Luminescence and Charge Transfer. Part 2. Aminomethyl Anthracene Derivatives as Fluorescent PET (Photoinduced Electron Transfer) Sensors for Protons
The importance of the modular structure 'fluor-spacer-amine' is pointed out for the design of fluorescent molecular sensors for pH according to the principle of photoinduced electron transfer (PET). Anthracen-9-yl methylamines (24) and some azacrown ether analogues (15 and 23) are examined in this context. They show pH-dependent fluorescence quantum yields describable by eqn. (5) while all other electronic spectral parameters remain essentially pH-invariant. The range of pKa values of these sensors are understandable in terms of macrocyclic effects and the transmission of electric fields across the anthracene short axis. Phase-shift fluorometric determination of the fluorescence lifetimes of these sensors allows the calculation of the rate constant of PET in their proton-free form to be 1010-1011 s-1, with the diamines 23 and 24b exhibiting the faster rates.
MSU Digital Commons Citation
Bissell, Richard A.; Calle, Emilio; De Silva, A. Prasanna; Desilva, Saliya; Gunaratne, H. Q.Nimal; Habib-Jiwan, Jean Louis; Peiris, S. L.Annesley; Rupasinghe, R. A.D.Dayasiri; Samarasinghe, T. K.Shantha D.; Sandanayake, K. R.A.Samankumara; and Soumillion, Jean Philippe, "Luminescence and Charge Transfer. Part 2. Aminomethyl Anthracene Derivatives as Fluorescent PET (Photoinduced Electron Transfer) Sensors for Protons" (1992). Department of Chemistry and Biochemistry Faculty Scholarship and Creative Works. 346.