Carbon–fluorine two-dimensional NMR correlation spectra

Abstract

Direct detection heteronuclear correlation (HETCOR) 13C{ 19F} and indirect detection gHMQC and gHSQC 19F{ 13C} two-dimensional correlation spectra have been compared for 1,3-perfluoro dimethylcyclohexane. Correlations to the geminally non-equivalent fluorine atoms in the CF 2 groups are more difficult to unambiguously observe using gHMQC or HETCOR in this typical cyclic fluorochemical in which 2 J FF ∼ > 1 J CF, but they are readily observed and assigned in the gHSQC experiment. Excellent 2D gHSQC 19F{ 13C} correlation spectra have also been obtained on H(CF 2) 4CH 2OH without proton decoupling, although half of the correlations within the several FH multiplets have zero intensity.