Mazengo, Richard (1968) Optical stability and spectroscopic studies of 1,1-binaphthyl and related compounds.
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Previous work on tlie optical stabilities of substituted 1,1'-binaphthyls has shown that the energy of activation for the racemisation of optically active 1,1'-binaphtliyls with Planar substituents in the 8,8- positions is almost identical with that of unsubstituted 1,1'-binaphthyl. 8'-Methyl-1,1'-binaphthyl-8-carboxylic acid has been prepared, resolved and its Arrhenius parameters and transition state theory functions for racemisation determined. The values of , and A S are remarkably close to those of 8-methyl-1,1'-binaphthyl and it is concluded that here again the -COOH group offers a negligible steric barrier to the transition state for racemisation.Optically active 2,2'-dimethyl-1,1'-binaphthyl has been synthesised and found to be highly optically stable; this is explained on the basis that its ground state energy is much lower than that of an 8,8'-substituted 1,1'-binaphthyl.Attention was then turned to an investigation of the ground states of certain of the substituted 1,1'-binaphthyls using , mass spectra, O.R.D. and C.D. Ultraviolet spectra indicate that the 8,8'-substituted 1,1'-binaphthyls are overall more "planar" than 2,2'-substituted 1,1'-binaphthyls. Nuclear magnetic resonance spectra indicate that the substituents in the 2,2'- positions are further away
This is a Accepted version This version's date is: 1968 This item is not peer reviewed
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Deposited by () on 31-Jan-2017 in Royal Holloway Research Online.Last modified on 31-Jan-2017
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