Additions to Pyridinium Rings. II. Charge-Transfer Complexes as Intermediates

Investigation of the spectra of aqueous solutions of substituted 1-methylpyridinium iodides provides evidence that the new species, previously shown to be present in solutions of 1-methylpyridinium iodide itself, is a charge-transfer complex. Other cases where a charge-transfer complex may be present and where complex formation is essentially due to the “transfer” of an electron to a π-electron system containing a unit positive charge are discussed.