Used as a reagent in organic synthesis, particularly in the preparation of quinolinium salts for antimicrobial and antimalarial research. It serves as a phase-transfer catalyst in certain alkylation reactions due to its ability to facilitate ion transfer between aqueous and organic phases. Also employed in the development of dyes and fluorescent probes, where its quinoline backbone enhances photostability and light absorption properties. Its iodide component allows for easy displacement in nucleophilic substitution reactions, making it useful in the synthesis of more complex heterocyclic compounds.