Using OCCCCCCCCOCc1ccc(F)c(F)c1, O=[Cr](=O)([O-])O[Cr](=O)(=O)[O-] to produce O=C(O)CCCCCCCOCc1ccc(F)c(F)c1, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.