Abstract

A range of electron-rich organic molecules has been intercalated into MoS₂ by the method of exfoliation–reflocculation. Intercalation produces an expansion of the lattice in a direction perpendicular to the dichalcogenide layers, the magnitude of which suggests that in the majority of cases, the guest adopts an orientation in which the molecular plane is parallel to the dichalcogenide layers. This is further supported by the suppression of the majority of the vibrational modes in the inelastic neutron scattering spectrum. The introduction of polar substituents to naphthalene favours a perpendicular orientation of the guest in the interlayer space, permitting a higher degree of organic incorporation. The electron transport properties of MoS₂ are modified by intercalation and materials containing naphthalene and alkylated derivatives exhibit anomalous behaviour at low temperatures. EXAFS data provide evidence for a structural distortion, involving the formation of cation chains, in the naphthalene intercalate.