Electrospray mass spectrometry studies of purified aluminum tridecamer in 50:50 water/methanol mixture

This study conducted electrospray ionization mass spectrometry (ESI-MS) tests on 90–95% pure aluminum tridecamer (Al13) salt dissolved in a 50:50 (v/v) water/methanol mixture. The mass spectra for water/methanol mixture revealed no major characteristic peaks for Al13, but showed a few series with incremental difference of 32u, 18u (or 9u), and 14u in the m/z = 200–500 regime. The methanol molecule typically replaces one by one the ligated aqua ligand and adducts to the aluminum center to destruct aluminum tridecamer into smaller, singly or doubly charged polymeric species. A species network with ligand substitution and addition reactions was for the first time revealed.