However, the overall NOE pattern at 230 K clearly reflects the overall aggregated ion pair structure and indicates that there is not a single complex structure formed but that multiple complexes are present, and potential both chlorine and fluorine act as hydrogen bond acceptors in the H-TEDA(BF 4 ) 2 / SF ® complex (see Figure and SI, Figure ). The general downstream mechanism of the H-TEDA(BF 4 ) 2 -induced fluorination reactions resembles that