Charge transfer in misfit layer chalcogenides, [(MX)(n)](1+x)(TX2)(m): a key for understanding their stability and properties

Stability of misfit layer chalcogenides (M.L.C.) is always governed by a ch arge transfer (C.T.) mechanism. A comparison between M.L.C. and parent inte rcalated layered binary systems shows comparable characteristics, which ill ustrate the role of electron donor for the MX part (or its corresponding A- intercalant species) towards the TX2 acceptor part. In that way, intercalat ion chemistry within the vdW gap of multilayered TX2 misfit derivatives is also considered. The donor character of the MX part, easy to understand whe n trivalent M cations are present, can be also assumed if a divalent M cati on is partly substituted for a trivalent one, as revealed from precise elec tron microprobe analysis. Examples of M.L.C. with enlarged MX part (with mi xed M+II, M+III) emphasize the reality of the C.T.. This M-to-T donor effec t necessarily controls the transport and intercalation properties.