Resonance Raman in platinum phthalocyanine

1978 ◽  
Vol 56 (7) ◽  
pp. 976-984 ◽  
Author(s):  
Tzer-Hsiang Huang ◽  
Klaus E. Rieckhoff ◽  
Eva-Maria Voigt
Keyword(s):  
Absorption Maximum ◽  
Lower Energy ◽  
Mixed Solvents ◽  
Resonance Raman ◽  
Visible Region ◽  
Excited Singlet ◽  
Absorption Region ◽  
The Third ◽  
Resonance Raman Spectra ◽  
Platinum Phthalocyanine

The resonance Raman spectra and excitation profiles of platinum phthalocyanine (PtPc) in α-chloronaphthalene (α-ClN) and in mixtures of α-ClN and n-octane were obtained at 295 K with excitation from 660 to 570 nm covering the total lower energy absorption region of PtPc. Eighteen fundamentals and overtone-combinations were observed. Our data show that the third absorption maximum of PtPc in the visible region is actually the (0–1), but not the (0–2) as previously interpreted, transition. The (0–1) bands in the excitation profiles of most resonance-enhanced-vibrations were found to be more intense and frequency shifted compared with their counterparts in absorption. Based on the depolarization ratios, we deduced the symmetry of PtPc in α-ClN in the excited singlets to be D2h, C2v, or D2; no differences were found in the mixed solvents. The small Stokes loss observed in the absorption spectra, as well as the absence of the (0–2) maxima in the excitation profiles, indicate that the equilibrium position of the first excited singlet is only slightly different from that of the ground state.

The Resonance Raman Microprobe Detection of Single Bacterial Cells from a Chromobacterial Mixture

1987 ◽  
Vol 41 (2) ◽  
pp. 241-244 ◽  
Author(s):  
R. A. Dalterio ◽  
M. Baek ◽  
W. H. Nelson ◽  
D. Britt ◽  
J. F. Sperry ◽  
...  
Keyword(s):  
Raman Spectra ◽  
Resonance Raman ◽  
Visible Region ◽  
Argon Laser ◽  
Bacterial Cells ◽  
Raman Microprobe ◽  
Resonance Raman Spectra ◽  
Bacterial Mixtures ◽  
Television Image ◽  
Excited Resonance

High-quality resonance Raman spectra in the visible region can be obtained from very small aggregates of chromobacteria, and very useful spectra can be obtained from individual cells. Individual cells in bacterial mixtures have been clearly identified by argon-laser-excited resonance Raman spectra taken with a commercially available Spex Micramate. Organisms present in the vicinity of the laser beam and in the beam itself can be observed and counted with ease by means of a television image obtained via a vidicon tube attached to a microscope. The method appears capable of identification at the species level.

Identification of the tautomeric structure of H2TMpyP4–DNA complexes from resonance Raman excitation profiles

1992 ◽  
Vol 70 (9) ◽  
pp. 2413-2419
Author(s):  
Liu Yixian ◽  
J. A. Koningstein ◽  
Y. Yevdokimov
Keyword(s):  
Resonance Raman ◽  
Normal Modes ◽  
Raman Intensity ◽  
Absorption Region ◽  
Buffer Solutions ◽  
Bending Mode ◽  
Resonance Raman Spectra ◽  
Raman Excitation Profiles ◽  
Dna Complex ◽  
Soret Absorption

Aspects of the electronic structure of tautomers of tetrakis(N-methyl-4-pyridyl)porphyrin (H2TMpyP4) complexed to DNA have been determined from a study of the resonance Raman excitation profiles of normal modes of H2TMpyP4 in buffer solutions containing monomeric and aggregated molecules and of a H2TMpyP4/DNA complex with r(c) ~ 25. Maxima of the excitation profiles of the complex have been assigned to electronic origins for transitions between the ground state and states in the Soret absorption region of intercalated and externally groove-bound tautomers of H2TMpyP4. The positions of the electronic origins support the assignment of the CD spectrum of the complex. From the shift of the Cβ—H bending mode of the selectively excited resonance Raman spectra of tautomers of the porphyrin molecules it can be concluded that the pyridyl rings of externally bound H2TMpyP4 molecules are twisted to a lesser degree than those rings for intercalated H2TMpyP4. Raman intensity studies also reveal that the resonance-enhanced Raman intensity of modes of aggregated H2TMpyP4 is greater than those of the monomer.

scholarly journals Resonanz-Raman-Effekt von Thiocyanatkomplexen einiger Übergangsmetalle

1970 ◽  
Vol 25 (10) ◽  
pp. 1394-1400 ◽  
Author(s):  
W. Krasser ◽  
H. W. Nürnberg
Keyword(s):  
Raman Spectrum ◽  
Infrared Spectra ◽  
High Intensity ◽  
High Frequency ◽  
Resonance Raman ◽  
Ammonium Salts ◽  
Iron Cobalt ◽  
Decay Products ◽  
Thiocyanate Complexes ◽  
Resonance Raman Spectra

Abstract The thiocyanates of the transition metals iron, cobalt, copper as well as of rhenium and of tech-netium appear in solution as strongly coloured complexes. The resonance raman bands in the sol-vent acetonitrile are investigated. To achieve an unambiguous identification the infrared spectra were recorded too. The change in position and structure of the acetonitrile bands indicates strong complexation of iron, cobalt and copper with acetonitrile, thus indicating the existence of mixed acetonitrile-thiocyanate complexes. The resonance raman spectra of the rhenium-and technetium-thiocyanates present as tetramethyl ammonium salts show however no raman-and infrared-bands of complexed acetonitrile molecules.In the raman spectrum of the thiocyanates of iron, cobalt and copper mainly the totally sym-metric C≡N, S-C, Me-S and Me-N valence vibrations are observed, among which the S-C vibration shows a remarkably high intensity. Besides, a series of bands is obtained which is inter-preted partly as caused by decay products, and partly as bands of complexed acetonitrile. The thiocyanates of rhenium and of technetium show the three possible valence vibrations only. The high frequency of the S-C valence indicates the N-coordination of the thiocyanate group.

scholarly journals Low-temperature resonance-Raman spectra of Japanese-lacquer-tree (Rhus vernicifera) laccase, type-2-copper-depleted laccase and H2O2-treated type-2-copper-depleted laccase

1983 ◽  
Vol 213 (2) ◽  
pp. 503-506 ◽  
Author(s):  
G Musci ◽  
A Desideri ◽  
L Morpurgo ◽  
A Garnier-Suillerot ◽  
L Tosi
Keyword(s):  
Raman Spectra ◽  
Strong Dependence ◽  
Resonance Raman ◽  
Local Symmetry ◽  
Structural Rearrangements ◽  
Blue Copper ◽  
Copper Site ◽  
Resonance Raman Spectra ◽  
Rhus Vernicifera

Resonance-Raman spectra of Japanese-lacquer-tree (Rhus vernicifera) laccase, type-2-copper-depleted laccase and the latter form treated with H2O2 were measured in liquid and frozen solution, on excitation into the 600 nm absorption band. Significant changes in intensity and/or frequency of the bands lying in the 370-430 cm-1 region were observed on freezing, indicating local structural rearrangements taking place at the blue copper site. These findings corroborate previous suggestions based on e.p.r. measurements and redox data [Morpurgo, Calabrese, Desideri & Rotilio (1981) Biochem. J. 193, 639-642]. They show the strong dependence of the physical properties of blue copper centres on local symmetry. Some conclusions on the origin of the Raman bands are also drawn.

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