cz.wang1985

Purely organic materials with room-temperature phosphorescence (RTP) are currently under intense investigation because of their potential applications in sensing, imaging, and displaying. Inspired by certain organometallic systems, where ligand-localized phosphorescence (³π-π*) is mediated by ligand-to-metal or metal-to-ligand charge transfer (CT) states, we now show that donor-to-acceptor CT states from the same organic molecule can also mediate π-localized RTP. In the model system of N-substituted naphthalimides (NNIs), the relatively large energy gap between the NNI-localized ¹π-π* and ³π-π* states of the aromatic ring can be bridged by intramolecular CT states when the NNI is chemically modified with an electron donor. These NNI-based RTP materials can be easily conjugated to both synthetic and natural macromolecules, which can be used for RTP microscopy.

Purely organic: N-Substituted naphthalimides (NNIs) are purely organic materials that may show room-temperature phosphorescence (RTP). The relatively large energy gap between the NNI-localized ¹π-π* and ³π-π* states can be bridged by intramolecular charge transfer (CT) states when the NNI is chemically modified with an electron donor.