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Singlet Exciplexes between a Thioxanthone Derivative and Substituted Aromatic Quenchers: Role of the Resonance Integral

“…This behavior was thoroughly analyzed by Kuzmin. [53] However, this does not challenge the important conclusion ensuing from Figure 6: the present exciplex model is definitely supported by the good correlation between DG exc (estimated from the fit of kinetic data) and spectroscopic data (hDn fluo ).…”

Lifetimes of partial charge transfer exciplexes of 9-cyanophenanthrene and 9-cyanoanthracene

“…The measured values of s 0 are presented in Table 1 (6)) relative amplitude of the fast component of excited acceptor decay (a), exciplex lifetime s 0 0 (ns), degree of charge transfer in the exciplex (z) [13,14], ratio of emission rate constants k 0 F =k F and ratio of radiative transition dipole moments of exciplex and parent electron acceptor ( (5) and (7); (c) when s D were available at one value of [D] we have used the system of Eqs. (5) and (7) and a value of diffusion rate constant in the respective solvent [16,17] instead of k 1 . For all calculation, we used previously measured values of K SV [16,17].…”

“…(5) and (7) and a value of diffusion rate constant in the respective solvent [16,17] instead of k 1 . For all calculation, we used previously measured values of K SV [16,17]. The calculated values of s 0 0 , k 1 , k À1 and a are shown in Table 1.…”

“…An important feature of these exciplexes is a variable degree of charge transfer (z) which depends on both DG Ã ET and medium polarity [11][12][13][14] [1,2,15] and a nonlinear dependence of the exciplex emission frequency on the medium polarity [11][12][13][14][16][17][18][19]. These effects allow to evaluate z from experimental dependence the of the exciplex emission frequency on solvent polarity [11][12][13][14]16,17] or from the values of k 0 F ¼ ðu 0 =s 0 0 Þðu 0 =uÞ=ðu 0 =u À 1Þ (where u 0 and u are the fluorescence quantum yields of the exciplex and parent excited molecules in the presence of the quencher, respectively, u 0 is the fluorescence quantum yield of the parent excited molecules in the absence of quencher; s 0 0 is the exciplex lifetime) [1,2,11].…”

“…In this work, we have measured the lifetimes s (CA) and 9-cyanophenanthrene (CP) with electron donors -methoxybenzenes and 1,8-dimethylnaphthalene (À0:1 < DG Ã ET < 0:1 eV) whose emission quantum yields in the temperature range 200-380 K have been investigated earlier [16,17].…”