The ion/molecule reactions of CCl3+ with acetophenones

► CCl3+ reacts with acetophenone in the gas-phase through three different channels. ► One of the main reaction products, C9H7Cl2O+, presents an interesting structural problem. ► IRMPD of C9H7Cl2O+ ions proceeds by loss of either Cl or CH3 in violation of the even-electron rule. ► Theoretical calculations and reactivity studies clearly show the formation of two isomeric C9H7Cl2O+ ions.