ON/OFF red emission from azaporphine in a coordination cage in water.
Red-emissive molecules have important applications as chemosensors, biological tags, and new light source materials but are severely limited by solubility and the tendency to form nonemissive aggregrates. Here we present an unusual example where a coordination cage sequesters and maintains the red-emissive properties of tetraazaporphine (TAP) in aqueous solution. Additionally, encapsulation within the highly cationic host lowers the pK(a) of the TAP interior protons, leading to the formation of an acid/base ON/OFF fluorescent switch.
Ono
Kosuke
K
Department of Applied Chemistry, School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan.
Klosterman
Jeremy K
JK
Yoshizawa
Michito
M
Sekiguchi
Kentaro
K
Tahara
Tahei
T
Fujita
Makoto
M
D003116:Color; D004396:Coloring Agents / Q000737:chemistry; D004583:Electrons; D009682:Magnetic Resonance Spectroscopy; D011166:Porphyrins / Q000737:chemistry*; D013056:Spectrophotometry, Ultraviolet; D014867:Water / Q000737:chemistry*
D004396:Coloring Agents; D011166:Porphyrins; D014867:Water; C107018:porphine