Kinetic studies of the reactions of pentacyanonitrosylferrate(2−) with ligands containing acidic methylene groups

The increase in rates for the addition reactions of CH2LL′ (L, L′ = -CN, -CONH2; -CN, -CN; CH3CO-, CH3CO-) with pentacyanonitrosylferrate(2−) in basic solution to form Fe(CN)5N(O)CLL′4− complexes indicated that ⊖CHLL′ is the reactive species of the reactions. In addition to the pKa, the lability of the methylene protons of the ligands in aqueous solution also governs the reactivity of the reactions. The nitrosation products were rather unstable with respect to the dissociation into Fe(CN)5OH23- and oxime compounds.