Fluorescence spectrum spectra

Figure Bl.1.4. Two-photon fluorescence excitation spectrum of naphthalene. Reprinted from [35], Courtesy, Tata McGraw-Hill Publishing Company Ltd, 7 West Patel Nagar, New Dehli, 110008, India.

An important extension to the simplest upconversion experiment at a single detection frequency M2 is the practice of measuring time-resolvedfluorescence spectra, that is, the shape of the fluorescence spectrum... 

Figure B2.3.15. Laser fluorescence excitation spectrum of the A S -X ff (1,3) band for the OH product, in the V = 3 vibrational level, from tire H + NO2 reaction [44]- (By pemrission from AIP.)...

The example of a X emission X-ray fluorescence spectrum of a solid sample of tin, shown in Figure 8.30, shows four prominent transitions. The method of labelling the transitions is, unfortunately, non-systematic but those in the lower-energy group are labelled a and the... 

Figure 9.29 Two-photon fluorescence excitation spectrum of 1,4-difluorobenzene. The upper and lower traces are obtained with plane and circularly polarized radiation, respectively, but the differences are not considered here. (Reproduced, with permission, Ifom Robey, M. J. and Schlag, E. W., Chem. Phys., 30, 9, 1978)...

Nevertheless, 1,4-difluorobenzene has a rich two-photon fluorescence excitation spectrum, shown in Figure 9.29. The position of the forbidden Og (labelled 0-0) band is shown. All the vibronic transitions observed in the band system are induced by non-totally symmetric vibrations, rather like the one-photon case of benzene discussed in Section 7.3.4.2(b). The two-photon transition moment may become non-zero when certain vibrations are excited. 

Electronic transitions in molecules in supersonic jets may be investigated by intersecting the jet with a tunable dye laser in the region of molecular flow and observing the total fluorescence intensity. As the laser is tuned across the absorption band system a fluorescence excitation spectrum results which strongly resembles the absorption spectrum. The spectrum... 

Figure 9.48 Part of the fluorescence excitation spectrum of 1,2,4,5-tetrafluorobenzene in a supersonic jet. (Reproduced, with permission, from Okuyama, K., Kakinuma, T, Fujii, M., Mikami, N. and Ito, M., J. Phys. Chem., 90, 3948, f986)...

Pyridin-2-one, 1-hydroxy-fluorescence spectrum, 2, 163 (81XL1515) Pyridin-2-one, 6-methoxy-pK 2, 151 <71JCS(B)289)... 

Thiophene, 2-phenyl-fluorescence spectrum, 4, 735 (7UOC2236) Thiophene, 2-propionyl-... 

Benzo[ghi]perylene (1,12-benzoperylene) [191-24-2] M 276,3, m 273°, 277-278.5°, 278-280°, Purified as light green crystals by recrystn from CfiH6 or xylene and sublimes at 320-340° and 0.05mm [UV Helv Chim Acta 42 2315 7959 Chem Ber 65 846 1932 Fluoresc. Spectrum J Chem Soc 3875 7954]. 1,3,5-Trinitrobenzene complex m 310-313° (deep red crystals from C6Hg) picrate m 267-270° (dark red crystals from CgH6) styphnate (2,4,6-trinitroresorcinol complex) m 234° (wine red crystals from CgH6). It recrystallises from propan-l-ol [J Chem Soc 466 7959]. 

Fig. 36. Laser fluorescence excitation spectrum of 7-azoindole dimer (6.1).

The optical train employed for photometric determinations of fluorescence depends on the problem involved. A spectral resolution of the emitted fluorescence is not necessary for quantitative determinations. The optical train sketched in Figure 22B can, therefore, be employed. If the fluorescence spectrum is to be determined the fluorescent light has to be analyzed into its component parts before reaching the detector (Fig. 28). A mercury or xenon lamp is used for excitation in such cases. 

In 1967 spraying with a solution of paraffin wax allowed the recording of the fluorescence spectrum of anthracene directly on the TLC plate without any difficulties [228]. Hellmann too was able to stabilize emissions by the addition of 2% paraffin to the solvent [229]. Low concentrations evidently serve primarily to stabilize the fluorescence — this stabilization concentration extends up to ca... 

Pfleiderer has suggested that the 7-hydroxy group exists as such in these compounds because this form is stabilized by mesomerism of type 191 (R — H). The tautomerism of 7-hydroxypteridine-2,4-dione in the excited electronic state has been studied on the basis of its fluorescence spectrum. 

In these special situations, other methods, such as electronic microscopy, IR spectrum, and fluorescence spectrum are to be used. 

The room temperature Raman spectrum excited in pre-resonance conditions [351 indeed shows bands at 169 cm-1 and 306 cm, which are in agreement with the modes observed in the fluorescence spectrum and that have been assigned by ab initio calculations to totally symmetric vibrations jl3). 

Tabic 6-5. Comparison of (he aK vibrational modes in the ground and excited states. The totally symmetric vibrations of the ground stale measured in tire Raman spectrum excited in pre-resonance conditions 3S] and in the fluorescence spectrum ]62 ate compared with the results of ab initio calculations [131- The corresponding vibrations in the excited stale arc measured in die absorption spectrum. 

Figure 6-22. Fluorescence exciuuon spectrum of a T() thin film detected at energies spanning from 15380 to 17300 cm-1. In this energy range the spectrum is unchanged.

The fluorescence spectrum of dibenz[7>,/]oxepin shows that this molecule adopts a planar structure in the excited state whereas the ground state has bent geometry as expected.19 The emission spectrum is similar to that of anthracene. 

Fig. 1.5 Fluorescence emission spectrum of the luciferase-oxyluciferin complex in the same solution as in Fig. 1.4 (solid line), compared with the luminescence spectrum of firefly luciferin measured in glycylglycine buffer, pH 7.6 (dotted line). The former curve from Gates and DeLuca, 1975 the latter from Selinger and McElroy, 1960, both with permission from Elsevier.

Fig. 3.1.4 Bioluminescence spectrum of Cypridina luciferin catalyzed by Cypridina luciferase (A), the fluorescence excitation spectrum of oxyluciferin in the presence of luciferase (B), the fluorescence emission spectrum of the same solution as B (C), and the absorption spectrum of oxyluciferin (D). The fluorescence of oxyluciferin alone and luciferase alone are negligibly weak. Measurement conditions A, luciferin (lpg/ml) plus a trace amount of luciferase in 20 mM sodium phosphate buffer, pH 7.2, containing 0.2 M NaCl B and C, oxyluciferin (20 pM) plus luciferase (0.2mg/ml) in 20 mM sodium phosphate buffer, pH 7.2, containing 0.2 M NaCl D, oxyluciferin (41 pM) in 20 mM Tris-HCl buffer, pH 7.6, containing 0.2 M NaCl. All are at 20°C.

According to Charbonneau et al. (1985), aequorin is a single chain peptide consisting of 189 amino acid residues, with an unblocked amino terminal. The molecule contains three cysteine residues and three EF-hand Ca2+-binding domains. The absorption spectra of aequorin and BFP are shown in Fig. 4.1.3, together with the luminescence spectrum of aequorin and the fluorescence spectrum of BFP. 

Fig. 4.1.3 Absorption spectra of aequorin (A), spent solution of aequorin after Ca2+-triggered luminescence (B), and the chromophore of aequorin (C). Fluorescence emission spectrum of the spent solution of aequorin after Ca2+-triggered bioluminescence, excited at 340 nm (D). Luminescence spectrum of aequorin triggered with Ca2+ (E). Curve C is a differential spectrum between aequorin and the protein residue (Shimomura et al., 1974b) protein concentration 0.5 mg/ml for A and B, 1.0 mg/ml for C. From Shimomura and Johnson, 1976.

Fig. 4.1.16 Luminescence spectrum of aequorin triggered by Ca2+ (solid line /.max 465 nm), and the fluorescence spectra of Aequorea GFP excitation (dashed line A.max 400 nm and 477 nm) and emission (dash-dot line 7max 509 nm). The dotted line is the fluorescence excitation spectrum of GFP in the light organs, showing that 480 nm excitation peak is almost missing — an evidence showing that GFP in light organs exists in an aggregated form having a very low E value at 480 nm.

Fig. 4.2.2 Left panel-. Uncorrected Ca2+-triggered bioluminescence spectrum of W92F obelin derived from O. longissima. Right panel Corrected bioluminescence spectrum of the same obelin (dotted line), and the fluorescence emission spectrum of the spent solution after luminescence (solid line). From Deng et al., 2001, with permission of the Federation of the European Biochemical Societies.

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