Synthesis of copolymer based on naphthalene diimide connected with a non-conjugated flexible linker

We synthesized a copolymer in which segments of naphthalene diimide derivatives are connected by a short flexible linker that allow neighboring segments to interact closely with each other. Comparison of the optoelectronic properties of the copolymer and the monomer indicates weak intramolecular π–π interaction between NDI segments in the copolymer. Variable-temperature UV–vis absorption spectra measured in solution suggest a reversible change in the intramolecular interaction of the NDI segments in the polymers, implying a reversible conformation change.