No abstract

A donor-acceptor dyad system involving tetrathiafulvalene (TTF) as donor attached by a flexible spacer to perylene-3,4:9,10-bis(dicarboximide) (PDI) as acceptor was synthesized and characterized. The strategy used the preliminary synthesis of an unsymmetrical PDI unit bearing an alcohol functionality as anchor group. Single-crystal analysis revealed a highly organized arrangement in which all PDI molecules are packed in a noncentrosymmetrical pattern. It was shown that the fluorescence emission intensity of the TTF-PDI dyad can be reversibly tuned depending on the oxidation states of the TTF unit. This behavior is attributed to peculiar properties of TTF linked to a PDI acceptor, which fluoresces intrinsically. Consequently, this dyad can be considered as a new reversible fluorescence-redox dependent molecular system.

A series of perylene‐3,4:9,10‐bis(dicarboximide) (PBI) and perylene‐3,4:9,10‐bis(benzimidazole) (PTCBI) derivatives that are di‐ or tetra‐substituted at the bay region by electron‐donating or electron‐withdrawing groups have been synthesized as soluble n‐type semiconductors. Optical absorption spectroscopy and electrochemical analysis show that the nature of substitution at the bay region plays a crucial role in the modulation of the electronic properties of these PBI and PTCBI derivatives. Examination of these optical and electrochemical data in the light of energy levels identified by theoretical studies allowed a relationship between the structure and the electronic properties to be established.