Anisotropy of the emission and absorption bands of spinach chloroplasts measured by fluorescence polarization and polarized excitation spectra at low temperature

When the sub-core complex of photosystem II, D1/D2, is irradiated at 436 or 415 nm (absorption by chlorophyll and pheophytin and β-carotene) or 540 nm (absorption primarily by pheophytin), the low temperature fluorescence spectrum has two maxima, at 685 and 674 nm. This shows the existence of at least two different fluorescent forms of chlorophyll (chlorophyll a and perhaps pheophytin a). When carotene is irradiated at 485 nm (absorption primarily by β-carotene), only fluorescence at 685 nm is observed: this indicates that carotene is transferring energy to only the long-wavelength form of chlorophyll in the D1/D2 sub-core complex. The band of carotene (at 485 nm) does not appear in the fluorescence excitation spectrum, measured at 674 nm. The position of the carotene molecule relative to each of the fluorescent forms of chlorophyll was determined from the excitation spectra of each of the fluorescence bands.

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Significant blue-shift in photoluminescence excitation spectra of Nd3+:LaF3 potential laser medium at low-temperature

Optical Materials ◽

10.1016/j.optmat.2015.06.020 ◽

2015 ◽

Vol 47 ◽

pp. 462-464 ◽

Cited By ~ 8

Author(s):

Ren Arita ◽

Yuki Minami ◽

Marilou Cadatal-Raduban ◽

Minh Hong Pham ◽

Melvin John Fernandez Empizo ◽

...

Keyword(s):

Low Temperature ◽

Blue Shift ◽

Laser Medium ◽

Photoluminescence Excitation ◽

Excitation Spectra ◽

Significant Blue Shift

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Aggregation of cation-anionic and related polymethine dyes

International Journal of Photoenergy ◽

10.1155/s1110662x00000039 ◽

2000 ◽

Vol 2 (1) ◽

pp. 17-21 ◽

Cited By ~ 5

Author(s):

A. S. Tatikolov ◽

G. Ponterini ◽

Zh. A. Krasnaya

Keyword(s):

Absorption Spectra ◽

Ion Pairs ◽

Wavelength Region ◽

Polymethine Dyes ◽

Gradual Transition ◽

Solvent Mixtures ◽

Anionic Dyes ◽

Excitation Spectra ◽

Absorption Bands ◽

Fluorescence Excitation

Absorption, fluorescence, and fluorescence excitation spectra were studied for a number of cation-anionic and related anionic polymethine dyes in weakly polarand nonpolarsolvents, as well as in binary mixtures of solvents of different polarity. For some dyes, aggregation is observed in toluene or acetonitrile-toluene mixtures with low amounts of acetonitrile, which is revealed as appearance of new absorption bands and/or broadening of the initial bands of a monomeric dye. Solvent mixtures butyronitrilehexane with low butyronitrile content were found to greatly stimulate the formation of dye aggregates for most of the dyes studied. The absorption spectra of the aggregates are often blue-shifted with respect to the corresponding absorption spectra of parent monomeric dyes and/or represent broad continuums located both in the blue and red regions. For one of the cation-anionic dyes studied, which consists of3,3′-diethylthiamonomethinecyanine cation and trimethinebenzoxanine anion, fluorescent aggregates were observed; their broad fluorescence band is located in the long-wavelength region. For this dye, gradual transition from nonfluorescent aggregates to fluorescent ones and then to monomeric ion pairs and dissociated ions was observed in butyronitrile-hexane mixtures with growing butyronitrile content.

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Fourier Transform Fluorescence Spectrometry

Applied Spectroscopy ◽

10.1366/0003702884429706 ◽

1988 ◽

Vol 42 (8) ◽

pp. 1563-1566 ◽

Cited By ~ 4

Author(s):

B. Hlivko ◽

H. Hong ◽

R. R. Williams

Keyword(s):

Fourier Transform ◽

Fluorescence Polarization ◽

Fluorescence Spectra ◽

Laser Excitation ◽

Emission Spectra ◽

Laser Fluorescence ◽

Fluorescence Spectrometry ◽

Excitation Spectra ◽

Polarization Spectra ◽

Monochromatic Source

A variety of fluorescence spectra have been measured interferometrically, demonstrating the feasibility of Fourier Transform Fluorescence Spectrometry (FT-FS). Emission spectra have been measured with the use of a monochromatic source and an interferometer as the emission selector. Excitation spectra have been measured with the use of a multi-line laser. Fluorescence polarization spectra have also been recorded with the use of laser excitation. The analytical characteristics of working curves are discussed.

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Fine structure of oxygen absorption bands in Si at low temperature

Journal of Applied Physics ◽

10.1063/1.351978 ◽

1992 ◽

Vol 72 (11) ◽

pp. 5393-5396 ◽

Cited By ~ 4

Author(s):

K. Ryoo ◽

H. R. Kim ◽

J. S. Koh ◽

G. Seo ◽

J. H. Lee

Keyword(s):

Fine Structure ◽

Low Temperature ◽

Oxygen Absorption ◽

Absorption Bands

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Further resolution of chlorophyll pigments in photosystems 1 and 2 of spinach chloroplasts by low-temperature derivative spectroscopy

Biochimica et Biophysica Acta (BBA) - Bioenergetics ◽

10.1016/0005-2728(68)90016-9 ◽

1968 ◽

Vol 153 (4) ◽

pp. 889-891 ◽

Cited By ~ 18

Author(s):

W.A. Cramer ◽

W.L. Butler

Keyword(s):

Low Temperature ◽

Photosystems 1 And 2 ◽

Temperature Derivative ◽

Chlorophyll Pigments ◽

Spinach Chloroplasts ◽

Derivative Spectroscopy ◽

Temperature Derivative Spectroscopy

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Low Temperature Infrared Spectrometric Studies of Difluorodisulfane, Thiothionylfluoride and Difluorotrisulfane

Zeitschrift für Naturforschung A ◽

10.1515/zna-1975-0907 ◽

1975 ◽

Vol 30 (9) ◽

pp. 1156-1163 ◽

Cited By ~ 4

Author(s):

Karl-Peter Wanczek ◽

Claus Bliefert ◽

Rudolf Budenz

Keyword(s):

Low Temperature ◽

Solid Phase ◽

Frequency Range ◽

Absorption Bands ◽

Temperature Spectrum ◽

Decomposition Products ◽

Bond Lengths ◽

Main Decomposition ◽

Stretching Vibrations ◽

Sulfur Tetrafluoride

The low temperature IR stretching vibrations of difluorodisulfane (FSSF) and thiothionylfluoride (SSF2), in the solid phase and in a cyclohexane matrix, of the mixtures FSSF -SSF2, FSSF-OSF2 and SSF, -OSF2, and of solid difluorotrisulfane (FS3F) have been investigated. While SSF, forms no distinct oligomers, a dimer with absorption bands at 635 and 682 cm-1 has been detected in the case of FSSF. These differences between FSSF and SSF, are rationalized by the different S-F bond lengths. A structure of the FSSF dimer similar to that of the sulfur tetrafluoride dimer is proposed. The low temperature spectrum of FS3F shows 3 bands in the frequency range between 460 and 1000 cm-1: 590, 605 and 680 cm-1, due to associated molecules. FS3F decomposes on warming. The main decomposition products containing fluorine are FSSF and SSF2. Mechanisms for the rearrangement and decomposition of the three compounds studied are discussed

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Color Centers in Magnesium Doped Polycrystalline Alumina

MRS Proceedings ◽

10.1557/proc-667-g7.1 ◽

2001 ◽

Vol 667 ◽

Cited By ~ 6

Author(s):

L. R. Brock ◽

K. C. Mishra ◽

Madis Raukas ◽

Walter P. Lapatovich ◽

George C. Wei

Keyword(s):

Low Temperature ◽

Emission Band ◽

Emission Spectroscopy ◽

Color Centers ◽

Absorption Bands ◽

Fluorescence Excitation ◽

Polycrystalline Alumina ◽

Zero Phonon Line ◽

Related Defect ◽

Single Crystal Sapphire

ABSTRACTWe have investigated color centers in MgO-doped polycrystalline alumina (PCA) using absorption, excitation, and emission spectroscopy. Most of the color centers that were reported in earlier studies of the crystalline material have been observed to be present in the polycrystalline material. The absorption spectral features observed in the PCA are attributed to various color centers; however, they are not sufficiently resolved to make unique assignments. Suitable combinations of excitation and emission spectroscopy and also measurements at low temperature were therefore used to identify most of the color centers in this material.Among the numerous color centers that we have identified in PCA are variations of electron centers including F, F+, F2+, F22+ and F+-Mg ((Vo•-MgAl')x). The most prominent oxygen vacancy related defect observed at room temperature was the F+-Mg center, with absorption bands located at 217 and 249 nm, and an emission band at 303 nm. This center can be thought of as being formed by association of an F+ center with a Mg defect. The single crystal sapphire samples containing no Mg show only F+ (Vo•) centers with 230 and 257 nm absorption bands, and a 328 nm emission band.Low temperature (22 K) fluorescence excitation measurements of PCA led to emission from F22+center at 467 nm. Additionally, there is evidence that the observed 368 nm emission band could be attributed to the zero-phonon line associated with the F2+center.

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