Triplet state properties

For the investigation of triplet state properties a laser flash photolysis apparatus was used. The excitation source was a Lambda Physik 1 M 50A nitrogen laser which furnished pulses of 3.5 ns half-width and 2 mJ energy. The fluorescence decay times were measured with the phase fluorimeter developed by Hauser et al. (11). 

Prat F, Stackow R, Bernstein R et al. (1999) Triplet-state properties and singlet oxygen generation in a homologous series of functionalized fullerene derivatives. J Phys Chem. 103 7230-7235. 

K. Ugurbil, A. H. Maki, and R. Bersohn, Study of the triplet state properties of tyrosines and tryptophan in azurins using optically detected magnetic resonance, Biochemistry 16, 901-907 (1977). 

Organic Molecules in their Triplet States, Properties and Reactions of... 

The lowest excited triplet state in anthryl-oligothiophenes (634) were studied (96CPL(260)125). Also, binaphthyl oligothiophenes have been studied (09MM1710). The triplet state properties are studied with respect to coupling effects between the molecular subunits for a different chain length n and also for additional pyridine substitution (635). 

Spin-orbit coupling not only governs the amount and pattern of ZFS of the emitting triplet state, but it is also of dominant importance for the radiative emission decay rates and thus for the photoluminescence quantum yields. These properties are crucial for the suitability of triplet emitters in OLEDs. In conclusion, detailed spectroscopic studies of compounds triplet state properties in combination with... 

Natural sunlight induced photooxidation of naphthalene in aqueous solution has also been reported by McConkey et al. to produce six major products including 1-naphthol, coumarin, and two hydroxyquinone [9]. The authors proposed that the initially formed 2 + 2 and 2 + 4 photo cyclo addition products undergo subsequent oxidation and/or rearrangement to form the observed products [9]. Grabner et al. have studied solvent effects on the photophysics of naphthalene and report that fluorescence lifetime decreases by a factor of 2.5 in aqueous solution compared to organic solvents (e.g. ethanol, hexane, acetonitrile) [10]. Based on the observed differences in naphthalene excited triplet state properties in aqueous and organic media, the decrease... 

Triplet states of xanthone depend upon the composition of the solvent the presence of water enhances the yield of 2 un state Dual phosphorescence from 2-(2 -hydroxyphenyl) benzoxazole is due to keto-enol tautomerism and the kinetics multi-exponential decay is due to differences of environment . Triplet state properties and triplet state-oxygen interactions of the biologically interesting linear and angular furocoumarins are useful in view of possible clinical application . 

Photochemical and Spectroscopic Properties of (NichoIIs and Leermakers). Organic Molecules in their Triplet States, Properties and Reactions of (Wagner... 

Both Garcia et al. [4,28] and Elisei et al. [29] also investigated the triplet-state properties, including the triplet-state extinction coefficients (e-p), lifetimes (tj) and quantum yields (<2>t), of several 2-substituted, 10-alkylated phenothiazine derivatives. The 7 values were determined from the respective maximum triplet absorbances by using the energy-transfer method to energy acceptors, either merocyanine-540 (MC 540) in deaerated methanol and acetonitrile, or to fi-carotene in deaerated acetonitrile or benzene. These 7... 

It is not often that the triplet state properties of cofacial dimers are reported but, in an interesting variation on the normal theme, this has been done for a series of naphthalenophanes. Here, the triplet state is accessed via sensitization with benzophenone and it is shown that the excited state behaviour depends markedly on the conformation of the superstructure. Both monomer and excimer states are apparent in the transient absorption records, according to the extent of... 

Metalloporphyrins and related compounds continue to attract attention as photosensitizers and as building blocks for construction of artificial lightharvesting arrays. The photophysical properties of several structurally modified porphyrins have been measured with a view to identifying new sensitizers for use in photodynamic therapy. The triplet state properties of porphyrins adsorbed onto the outer surface of vesicles have been describedand the fluorescence spectral properties of some amphiphilic porphyrins have been recorded. Similar studies have been carried out with halogenated tetraar-... 

Interest in the triplet state is not as active nor are there as many diverse developments as is the case for excited singlet states. There is less detailed spectroscopic work on triplet state properties and biological involvement is not extensive although the photosensitizer systems mentioned in the previous section operate largely through triplet state intermediates. 

Buckminsterfullerene (C q) has not escaped the attention of photochemists. Determination of luminescence and absorption spectra of 60 films has made some excited state assignments possible for this molecule. Some work has also been reported on the triplet state properties. 

Wagnert L, Rubin R, Berg A, Mahammed A, Gross Z, Levanon H (2010) Photoexcited triplet state properties of brominated and non-brominated Ga(III)-corroles as studied by time-resolved electron paramagnetic resonance. J Phys Chem B 114 14303-14308... 

Table 12.5 Triplet State Properties of Some Drugs Studied Using Laser Flash Photolysis Technique...

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