Fluorine deshielding in the proximity of a methyl group. An experimental and theoretical study
作者:Gordon W. Gribble、Daniel J. Keavy、Erik R. Olson、Ian D. Rae、Alfred Staffa、Tomas E. Herr、Marta B. Ferraro、Rubén H. Contreras
DOI:10.1002/mrc.1260290504
日期:1991.5
19F chemicalshifts are reported for a series of alkyl‐substituted fluoronaphthalenes and related compounds that exhibit steric crowding around the fluorine atom due to the proximity of methyl groups. Comparisons of these chemicalshifts with others measured in similar compounds but without the corresponding methyl groups show that this crowding effect produces a large low‐field shift of the 19F signal