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

The kinetic studies of the addition reactions of pentacyanonitrosylferrate(2−) (NP) with acidic methylene ligands of the form CH2LL′ (L, L′ = –CN, –CONH2; –CN, –CN; CH3CO–, CH3CO–) have been carried out in basic solutions. The increase in the second order rate constants for the formation of Fe(CN)5N(O)CLL′4− complexes with the increase of OH− concentration indicated that ⊖CHLL′ is the reactive species of the reactions. In addition to the pK a, 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 View the MathML sourceFe(CN)5OH23- and oxime compounds. The kinetic measurements showed that the rates of dissociation were first order and were rather insensitive to the hydroxide concentration for the ligands under study.