Photophysical data

The cyanine dye Hterature has been reviewed (2,11—19). Ref. 12 is the best source for the heterocycHc chemistry of cyanine and related dyes. Several new syntheses and many new dye stmctures are discussed in later reviews (13,16) combined with compilations of physical and photophysical data (16,17). 

If the "localized" formulation of the structure of Ru(bpy)3 as Ru(III)(bpy)2(bpy ) + is realistic, the resonance Raman spectrum of Ru(bpy)3+ can be predicted. A set of seven prominent symmetric modes should be observed at approximately the frequencies seen in Ru(III)(bpy)3, with approximately two thirds of the intensity of the ground state bpy modes. The intensity of the isolated 1609 cm - peak fits this prediction, as do the other "unshifted" peaks. A second set of seven prominent Raman modes at frequencies approximating those of bpy should also be observed. Figure 6 shows that this prediction is correct. The seven Ru(bpy)3+ peaks which show substantial (average 60 cm l) shifts from the ground state frequencies may be correlated one-for-one with peaks of Li+(bpy ) with an average deviation of 10 cm. In addition, the weak 1370 cm l mode in Ru(bpy)3 is correlated with a bpy mode at 1351 cnfl. It is somewhat uncertain whether the 1486 cm l bpy mode should be correlated with the Ru(bpy)3 mode at 1500 cm -1- or 1482 cm 1. It appears clear that the proper formulation of Ru(bpy)3 is Ru(III)(bpy)2(bpy ). This conclusion requires reinterpretation of a large volume of photophysical data (43,45,51 and references therein). 

From photophysical data recorded for the series of complexes [Ru(4,4 -Me2bpy)3] [Ru(4,4 -... 

Table 3 Photophysical data of selected osmium(VI) 0x0 and nitrido complexes in acetonitrile at room...

Table 3 Photophysical data for 8-PhOH-purine adducts...

Unfortunately, the procedure just described to determine C(t) can consume many hours of spectrometer time, since several transients must be acquired and processed. Recently, an alternative timesaving procedure for measuring C(t) was developed [23,31], The procedure, which is approximate, requires a single emission transient and certain photophysical data on the probe. It is based on a simple photodynamic model, in which it is assumed that the spectrum of the probe is a simple function of a single solvent parameter, X, denoted as the solvent polarization. During the solvation process, X is time-dependent, such that C(t) = [X(t) — A (oo))]/ [X(0) - X(oo)]. 

Table 4 presents comprehensive photophysical data of 2T-7T (di-n-butyl), including singlet oxygen quantum yields (4>a) in benzene. Considering the absorption and emission spectra, there is a relatively small effect of solvent on these maxima. In the fluorescence excitation spectra, there is a considerable red shift, 1600 cm-1, in the maxima with an excellent linear correlation between 1/n and the maximum of the first transition, as well as the 0-0 energy particularly for 4T-7T. 

These data plus photophysical results indicate that 2T, and even 3T, are not yet legitimate representatives of a polythiophene and that such a representation seemingly begins with 4T. However, additional consideration of all the photophysical data indicates that the first true representative of a polythiophene is 5T. 

Table 7 Photophysical Data of Monomeric Fullerene/y-CD and Fullerene/Surfactant Complexes in Aqueous Media...

Table 1 Photophysical data for key representative platinum complexes that are emissive in solution at room temperature... 

Consequently, the luminescence is assigned unambiguously to the presence of aurophilic interactions. The photophysical data obtained for these alkylisocyanides gold(I) complexes are presented in Table 11. 

TABLE 11. Photophysical Data for (RNC)Au NC Complexes in the Solid State at 298 K... 

TABLE 1., Optical and Photophysical Data for Platinum(II) Metallopolyynes ... 

TABLE 2. Photophysical data of model compound 1, monomers of la—li and polymers la li... 

Photophysical data of polymers 2a-2h are summarized inTable 5. Polymers 2a-2h exhibit similar absorption spectra in DMF solution. Three absorption bands, with Xmax at 280—309, 311-358, and 408—427 nm, respectively, are observed. For example, 2a shows strong absorption bands at 315 and 351 nm (a = 34.6 and 23.1 dm3 g 1 cm-1, accordingly) and one moderate band at 408 nm, which is absent in the free ligand (4,4 -methylene-/ff,v-[2-(7V-phenylformimidoyl) phenol]). The high-energy absorption bands are assigned to spin-allowed singlet... 

Kumar et al., 2005). In turn the Judd-Ofelt parameters were calculated and the radiative lifetime estimated from eqs. (14)—(18). It is noteworthy that Judd-Ofelt parameters reproduce the observed spectra well. Photophysical data are listed in table 19 along with the emission cross section and the lifetime of the Er(4Ii3/2) level. The emission spectra were obtained by exci-... 

To date, only the simplest member of the oligo(phospholylenevinylidene) family, namely derivative 62 (Scheme 4.17), is known [47b]. This compound can be obtained in high yield, as the E-isomer, by a McMurry coupling with aldehyde 61 (Scheme 4.17) [47b]. Note that the use of Ti salts is compatible with the presence of g3-P centers. No photophysical data for the orange mixed phosphole-ethenyl derivative 62 have been reported. 

Table 4.3 Optimum electropolymerization potentials of monomers 35-37, p-doping and n-doping potential ranges (V) and photophysical data for the corresponding dedoped polymers.

Photophysical Data of Selected Osmium(VI) Oxo and Nitrido Complexes in Acetonitrile at Room Temperature... 

Table 1. Room temperature electrochemical and photophysical data for homoleptic ru-...

Table 19 Photophysical data for mixed thiophene-phosphole derivatives (Amax and Agm in nm, quantum yield determined using fluorescein as standard) <2003OL3467>...

Table 20 Photophysical data for dithieno[3,2-fa 2, 3 -d]phosphole derivatives (Amax and Aem in nm, quantum yieid <1> determined using quinine sulfate as standard)...

Photophysical characteristics of Pis (Scheme 12.1), especially the quantum yields of their dissociation O iss, are very important. Most of the photophysical data were measured by nanoseconds or picoseconds laser flash photolysis (LFP) or phosphorescence at low temperature. The properties of representative Pis are given in Table 12.1. 

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