“…The most evident observation was a marked shielding of the 19 F NMR chemical shifts in fluorochromarenes by 30-50 ppm relative to the free arenes. 32,33 Moreover, there is clear electronic interaction between the rings. Typically, (Z 6 -C 6 F 6 )Cr(Z 6 -C 6 H 6 ) exhibits binomial septets in both the 19 F and 1 H NMR regimes with an inter-ring J HF coupling constant of 1.44 Hz.…”