Abstract: Ion-neutral complexes(INCs) are the important intermediates in the gas phase unimolecular reactions. In recent twenty years, scientists from many countries have reported on a variety of INC-mediated fragmentation reactions in mass spectrometry including proton transfer reactions, cation transfer reactions and many kinds of isomerization reactions^1-4. In the multi-stage mass spectra of the protonated aromaticmethyl benzyl ethers and protonated sulfonamides, we observed a series of gas phase fragmentation reactions mediated by INC intermediates, including a new kind of charge-transfer reaction^5. The fragmentation pathways and the abundances of the product ions are both correlated with the substituent effect. These reactions are further systematically investigated by theoretical calculations and deuterium labeling experiments.