Charge transfer in graphite nitrate and the ionic salt model

Fractional charge transfer is studied from both chemical and electronic property standpoints in graphite intercalated with nitric acid. NO2 byproduct is analyzed quantitatively by optical absorption, and H2O byproduct is observed qualitatively, consistent with 2HNO3 →N2O5+H2O; N2O5→NO2+ (oxidizes graphite) + NO3− (intercalates). The compond is found to contain one NO3− per four neutral HNO3. Metallic reflectivity data is consistent with one free hole per 5 total intercalated entities, indicating that each charge transferred from graphite to acid results in a free hole, as required by the ionic salt model.