Restricted rotation involving the tetrahedral carbon. XX. Barriers to rotation and 13C NMR spectra of 9-(2-alkylphenyl) fluorene derivatives.

M Nakamura, N Nakamura, M Oki

Index: Nakamura,M. et al. Bulletin of the Chemical Society of Japan, 1977 , vol. 50, # 11 p. 2986 - 2990

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Citation Number: 32

Abstract

A series of 9-(2-alkylphenyl) fluorene derivatives are prepared and their internal rotation about the C 9–C ar bond is examined. Those which have a methyl, an ethyl, or an isopropyl group in 2′ position exist as a mixture of sp and ap forms, showing coalescence phenomena in the NMR spectra at high temperatures. The barriers to rotation of these compounds are obtained by the usual DNMR method. 9-(2-t-Butylphenyl) fluorene, in ...