Nitric oxide reactivity of a manganese(II) complex leading to nitrosation of the ligand

• Ligand used for the present study is L [L = N1,N2-bis((pyridine-2-yl)methyl)ethane-1,2-diamine].
• Two manganese(II) complexes, [Mn(L)(Cl)2], 1 and [Mn(L)(H2O)2](ClO4)2, 2 were prepared.
• In acetonitrile solution, complex 1 did not react with nitric oxide.
• Complex 2 in acetonitrile reacts with NO to afford Mn(II)-nitrosyl followed by the reduction of Mn(II).
• The reduction was found to accompany with simultaneous N-nitrosation of the ligand.

Manganese(II) complexes, [Mn(L)(Cl)2], 1 and [Mn(L)(H2O)2](ClO4)2, 2 {L = N1,N2-bis((pyridine-2-yl)methyl)ethane-1,2-diamine} were prepared and characterized. In acetonitrile solution, complex 1 did not react with nitric oxide gas. However, addition of nitric oxide gas to the acetonitrile solution of complex 2 resulted in unstable Mn(II)-nitrosyl intermediate. The formation of nitrosyl intermediate was evidenced by UV–Vis, solution FT-IR, 1H NMR spectral studies. Subsequently, Mn(II) center in the complex 2 was undergone reduction to Mn(I) with a simultaneous N-nitrosation of the ligand. The N-nitrosated ligand was isolated and characterized. It should be noted that the corresponding Cu(II) complex of the same ligand in presence of nitric oxide was not found to yield Cu(II)-nitrosyl.

Nitric oxide reactivity of two manganese(II) complexes, [Mn(L)(Cl)2], 1 and [Mn(L)(H2O)2](ClO4)2, 2 {L = N1,N2-bis((pyridine-2-yl)methyl)ethane-1,2-diamine} were studied. In acetonitrile solution, complex 1 did not react with nitric oxide gas. Addition of nitric oxide gas to the acetonitrile solution of complex 2 resulted in unstable Mn(II)-nitrosyl intermediate prior to the reduction of Mn(II) to Mn(I) with a simultaneous N-nitrosation of the ligand.Figure optionsDownload as PowerPoint slide