The Kinetics and Mechanism of Reactions Between the Nitroprusside Ion and Secondary Amines

Abstract

The kinetics of the reactions of the nitroprusside ion — pentacyanonitrosylferrate(II) — with various secondary amines have been studied in basic media. Two parallel reaction pathways are involved: (i) the reaction of the nitroprusside ion with hydroxyl ions to form Fe(CN)5NO4+2, in which NO−2 is then replaced by the amine; and (ii) the reaction of the nitroprusside ion with two molecules of amine to form the corresponding nitrosamine and the complex Fe(CN)5NHR3‐2. The corresponding rate equations have been obtained and explained by proposed reaction mechanisms. We propose a concerted mechanism for reaction (ii) in which the amine binds the nitrosyl group at the same time as the amine proton is removed by a base catalyst. The resulting nitrosamine complex subsequently undergoes substitution by the amine in a faster step.

Stabilization of Aliphatic and Aromatic Diazonium Ions by Coordination: An Experimental and Theoretical Study

“…If this strategy is to be followed, the coordinated nitrosyl has to be electrophilic enough as to react with amines. Reactions of [Ru(bpy) 2 (NO)Cl] 2+ and [Fe(CN) 5 NO] 2- involving primary − and secondary amines as well as amino acids have been studied in the past only in aqueous media, where enormous amounts of nucleophile are present in the form of hydroxide or water molecules.…”

Performing Organic Chemistry with Inorganic Compounds: Electrophilic Reactivity of Selected Nitrosyl Complexes

“…Until a few years ago, reactions of pentacyanonitrosylferrate(II) involving primary , and secondary amines as well as amino acids had only been studied in aqueous media, where enormous amounts of nucleophiles are present in the form of hydroxide ions or water molecules. Our group has focused on reactions conducted in nonaqueous (organic) solvents, in an attempt to get more insight into the chemistry of coordinated diazonium ions and also to elucidate the possible role of pentacyanonitrosylferrate(II) as a nitrosating agent in lipophilic media.…”