Novel antennae for the sensitization of near infrared luminescent lanthanide cations

Near Infrared (NIR) luminescence is useful for many applications ranging from lasers, telecommunication to biological imaging. We have a special interest for applications in biological media since NIR photons have less interference with such samples. NIR photons can penetrate relatively deeply in tissues and cause less damage to biological samples. The use of NIR luminescence also results in improved detection sensitivity due to low background emission. The lower scattering of NIR photons results in improved image resolution. NIR emitting lanthanide compounds are promising for imaging because of their unique properties such as sharp emission bands, long luminescence lifetimes and photostability. Here, we review our efforts to develop novel sensitizers for NIR emitting lanthanides. We have employed two global strategies: (1) monometallic lanthanide complexes based on derivatives of salophen, tropolonate, azulene and pyridine; and (2) polymetallic lanthanide compounds based on nanocrystals, metal-organic frameworks and dendrimers complexes.