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.

The resonance Raman spectra and excitation profiles of some 4-sulfamylazobenzenes

1977 ◽  
Vol 55 (9) ◽  
pp. 1444-1453 ◽  
Author(s):  
Kamal Kumar ◽  
P. R. Carey
Keyword(s):  
Raman Spectrum ◽  
Raman Spectra ◽  
Resonance Raman ◽  
Valence Bond ◽  
Wavelength Dependence ◽  
Accurate Estimation ◽  
Intensity Changes ◽  
Stretching Vibration ◽  
Resonance Raman Spectra ◽  
Frequency Changes

The resonance Raman spectra of three pharmacologically important sulfonamides, 4-sulfamyl-4′-dimethylaminoazobenzene (1), 4-sulfamyl-4′-hydroxyazobenzene (2), and 4-sulfamyl-4′-aminoazobenzene (3), are compared with those of analogues lacking the sulfonamide group. The —SO2NH2 moiety does not directly contribute intense or moderately intense bands to the resonance Raman spectra of 1, 2, and 3. However, —SO2NH2 ionization is reflected by frequency changes in a band near 1140 cm−1 and intensity changes in the 1420 cm−1 region. The normal Raman spectrum of 2 confirms that the intensity changes reflect —SO2NH2 ionization rather than unrelated changes in vibronic coupling. The effect of —OH ionization on the resonance Raman spectrum of 2 emphasizes that caution must be exercised when relating spectral perturbations to changes in contributions from valence bond type structures. Resonance Raman excitation profiles for the 1138, 1387, and 1416 cm−1 bands of 2 show that these bands gain intensity by coupling with the electronic transitions in the 240 to 450 nm region and that, more than 1000 cm−1 to the red of λmax, the wavelength dependence can be closely reproduced by the FB type terms of Albrecht and Hutley. The excitation profile for each band shows evidence for structure in the 470 nm region, although lack of sufficient excitation wavelengths prevents accurate estimation of the spacing. Under conditions of rigorous resonance the intense Raman lines all occur in the 1400 cm−1 region, i.e. they are 'bunched' in the region known to contain the —N=N— stretching vibration.

Selective calculation of high-intensity vibrations in molecular resonance Raman spectra

2008 ◽  
Vol 129 (20) ◽  
pp. 204103 ◽  
Author(s):  
Karin Kiewisch ◽  
Johannes Neugebauer ◽  
Markus Reiher
Keyword(s):  
Raman Spectra ◽  
High Intensity ◽  
Resonance Raman ◽  
Resonance Raman Spectra ◽  
Molecular Resonance

Electronic Raman Spectra of a Low-Spin FeIII Porphyrin and Reexamination of the Vibrational Spectra of K3[Fe(CN)6] and [Fe(C5H5)2]BF4

1995 ◽  
Vol 50 (9) ◽  
pp. 881-887 ◽  
Author(s):  
Svend Sievertsen ◽  
Lutz Galich ◽  
Heiner Homborg
Keyword(s):  
Phase Transition ◽  
Raman Spectrum ◽  
Raman Spectra ◽  
Ground State ◽  
Raman Effect ◽  
Resonance Raman ◽  
Spin Orbit ◽  
Octahedral Symmetry ◽  
Molecular Electronic ◽  
Resonance Raman Spectra

The resonance Raman spectra of (nBu4N)[Fe(CN)2TPP] ((nBu4: tetra(n-butyl)ammonium; TPP: m-tetraphenylporphyrin), K3 [Fe(CN)6] and [Fe(C5H5)2]BF4 have been investigated. A molecular electronic Raman (ER) effect at 545 cm-1 is observed for (nBu4N)[Fe(CN)2TPP]. The transition occurs between lower “Γ7” and upper “Γ8” level of the spin-orbit split ground state assuming pseudo-octahedral symmetry. In contrast to earlier studies no ER effect is detected for K3[Fe(CN)6] and [Fe(C5H5)2]BF4. For Raman shifts < 800 cm-1 only one strong Raman line is observed for [Fe(C5H5)2]BF4 at 311 cm-1, assigned to the iron ring stretch designated by ν4 (a1g in D5d). Due to a phase transition of K3[Fe(CN)6], two additional strong vibrational lines at 329 and 352 cm-1 appear in the Raman spectrum taken at 10 K. Their intensities show A "term" behaviour of the resonance Raman effect with overtones and combinations for both lines. These are components of the vibronic combinations with the ν6, ν7, and ν8 modes (t1u in Oh) in the IR spectra, too.

Resonance Raman spectrum of a deuterated crystal violet: [p(CH3)2N•C6D4]3C+Cl−

1981 ◽  
Vol 59 (6) ◽  
pp. 964-967 ◽  
Author(s):  
S. Sunder ◽  
H. J. Bernstein
Keyword(s):  
Aqueous Solution ◽  
Raman Spectrum ◽  
Raman Spectra ◽  
Crystal Violet ◽  
Resonance Raman ◽  
Resonance Raman Spectrum ◽  
Dilute Aqueous Solution ◽  
Resonance Raman Spectra

Resonance Raman spectra have been obtained for a deuterated crystal violet [p(CH3)2N•C6D4]3C+Cl−, as a dilute aqueous solution. The assignment of some of the strong features seen in the spectra of crystal violet and deuterated crystal violet is discussed.

The Resonance Raman Spectrum of the Metalloprotein Ovotransferrin

1974 ◽  
Vol 52 (4) ◽  
pp. 273-280 ◽  
Author(s):  
Paul R. Carey ◽  
N. Martin Young
Keyword(s):  
Raman Spectrum ◽  
Metal Binding ◽  
Resonance Raman Spectroscopy ◽  
Resonance Raman ◽  
Resonance Raman Spectrum ◽  
Visible Absorption ◽  
Direct Binding ◽  
Resonance Raman Spectra ◽  
Related Compounds ◽  
Infrared Data

Using ovotransferrin it is shown that amino-acid side chains forming the metal binding site in coloured metalloproteins can be identified and monitored by resonance Raman spectroscopy. All major features above 800 cm−1 in the resonance Raman spectrum of iron–bicarbonate ovotransferrin could be assigned to histidine or tyrosine vibrational modes, by comparison with Raman and infrared data for these amino acids and related compounds. Comparison of the features due to ring modes of imidazole ligated to Fe3+ in ovotransferrin with those of aqueous histidine at pH 8.0 suggests that rearrangement of the ring π electrons takes place upon ligation. Although iron–bicarbonate and iron–oxalate ovotransferrin have similar visible absorption spectra, differences in their resonance Raman spectra are clearly distinguishable, but no evidence was found for the direct binding of bicarbonate or oxalate to the iron. Differences between the geometries of the two sites at which iron is bound in iron–bicarbonate ovotransferrin appeared to be small compared with the perturbation caused to these sites by replacing bicarbonate with oxalate.

scholarly journals Resonanz-Raman-Spektrum von Tetrabutylammoniiimoktaiododirhenat(III), [(n-C4H9)4N]2[Re2I8] Resonance Raman Spectrum of Tetrabutylammoniumoctaiododirhenate(III), [(n-C4H9)4N]2[Re2l8]

1979 ◽  
Vol 34 (9) ◽  
pp. 1240-1242 ◽  
Author(s):  
W. Preetz ◽  
G. Peters ◽  
L. Rudzik
Keyword(s):  
Raman Spectrum ◽  
Raman Spectra ◽  
Resonance Raman ◽  
Spectroscopic Constants ◽  
Resonance Raman Spectrum ◽  
Electronic Band ◽  
Band Maximum ◽  
Resonance Raman Spectra

Abstract Irradiation of [(n-C4H9)4N]2[Re2l8] at 80 K with exciting laser lines, which approximately coincide with the electronic band maximum at 520 nm, exhibits resonance Raman spectra. Overtone progressions of ν1(Re-Re) and ν2(Re-I), both A1g, and many combination tones are observed. The spectroscopic constants are calculated to be ω1 =258,5 cm -1 , x11 = - 0,42 cm-1 ; ω2 -153,0 cm-1 , x12 = - 0,32 cm-1.

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