, 2002
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Influential Citations
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Journal
Journal of Molecular Structure
Abstract
Abstract The rotational spectra of the parent isotopomer of the symmetric-top molecule 1-fluoroadamantane and each of its four different singly substituted 13 C species have been observed by pulsed-jet Fourier transform microwave spectroscopy. The spectrum of the parent isotopomer was also investigated in the millimetre-wave region to allow high- J transitions to be observed in order to determine accurately the very small centrifugal distortion constants D J and D JK . The rotational constants of these isotopomers were used to establish the r s and the mean r 0 geometries for the carbon atom skeleton. The first of these indicated a bridgehead compression that was confirmed by ab initio calculations. The preferred geometry for the adamantyl cage is that of r 0 quality obtained by fitting the moments of inertia of all five isotopomers investigated in combination with the ab initio geometry appropriately scaled. The three unique values of r (CC) are 1.527, 1.541, and 1.540 A, with increasing distance from the substituted bridgehead atom, respectively, and r( CF )=1.402 A .