Nygaard, Sune; Leung, Ken C.-F.; Aprahamian, Ivan; Ikeda, Taichi; Saha, Sourav; Laursen, Bo W.; Kim, Soo-Young; Hansen, Stinne W.; Stein, Paul C.; Flood, Amar H.; Stoddart, J. Fraser; Jeppesen, Jan O. Journal of the American Chemical Society, 2007 , vol. 129, # 4 p. 960 - 970