TY - JOUR AU - Suffren, Yan AU - Zare, Davood AU - Eliseeva, Svetlana V. AU - Guénée, Laure AU - Nozary, Homayoun AU - Lathion, Timothée AU - Aboshyan-Sorgho, Lilit AU - Petoud, Stéphane AU - Hauser, Andreas AU - Piguet, Claude TI - Near-Infrared to Visible Light-Upconversion in Molecules: From Dream to Reality PY - 2013 JF - Journal of Physical Chemistry C JA - J. Phys. Chem. C SN - 1932-7447 VL - 117 IS - 51 SP - 26957 EP - 26963 L1 - http://pubs.acs.org/doi/pdf/10.1021/jp4107519 L2 - http://pubs.acs.org/doi/full/10.1021/jp4107519 L3 - http://pubs.acs.org/doi/abs/10.1021/jp4107519 L4 - http://www.unige.ch/sciences/chifi/publis/pics/double/ref01386.png M3 - 10.1021/jp4107519 UR - http://dx.doi.org/10.1021/jp4107519 N2 - Light-upconversion via stepwise energy transfer from a sensitizer to an activator exploits linear optics for converting low-energy infrared or near-infrared incident photons to higher energy emission occurring in the part of the electromagnetic spectrum ranging from visible to ultraviolet. Stepwise excitation is restricted to activators possessing intermediate long-lived excited states such as those found for trivalent lanthanide cations dispersed in solid-state matrices. When the activator is embedded in a molecular complex, efficient non-radiative relaxation processes usually reduce excited state lifetimes to such an extent that upconversion becomes too inefficient to be detected under practical excitation intensities. Theoretical considerations suggest that the combination of millisecond timescale sensitizers with a central lanthanide activator located in supramolecular complexes circumvents this bottleneck by creating a novel pathway reminiscent of the energy transfer upconversion mechanism observed in doped solids. Application of this novel concept to chromium/erbium pairs in discrete triple-stranded helicates demonstrates that strong-field trivalent chromium chromophores irradiated with near-infrared photons produce upconverted green erbium-centered emission both in the solid state and in solution. ID - 1386 ER -