scholarly journals Cyanine Dyes: Fine Structures in Their Absorption Spectra

2009 ◽  
Vol 8 (1) ◽  
Author(s):  
Anna Zarow ◽  
Yeung-gyo Shin
Keyword(s):  
Fine Structure ◽  
Absorption Spectra ◽  
Experimental Error ◽  
Cyanine Dyes ◽  
Electronic Coupling ◽  
Major Peak ◽  
Hydrocarbon Chains ◽  
Varying Length ◽  
Fine Structures ◽  
Intramolecular Process

Absorption spectra were studied for two series of 3 cyanine dyes with varying length of conjugated hydrocarbon chains. Fine structures in absorption spectra were analyzed to determine its concentration dependence as the concentration of dyes were changed from 10–8 M to 10–4 M. In all 6 dyes studied, ratios of minor peaks to the major peak remained constant within the experimental error. These results indicate that the origin of the absorption fine structure is due to the electronic coupling, an intramolecular process, rather than the aggregates formation, an intermolecular process.

Relationship between the Molecular Structure of Cyanine Dyes and the Vibrational Fine Structure of their Electronic Absorption Spectra

ChemPhysChem ◽  
2009 ◽  
Vol 10 (5) ◽  
pp. 835-840 ◽  
Author(s):  
Heinz Mustroph ◽  
Knut Reiner ◽  
Jürgen Mistol ◽  
Steffen Ernst ◽  
Dietmar Keil ◽  
...  
Keyword(s):  
Molecular Structure ◽  
Fine Structure ◽  
Absorption Spectra ◽  
Electronic Absorption ◽  
Electronic Absorption Spectra ◽  
Cyanine Dyes

scholarly journals On the fluorescence and channelled absorption of bismuth at high temperatures

1925 ◽  
Vol 107 (744) ◽  
pp. 760-762 ◽  
Keyword(s):  
Fine Structure ◽  
Absorption Spectra ◽  
High Temperatures ◽  
Royal Society ◽  
Visible Region ◽  
Compressed Air ◽  
Orange Yellow ◽  
Fluorescent Radiation ◽  
Absorption Chamber

In a paper recently communicated to the Royal Society, experiments dealing with the absorption spectra of several metals were described, in which it was found that bismuth vapour shows both lines and bands in absorption. The banded spectrum consists of three groups of bands, each group consisting of a number of bands degraded towards the red, the group of bands in the visible region appearing at high temperatures. In the above experiments it was hoped that by raising the temperature of the absorption chamber sufficiently high, and raising the absorption in the lines of the several bands, it might be possible to detect a fine structure in some of these bands. Accordingly, the author modified the furnace previously used so as to blow through it a larger quantity of compressed air, and succeeded finally by using coke and this furnace to obtain a temperature of about 1500°C. to 1600°C. At this temperature the vapour emitted a fluorescent radiation orange yellow in colour.

scholarly journals Fine Structure and Dynamics of the Inner Corona

1977 ◽  
Vol 43 ◽  
pp. 9-9
Author(s):  
G.E. Brueckner ◽  
J.D.F. Bartoe ◽  
M.E. VanHoosier
Keyword(s):  
Solar Wind ◽  
Fine Structure ◽  
Thermal Energy ◽  
Column Density ◽  
Line Profiles ◽  
Quiet Sun ◽  
Structure And Dynamics ◽  
Fine Structures ◽  
The Doppler Effect ◽  
Average Size

High spectral (0,05 Å) and spatial (⋍ 1000 km) resolution spectra of the Fe XII line 1349.4 Å reveal the existence of coronal fine structures in the quiet sun against the solar disk. These coronal bright elements have an average size of 2000-3000 km; their column density can be 3 x 1017 cm –2 . In the quiet sun, outward streaming velocities of 10-15 km sec –1 can be measured by means of the Doppler effect. The total kinetic and thermal energy of the outstreaming gas can be estimated to be larger than 1 x 10 5 ergs cm –2 sec –1, enough to account for the heating of the corona and the losses of the solar wind. At the outer limb (cos θ ⋍0.1) line profiles show a strong blue asymmetry, which could be caused by expanding material in a piston-driven shock, whereby the opaque, cool piston causes the asymmetry of the line profile.

X-Ray Absorption Fine Structure Study in FeTiO3

1997 ◽  
Vol 11 (16n17) ◽  
pp. 745-748 ◽  
Author(s):  
Rebekah Min-Fang Hsu ◽  
Kai-Jan Lin ◽  
Cheng Tien ◽  
Lin-Yan Jang
Keyword(s):  
Absorption Spectrum ◽  
Fine Structure ◽  
Absorption Spectra ◽  
Mixed Valence ◽  
Structure Study ◽  
X Ray ◽  
Xafs Spectroscopy ◽  
Absorption Fine ◽  
Trivalent State ◽  
X Ray Absorption

X-ray absorption fine structure XAFS spectroscopy has been used to determine the valence system for the Fe atom in ilmenite, FeTiO3 . This is the first XAFS data in FeTiO3 to our knowledge. The α- Fe2O3 data served as the standard in determining the ionization of the Fe atom in FeTiO3 . Observation of intensity and k-space are consistent. There was no evidence of mixed valence on comparing the FeTiO3 near edge X-ray absorption spectrum with α- Fe2O3 data. The absorption spectra suggest that iron is in the trivalent state in ilmenite.

scholarly journals Lamellar spacing of photosystem II membrane fragments upon dehydration studied by neutron membrane diffraction

2015 ◽  
Vol 2 (1) ◽  
Author(s):  
Jörg Pieper ◽  
Leonid Rusevich ◽  
Thomas Hauß ◽  
Gernot Renger
Keyword(s):  
Electron Transfer ◽  
Photosystem Ii ◽  
Experimental Error ◽  
Room Temperature ◽  
Lamellar Spacing ◽  
Hydration Water ◽  
Major Peak ◽  
Repeat Distance ◽  
Ps Ii ◽  
Protein Motions

AbstractThe effect of dehydration on the lamellar spacing of photosystem II (PS II) membrane fragments from spinach has been investigated using neutron membrane diffraction at room temperature. The diffraction data reveal a major peak at a scattering vector Q of 0.049 Å−1 at a relative humidity (r.h.) of 90% corresponding to a repeat distance D of about 129 Å. Upon dehydration to 44% r.h., this peak shifts to about 0.060 Å−1 corresponding to a distance of 104.7±2.5 Å. Within experimental error, the latter repeat distance remains almost the same at hydration levels below 44% r.h. indicating that most of the hydration water is removed. This result is consistent with the earlier finding that hydration-induced conformational protein motions in PS II membrane fragments are observed above 44% r.h. and correlated with the onset electron transfer in PS II (Pieper et al. 2008, Eur. Biophys. J. 37: 657–663).

scholarly journals On the influence of their state in solution on the absorption spectra of dissolved dyes

1909 ◽  
Vol 82 (554) ◽  
pp. 256-270 ◽  
Keyword(s):  
Refractive Index ◽  
Absorption Spectra ◽  
Organic Solvents ◽  
Absorption Maximum ◽  
Previous Investigation ◽  
Cyanine Dyes ◽  
Water Band ◽  
The One

In a previous investigation of the absorption spectra and sensitising properties of some iso cyanine dyes,* the influence of the solvent was examined and it was found that the absorption maximum was shifted toward the red as the refractive index of the solvent increased. This is in accordance with Kundt’s law. The absorption in water, however, differs markedly from that in organic solvents. In the latter the spectrum consists of a prominent band in the orange and a half-shade nearer the blue. In water this half-shade has become a separate band comparable in intensity with the orange. Absorption curves in alcohol and water are shown. It is convenient to term the band near the red the β-(organic) band, the one nearer the blue the α -(water) band. It appeared desirable to investigate this difference further.

Synthesis and absorption spectra of new polymethine cyanine dyes

2002 ◽  
Vol 52 (2) ◽  
pp. 129-136 ◽  
Author(s):  
Reda Mahmoud Abd El-Aal
Keyword(s):  
Absorption Spectra ◽  
Cyanine Dyes

scholarly journals The nuclear spin of iodine I— fine structure in the first spark spectrum

1935 ◽  
Vol 149 (867) ◽  
pp. 269-281 ◽  
Keyword(s):  
Fine Structure ◽  
High Resolution ◽  
Nuclear Spin ◽  
High Frequency ◽  
Complete Resolution ◽  
Electrodeless Discharge ◽  
A Value ◽  
Fabry Perot ◽  
Fine Structures ◽  
The Individual

In an earlier paper on the fine structures of the visible lines in the arc spectra of bromine and iodine an attempt was made to estimate the nuclear spin of iodine, and a tentative value of 9/2 was proposed. The iodine arc lines were excited by a high frequency electrodeless discharge in pure iodine vapour and examined with a silvered Fabry-perot interferometer. The fine structures in the arc lines are small, and as the patterns are highly complex and the individual components not very sharp, interpretation was difficult. It was concluded with certainty that the nuclear spin was at least equal to 5/2, but one line in particular suggested a value of 9/2. This was indefinite, and in view of the uncertainty a thorough examination of both the arc and spark spectra of iodine has been undertaken. A preliminary notice has already appeared. The first spark spectrum can be more easily studied than the arc spectrum, since the structure are on a very much bigger scale and more complete resolution can be attained. The present work is concerned with the spark lines excited in a hollow cathode discharge. Fine structures in iodine spark lines were first recorded long ago by Wood and Kimura who excited the lines in a Geissler tube and examined them with a transmission echelon. Murakawa attempted to analyse the fine structure data, but as the source and instrument employed by Wood and Kimura were not able to give the high resolution attained here, the deductions made from these data, although generally correct, are uncertain and require further examination; for many of the line structures are much more complex than as reported by these earlier observers.

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