* Thionyl chloride can engage in a range of different electrophilic addition reactions. It adds to alkenes in the presence of  to form an aluminium complex which can be hydrolysed to form a sulfinic acid. Both aryl sulfinyl chlorides and diaryl sulfoxides can be prepared from arenes through reaction with thionyl chloride in triflic acid or the presence of catalysts such as , ,  or .
* In the laboratory, a reaction between thionyl chloride and an excess of anhydrous alcohol can be used to produce anhydrous alcoholic solutions of HCl.
* Thionyl chloride undergoes halogen exchange reactions to give other thionyl species. 
:Reactions with fluorinating agents such as antimony trifluoride give thionyl fluoride:
: A reaction with hydrogen bromide gives thionyl bromide:
:Thionyl iodide can likewise be prepared by a reaction with potassium iodide, but is reported to be highly unstable.