%0 Journal Article %A Aboshyan-Sorgho, Lilit %A Besnard, Céline %A Pattison, Phil %A Kittilstved, Kevin R. %A Aebischer, Annina %A Bünzli, Jean-Claude G. %A Hauser, Andreas %A Piguet, Claude %T Near-Infrared to Visible Light Upconversion in a Trinuclear d-f-d Complex %J Angewandte Chemie International Edition %@ 1433-7851 %V 50 %P 4108-4112 %D 2011 %K helical structures %K lanthanides %K photochemistry %K self-assembly %K upconversion %U http://onlinelibrary.wiley.com/doi/10.1002/anie.201100095/abstract;jsessionid=C352764B1E9229A45C8C5FB9AEA7917B.d02t01 %R 10.1002/anie.201100095 %U http://archive-ouverte.unige.ch/unige:15714 %X The connection of two CrIII sensitizers around a central ErIII acceptor in a self-assembled cation provides high local metal concentrations that favor efficient nonlinear energy transfer upconversion luminescence (see picture). Upon selective low-energy near-infrared irradiation of CrIII-centered transitions, 1 displays an unprecedented molecular two-photon upconverted green ErIII-centered emission.