Reactions of (di)manganese carbonyl ions with 1,4,7-trimethyl-1,4,7-triazacyclononane (Me3TACN) in the gas phase

The gas-phase reactions of a series of (di)manganese carbonyl positive ions with 1,4,7-trimethyl-1,4,7-triazacyclononane (Me(3)TACN) have been examined with the aid of Fourier transform ion cyclotron resonance (FTICR) mass spectrometry. The monomanganese carbonyl ions, Mn(CO)(n)](+) (n = 2-5), react predominantly by ligand exchange and to a minor extent by electron transfer with the formation of the radical cation of Me(3)TACN. For the Mn(CO)(n)](+) (n = 2-4) ions, the ligand exchange results in the exclusive formation of a Mn(Me(3)TACN)](+) complex, whereas small amounts of Mn(CO)(Me(3)TACN)](+) ions are also generated in the reactions of the Mn(CO)(5)](+) ion. The Mn(2)(CO)(n)](+) ions (n = 2, 4 and 5) react also by competing electron transfer and ligand exchange. The reaction of the Mn(2)(CO)(2)](+) and Mn(2)(CO)(4)](+) ions is associated with cleavage of the Mn--Mn bond as evidenced by the pronounced formation of Mn(Me(3)TACN)](+) ions. For Mn(2)(CO)(5)](+), the ligand exchange leads mainly to the formation of Mn(2)(CO)(n)(Me(3)TACN)](+) (n = 1-3) ions. These primary product ions react subsequently by the incorporation of a second Me(3)TACN molecule to afford Mn(2)(CO)(Me(3)TACN)(2)](+) and Mn(2)(CO)(2)(Me(3)TACN)(2)](+) ions. Both of these latter species incorporate an oxygen molecule with formation of ions with the assigned composition of Mn(2)(O(2))(CO)(Me(3)TACN)(2)](+) and Mn(2)(O(2))(CO)(2)(Me(3)TACN)(2)](+).