Vapor Deposition of Naphthalenediimides Having Vinyl Groups

Naphthalenediimide (NDI) derivatives without or with one or two vinyl groups were synthesized to prepare thin films by the vapor deposition. NDI with larger number of vinyl substitution tends to form thin films with poorer crystallinity and lower electrical conductivity. On the other hand, the vinyl modification is effective in improving film morphology and temporal stability. Electron-assisted deposition of the vinyl-substituted NDIs produces smooth and stable amorphous polymer films with a lower conductivity. The vinyl substitution brings about contradictory effects of improving film morphology and stability at a cost of reducing crystallinity and conductivity. The vinyl modification also enables controlling the film/substrate interface by covalent tethering via a self-assembled monolayer.