Combining CeF4 and KSCN results in the formation of a highly orange-coloured solution immediately upon mixing in acetonitrile. Spectrum 2, top, reveals the appearance of a broad absorption band in the visible region, specifically at 350 and 480 nm, the latter tailing into the 500 nm region. However, in the reference reaction depicted in Scheme 9, thiocyanate failed to undergo oxidative activation followed by hydrogen atom abstraction on substrate 1 by cerium-LMCT (Table ). This observation may be attributed to ground-state redox complexation, wherein Ce 4+ is reduced to Ce 3+ . A comparison of the observed UV/Vis absorption upon the reaction of CeF4 with KSCN with the literature-reported spectrum of titration with isothiocyanate supports the hypothesis (Spectrum 2, bottom part).