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13C nmr of aryl substituted cations: the sigma-bridged coates cation and the 2-adamantyl cation

✍ Scribed by Donald G. Farnum; Thomas P. Clausen

Publisher: Elsevier Science
Year: 1981
Tongue: French
Weight: 211 KB
Volume: 22
Category: Article
ISSN: 0040-4039
DOI: 10.1016/s0040-4039(01)90151-0

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✦ Synopsis

A series of aryl substituted Coates and 2-adamantyl cations were generated and their 'jC NMR spectra determined to be consistent with sigma-bridged structures for the former, and unbridged structures for the latter. Of all the cations mentioned in the literature, the Coates cation (1) and some derivatives of it are the only systems which have been considered sigma bridged by all in the field.' Hence we decided to test our probe 2 for detecting bridged systems by correlating 13Ct chemical shifts of the aryl substituted Coates cations (2a-e) with the lsC+ chemical shifts of classical systems (such as (3)). The important results of this study are tabulated in Table 1.

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