Charge-transfer matrixes as a tool to desorb intact labile molecules by matrix-assisted laser desorption/ionization. Use of 2,7-dimethoxynaphthalene in the ionization of polymetallic porphyrins.

2,7-Dimethoxynaphthalene (DMN) is proposed as matrix to investigate the structure of polymetallic porphyrins through matrix-assisted laser desorption/ionization tandem time-of-flight experiments. The peculiarity of DMN is represented by the formation of molecular radical cations and of some diagnostic fragments only. The traditional matrixes do not afford the expected molecular species. The experiments have been performed on extremely labile species such as zinc porphyirinate complexes with aluminum and gallium quinolinate to prove the softness of the methodology.