Mason Michael D, Ray Krishanu, Grober Robert D, Pohlers Gerd, Cameron James
Department of Applied Physics, Yale University, New Haven, Connecticut 06520, USA.
Phys Rev Lett. 2004 Aug 13;93(7):073004. doi: 10.1103/PhysRevLett.93.073004.
We report a method in which temperature dependent single-molecule fluorescence measurements are used to study the kinetics and thermodynamics of the acid-base interaction in films of photoresist polymer. We use the two distinct fluorescent prototropic forms of Coumarin 6 (C6-->C6+) to indicate the state of the acid-base system. Data are analyzed using a statistical model of the intensity probability distributions, yielding temperature dependent proton exchange rates, which is confirmed through agreement with a simple two-state Monte Carlo model. The temperature dependent rates are used to calculate the activation enthalpy for proton exchange.
