Fig. 7. Cryogenic IR spectra of peaks III vs. III* and IV vs. IV* observed in the ATDs of G1F, representing a mixture of the G1(α1-6)F and G1(α1-3)F positional isomers (foreground, peaks III and IV), and the synthesised G1(α1-6)F isomer (background, peaks III* and IV*) (see Fig. 6).