Synthesis and Characterization of Donor‐Acceptor‐Donor Triads Containing Tetrathiafulvalene and Naphthalene Diimide Units: Towards Regulation of the Intermolecular Charge‐Transfer Interaction by Varying the Attached Side Groups

A series of donor‐acceptor‐donor triads 1–6 consisting of tetrathiafulvalene and naphthalene diimide units were synthesized and characterized. UV/Vis spectroscopic and cyclic voltammetric studies indicate that these triads show negligible intramolecular charge transfer interaction in the ground state. In contrast to that of the reference compound 36, their fluorescence intensities were reduced in the following sequences: 345612, which is probably due to photoinduced electron transfer in triads 1–6. Two solid forms (yellow and pen) of triads 1–5 were obtained, while only green form for triad 6 was obtained under the same conditions. Studies of the yellow and green forms with UV. XRD and DSC were performed. It was suggested that varying the attached side groups may regulate intermolecular charge transfer interactions in the solid state.