Quantitative absorption spectra of quantum wires measured by analysis of attenuated internal emissions

2012 ◽  
Vol 100 (11) ◽  
pp. 112101 ◽  
Author(s):  
Masahiro Yoshita ◽  
Takayuki Okada ◽  
Hidefumi Akiyama ◽  
Makoto Okano ◽  
Toshiyuki Ihara ◽  
...  
Keyword(s):  
Absorption Spectra ◽  
Quantum Wires ◽  
Quantitative Absorption

scholarly journals Chromophore Content and Molar Absorptivity of Phytochrome in the Pr Form

1981 ◽  
Vol 36 (5-6) ◽  
pp. 431-439 ◽  
Author(s):  
Thomas Brandlmeier ◽  
Hugo Scheer ◽  
Wolfhart Rüdiger
Keyword(s):  
Absorption Spectra ◽  
Spirulina Platensis ◽  
Molar Absorptivity ◽  
Suitable Model ◽  
Model Compounds ◽  
Quantitative Absorption

Abstract Quantitative absorption spectra in the visible and UV region were recorded for denaturated phytochrome (P r) and phytochromobilin peptides in comparison with native Pr. The method was tested with C-phycocyanin from Spirulina platensis. Based on known molar absorptivities for denaturated phycocyanin and suitable model compounds, and on the ratio A620native/A655-665degraded = 2.9, ^native was determined to be 102000 m-1 cm-1 for one phycocyanobilin chromophore in native phycocyanin. Likewise, Native was calculated to be 19000 M-1 cm-1. The corresponding ratios for Pr were Anative/Adenatured = 3.4 and Anative/Adegraded = 3.7, this yielded ε665native = 109000 to 118000 and ε380native = 36000 M-1 cm-1 for phytochromobilin in native P r. This value corresponds to one phytochromobilin per small phytochrome (60000 D) if data from the literature are corrected for the content of colorless proteins. The latter has been asessed from (i) the purity index (A280/A665) and (ii) the contribution of the phytochromobilin chromophore at 280 nm as derived from model compounds.

Quantitative Messung der Singulett- und Triplett-Absorptions-Spektren von Phäophytin a und b / Pheophytin-a and Pheophytin-b; Quantitative Absorption Spectra of the Singuletand Triplet-State

1970 ◽  
Vol 25 (10) ◽  
pp. 1137-1143 ◽  
Author(s):  
Valentin Zanker ◽  
Ernst Rudolph ◽  
Gerhart Prell
Keyword(s):  
Absorption Spectra ◽  
Relaxation Times ◽  
Quantum Yields ◽  
Polar Solvents ◽  
Pheophytin A ◽  
First Order ◽  
First Order Kinetics ◽  
Quantitative Absorption ◽  
Electron Transfers ◽  
Triplet Formation

Quantitative singlet absorption spectra dependent on solvent, temperature, and concentration are shown. The bands observed in the visible and UV region are assigned to 3 π → π*-electron transfers.Measurements at different acidities showed that the pheophytin molecule can be present in 3 prototropic forms; as a base, a mono- or a divalent cation.In polar solvents of concentrations >10-4 M dimerization occurred. Larger clusters were formed in non-polar solvents at concentrations <10-4 Μ and at temperatures below ca. 200 °K.The quantitative triplet (T) -absorption spectra for pheophytin a and b are also reported: the longest wavelength T-T-band is expected in the region 5000-8000 cm-1. The relaxation times and quantum yields of triplet formation are given; simple first order kinetics were found to fit the decay curves.

Quantitative Absorption spectra via photoacoustic phase angle spectroscopy (ΦAS)

1978 ◽  
Vol 60 (1) ◽  
pp. 112-116 ◽  
Author(s):  
Joseph C. Roark ◽  
Richard A. Palmer ◽  
James S. Hutchison
Keyword(s):  
Absorption Spectra ◽  
Phase Angle ◽  
Quantitative Absorption
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