Spectroelectrochemical Study of some μ3-Oxo-μ-acetato Trinuclear Rhodium(III) and Iridium(III) Complexes

1995 ◽  
Vol 50 (4) ◽  
pp. 551-557 ◽  
Author(s):  
Kenta Takahashi ◽  
Keisuke Umakoshi ◽  
Akihiro Kikuchi ◽  
Yoichi Sasaki ◽  
Masato Tominaga ◽  
...  
Keyword(s):  
Absorption Spectrum ◽  
Electronic Absorption Spectrum ◽  
Absorption Spectra ◽  
Electronic Absorption ◽  
Electronic Absorption Spectra ◽  
Visible Region ◽  
Absorption Bands ◽  
Visible Absorption ◽  
The One ◽  
Species Being

New trinuclear rhodium(III) complexes, [Rh3(μ3-O)(μ-CH3COO)6(L)3]+ (L = imidazole (Him), 1-methylimidazole (Meim), and 4-methylpyridine (Mepy)) have been prepared. The Him, Meim, and Mepy complexes show reversible one-electron oxidation waves at E1/2 = +1.12, +1.12, and +1.28 V vs Ag/AgCl, respectively, in acetonitrile. Electronic absorption spectra of the one electron oxidized species of these complexes and [Rh3(μ3-O)(μ-CH3COO)6(py)3]+ (py = pyridine) (E1/2 = +1.32 V ) were obtained by spectroelectrochemical techniques. While the Rh3(III,III,III) states show no strong visible absorption, the Rh3(III,III,IV ) species give a band at ca. 700 nm (ε = 3390-5540 mol dm-3 cm-1). [Ir3(μ3-O)(μ-CH3COO)6(py)3]+ with no strong absorption in the visible region, shows two reversible one-electron oxidation waves at +0.68 and +1.86 V in acetonitrile. The electronic absorption spectrum of the one-electron oxidized species (Ir3(III,III,IV )) also shows some absorption bands (688 nm (ε, 5119), 1093 (2325) and 1400 (ca. 1800)). It is suggested that the oxidation removes an electron from the fully occupied anti-bonding orbital based on metal-dπ-μ3-O-pπ interactions, the absorption bands of the (III,III,IV ) species being assigned to transitions to the anti-bonding orbital.

The Electronic Absorption Spectrum of Thioformaldehyde

1975 ◽  
Vol 53 (19) ◽  
pp. 1927-1928 ◽  
Author(s):  
R. H. Judge ◽  
G. W. King
Keyword(s):  
Absorption Spectrum ◽  
Electronic Absorption Spectrum ◽  
Absorption Spectra ◽  
Electronic Absorption ◽  
Electronic Absorption Spectra ◽  
Preliminary Results

The electronic absorption spectra of thioformaldehyde and thioformaldehyde-d2 have been obtained. Preliminary results of vibrational and rotational analyses are given.

Infrared and Electronic Absorption Spectra of Isoquinoline

1970 ◽  
Vol 24 (3) ◽  
pp. 344-347 ◽  
Author(s):  
R. Ammini Amma ◽  
S. N. Thakur ◽  
K. P. R. Nair
Keyword(s):  
Absorption Spectrum ◽  
Electronic Absorption Spectrum ◽  
Absorption Spectra ◽  
Vapor Phase ◽  
Electronic Absorption ◽  
Ir Spectrum ◽  
Electronic Absorption Spectra ◽  
Vibrational Analysis

The ir spectrum of isoquinoline has been investigated in the region 700–4000 cm−1. The observed frequencies have been correlated to the Raman frequencies and assigned to different modes of vibrations. The electronic absorption spectrum of the molecule has also been recorded in vapor phase in the region 2900–3200 Å. The system has been assigned to n–π* transition with the electronic origin at 31 984 cm−1. A vibrational analysis for the system is proposed.

PYRIDINE N-OXIDE COMPLEXES OF ZIRCONYL, THORIUM, AND URANYL PERCHLORATES

1964 ◽  
Vol 42 (4) ◽  
pp. 856-860 ◽  
Author(s):  
P. Rama Murthy ◽  
C. C. Patel
Keyword(s):  
Absorption Spectra ◽  
Electronic Absorption ◽  
Electronic Absorption Spectra ◽  
Visible Region ◽  
Lone Pair ◽  
Vibrational Structure ◽  
Uranyl Complexes ◽  
Bond Character

Pyridine N-oxide complexes having the composition ZrO(Py•O)6(ClO4)2, Th(Py•O)8(ClO4)4, and UO2(Py•O)5(ClO4)2 have been prepared. The infrared and electronic absorption spectra show that the bonding between the metal and pyridine N-oxide in the complexes has occurred by donation of the lone pair of p-electrons on oxygen to the metal, and that the π-bond character of NO group increases in the complexes as uranyl < thorium < zirconyl. The decrease in the vibrational structure of the UO22+ spectrum in the visible region indicates strong coordination of pyridine N-oxide to the uranyl group. The decomposition temperatures of zirconyl, thorium, and uranyl complexes are 307, 350, and 319 °C respectively.

The electronic spectra of phenyl radicals

1965 ◽  
Vol 287 (1411) ◽  
pp. 457-470 ◽  
Keyword(s):  
Absorption Spectrum ◽  
Electronic Absorption Spectrum ◽  
Electronic Absorption ◽  
Ground State ◽  
Electronic Spectra ◽  
Flash Photolysis ◽  
Visible Region ◽  
Electronic Configuration ◽  
Vibrational Structure ◽  
Fundamental Frequencies

An electronic absorption spectrum, attributed to phenyl, has been observed in the visible region with origin at 18 908 cm -1 after flash photolysis of benzene and halogenobenzenes. Similar spectra of fluoro, chloro and bromo phenyl are observed after flash photolysis of disubstituted benzenes. The vibrational structure of the phenyl spectrum has been analysed in terms of two fundamental frequencies at 571 and 896 cm -1 which correspond to the e 2 g and a 1 g frequencies of the B 2 u state of benzene. The ground state of phenyl has a π 6 n electronic configuration and the observed transition is interpreted as 2 A 1 → 2 B 1 resulting from a π → n excitation.

scholarly journals Detection by low-temperature magnetic circular-dichroism spectroscopy of optical absorption bands due to molybdenum (V) in the form of xanthine oxidase giving the Desulpho Inhibited e.p.r. signal

1986 ◽  
Vol 233 (1) ◽  
pp. 107-110 ◽  
Author(s):  
J Peterson ◽  
C Godfrey ◽  
A J Thomson ◽  
G N George ◽  
R C Bray
Keyword(s):  
Circular Dichroism ◽  
Low Temperature ◽  
Xanthine Oxidase ◽  
Absorption Spectra ◽  
Magnetic Circular Dichroism ◽  
Electronic Absorption Spectra ◽  
Visible Region ◽  
Absorption Bands ◽  
Magnetic Circular Dichroism Spectroscopy ◽  
Circular Dichroïsm

The magnetic circular-dichroism (m.c.d.) spectra in the temperature range 1.5-100 K and the electronic absorption spectra at 4.2 and 295 K were measured for a number of desulpho xanthine oxidase derivatives. There were no significant differences between the absorption spectra that could be attributed to molybdenum. However, the visible-region m.c.d. spectrum of the ethanediol-treated metalloprotein (which gives rise to the Desulpho Inhibited e.p.r. signal) contained features assignable to Mo(V) absorption bands. This is the first report of the detection of optical bands of Mo(V) in an enzyme in the presence of other chromophoric centres.

Complexes moléculaires d'hétérocycles soufrés et oxygénés. Étude spectrophotométrique de bandes de transfert de charge multiples

1982 ◽  
Vol 60 (7) ◽  
pp. 862-871 ◽  
Author(s):  
Jean-Paul Canselier ◽  
Serge Domenech ◽  
Štefan Stankovsky ◽  
Sabine Gautier
Keyword(s):  
Charge Transfer ◽  
Absorption Spectra ◽  
Electronic Absorption ◽  
Electronic Absorption Spectra ◽  
Molecular Complexes ◽  
The Other ◽  
Ionization Potentials ◽  
Nonpolar Solvents ◽  
Other Hand ◽  
The One

As with benzenoid donors, the electronic absorption spectra of the molecular complexes of simple or condensed sulfur or oxygen-containing five-membered heterocycles with TCNE (or DDQ) often show two charge-transfer bands. In many cases, the knowledge of the actual frequencies requires a technique of resolution. The results so obtained are correlated with the ionization potentials of donors on the one hand, and the refractivity of nonpolar solvents on the other hand.

Intracavity Electronic Absorption Spectra of MoO and WO Molecules in the Visible Region

1997 ◽  
Vol 30 (6) ◽  
pp. 1057-1066 ◽  
Author(s):  
Yu. Ya. Kuzyakov ◽  
E. N. Moskvitina ◽  
E. N. Filippova
Keyword(s):  
Absorption Spectra ◽  
Electronic Absorption ◽  
Electronic Absorption Spectra ◽  
Visible Region

scholarly journals Electronic spectra of carbon chains of relevance to astrophysics

1997 ◽  
Vol 178 ◽  
pp. 287-294
Author(s):  
John P. Maier
Keyword(s):  
Absorption Spectra ◽  
Electronic Absorption ◽  
Electronic Spectra ◽  
Homologous Series ◽  
Electronic Absorption Spectra ◽  
Absorption Bands ◽  
Carbon Chains ◽  
Diffuse Interstellar Bands ◽  
Spectroscopic Characteristics

The electronic absorption spectra of a variety of carbon chains have been identified in the laboratory. The measurements were carried out in 5 K neon matrices on mass-selected species. On the basis of the trends evident in the homologous series, it can be predicted in which region absorption bands of the carbon chains are to be expected for the not yet measured longer and isoelectronic species. The spectroscopic characteristics, photostability and structural considerations point out which and what size carbon chains could be the diffuse interstellar bands absorbers.

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