Reductions involving more than one electron with formation of the M+ and [M+2H]+ ions were observed for electrosprayed meso-tris(N-methylpyridinium-4-yl)porphyrin iodides, MI3. These reductions were studied by using different solvents and flow rates. Formation of the [M+2H]+ ions occurred only for protic solvents and to a larger extent at lower flow rates. The type of the fourth substituent does not seem to affect the reduction processes. Formation of the two reduced species, M+ and [M+2H]+ ions, may occur through the participation of counter ion/solvent clusters. Reduction of multiply charged, non-metallated species with formation of [M+nH]+ ions (n > 1) was not observed before in positive mode electrospray mass spectrometry. © 2007 American Society for Mass Spectrometry.
Ramos, C. I. V., Santana Marques, M. G., Correia, A. J. F., Serra, V. V., Tomé, J. P. C., Tomé, A. C., … Cavaleiro, J. A. S. (2007). Reduction of Cationic Free-Base meso-Tris-N-Methylpyridinium-4-yl Porphyrins in Positive Mode Electrospray Ionization Mass Spectrometry. Journal of the American Society for Mass Spectrometry, 18(4), 762–768. https://doi.org/10.1016/j.jasms.2006.12.009