Other possibilities for the electrophile include (chloromethyl)oxonium cation (ClH2C–OH2+) or chlorocarbenium cation (ClCH2+), which may be formed in the presence of zinc chloride.
The text describes alternative electrophilic species that could participate in a reaction, specifically mentioning the (chloromethyl)oxonium cation (ClH2C–OH2+) and the chlorocarbenium cation (ClCH2+), which are formed when zinc chloride is present.