Resonance Raman excitation

Champion P M and Albrecht A C 1981 On the modeling of absorption band shapes and resonance Raman excitation profiles Chem. Phys. Lett. 82 410-13... 

Remade F and Levine R D 1993 Time domain information from resonant Raman excitation profiles a direct inversion by maximum entropy J. Chem. Phys. 99 4908-25... 

Kung C Y, Chang B-Y, Kittrell C, Johnson B R and Kinsey J L 1993 Continuously scanned resonant Raman excitation profiles for iodobenzene excited in the B continuum J. Phys. Chem. 97 2228-35... 

These observations implicating the role of zeaxanthin in the formation of the 535 nm band have prompted us to test the nature of this absorption feature using the resonance Raman excitation near its maximum (argon line at 528.7 nm). Figure 7.11a presents the v, resonance Raman spectral... 

The analysis of carotenoid identity, conformation, and binding in vivo should allow further progress to be made in understanding of the functions of these pigments in the photosynthetic machinery. One of the obvious steps toward improvement could be the use of continuously tuneable laser systems in order to obtain more detailed resonance Raman excitation profiles (Sashima et al 2000). This technique will be suitable for the investigation of in vivo systems with more complex carotenoid composition. In addition, this method may be applied for the determination of the energy of forbidden Sj or 2 Ag transition. This is an important parameter, since it allows an assessment of the energy transfer relationship between the carotenoids and chlorophylls within the antenna complex. 

Sashima, T., Koyama, Y., Yamada, T., and Hashimoto, H. 2000. The lBu+, lBu", and 2Ag" energies of crystalline lycopene, P-carotene, and mini-9-P-carotene as determined by resonance-Raman excitation profiles Dependence of the I IUi state energy on the conjugation length../. Phys. Chem. B 104 5011-5019. 

Sashima, T., M. Shiba, H. Hashimoto, H. Nagae, and Y Koyama. 1999. The 2A energy of crystalline aR-trans-spheroidene as determined by resonance-Raman excitation profiles. Chem. Phys. Lett. 290 36 42. 

The resonance Raman excitation profiles are shown in Figures 8, 9 and 10. The radical modes clearly peak with the electronic transition of Ru(bpy) at ca. 360 nm (Figure 8), demonstrating a bpy 7T 7T assignment for this absorption. The neutral bpy... 

Figure 3-21 Comparison of TCNQ - electronic absorption spectrum and resonance Raman excitation profiles, (a) Electronic absorption spectrum from 15,000 to 17,850 cm-1. The extinction coefficient, e, scale is normalized with respect to e at 663.0nm (15,083cm-1) = 3.0 x 103M-Icm-1. (b) Superposition of the v2 (2,192cm-1). v4 (1,389cm-1), v5 (1,195cm-1) and V9 (336 cm-1) excitation profiles. The relative intensity scale has been scaled to 0.00 to lO.Ofor all four spectra. (Reproduced with permission from Ref. 76. Copyright 1976 American Chemical Society.)...

An alternative assignment for the bands observed in neutral [M(dithiolene)3] complexes has been proposed, and is based upon resonance Raman excitation profiles (317). However, we should first briefly discuss specific aspects of the observed vibrational Raman spectra for metallo-tris(dithiolenes). Group theory dictates that the vibrational modes of [M(dithiolene)3]° 1 2 complexes in Dy, and /J3 are... 

This initial report was followed closely by the UV resonance Raman spectra of uridine (UMP), cytidine (CMP) and guanidine (GMP) monophosphates by Nishimura, et al. [149] and the application of UV resonance Raman spectroscopy to nucleic acids and their components started in earnest. In the years that followed, Peticolas and Spiro provided much of the research effort in this area. For nucleosides and nucleotides, Peticolas studied guanosine [150], UMP [151-154], GMP [152, 155], AMP [144, 152, 156] and CMP [153], Spiro was the only one to measure the UV resonance Raman spectra of TMP, in addition to those of all the other naturally occurring nucleotides [157, 158], For all of these nucleotides, UV resonance Raman excitation profiles have been determined. 

A few of these UV resonance Raman studies have reported excitation profiles of oligonucleotides [158, 177], These studies show that the hypochromism in the resonance Raman intensities can be as large as 65% for bands enhanced by the ca. 260 nm absorption band for poly(dG-dC) and that the hypochromism can vary substantially between vibrational modes [177], In the duplex oligonucleotide poly(rA)-poly(rU) [158], similar hypochromism is seen. Although theUV resonance Raman excitation profiles of oligonucleotides have been measured, no excited-state structural dynamics have been extracted from them. 

Thus far, only one report of the UV resonance Raman excitation profiles of nucleic acids has appeared in the literature. The excitation profiles of calf thymus DNA [177] shows the same hypochromism as that observed in both single-stranded and duplex oligonucleotides. Also as expected, the excitation profiles are quite complex. Although an excitation profile is obtained for every vibrational mode, numerous bases are contributing to the Raman intensity observed in every vibration, each in its own microenvironment. Thus, the resonance Raman intensities currently are not useful for elucidating the excited-state structural dynamics of nucleic acids. 

A further area which had attracted an increasing amount of attention is that of the resonance Raman spectra of structurally simple inorganic molecules, particularly those possessing allowed electronic transitions in the visible region. Clark (1975) and Clark and Dines (1986) have reviewed the application of resonance Raman excitation in inorganic chemistry. 

The assigmnent of a less intense electronic absorption of oxyHr near 500 mn (e 2000 M cm per diiron site) as a peroxo n Fe charge transfer transition has also withstood rigorous scmtiny. Resonance Raman excitation within this absorphon band led to the discovery of an 0-0 stretching frequency at 844 cm . Isotope labeling studies showed unequivocally that this frequency was due to the bound O2 and also identified the corresponding Fe-02 stretching... 

Biswas, N., and Umapathy, S. (1995). Wavepacket dynamical studies on trans-azabenzene absorption spectrum and resonance Raman excitation profiles in the n-Jt transition. Chem. Phys. Lett. 236, 24-29. 

C. Analysis of distortions from resonance Raman excitation profiles... 

Wavenumber/cm Fignre 3. Relationship between the resonance Raman excitation profiles (top) and the resonance Raman spectra (middle and bottom). See text for details. 

C. Analysis of Distortions from Resonance Raman Excitation... 

Figure 26. Calculated and experimental resonance Raman excitation profiles of ( ). v2(A), VjfO), 2v,(0), and (vj + VjX ) for Rh2(02CCH3)4(PPhj)2. From Ref. 5 with permission from the American Chemical Society.

Figure 30. Calculated and experimental resonance Raman excitation profiles of V, ( ), vjfA), Vj(tX-sensXO)- <5(OCOXO), 2v, ( ), (A), (v, + vjK )- + vj( ), for...

Figure 35. Calculated and experimental (KBr disc, approx. 80 K) resonance Raman excitation profiles of v,(n), VjiO), and V3 >) and v iA) for Cs3[Re20Cl,o]. From Ref. 6 with permission from the American Chemical Society.

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