Alternate Reaction Center Acceptors: Spectral Signatures and Redox Properties of Pheoporphyrin, Zinc and Copper Bacteriochlorin Anion Radicals

1996 ◽  
pp. 369-380
Author(s):  
M. W. Renner ◽  
Y. Zhang ◽  
D. Noy ◽  
A. Scherz ◽  
K. M. Smith ◽  
...  
Keyword(s):  
Reaction Center ◽  
Redox Properties ◽  
Spectral Signatures ◽  
Anion Radicals

scholarly journals Redox properties of an H-subunit-depleted photosynthetic reaction center from Rhodopseudomonas viridis

1998 ◽  
Vol 1363 (3) ◽  
pp. 199-208 ◽  
Author(s):  
Masayuki Hara ◽  
Takeyuki Kaneko ◽  
Chikashi Nakamura ◽  
Yasuo Asada ◽  
Jun Miyake
Keyword(s):  
Reaction Center ◽  
Photosynthetic Reaction Center ◽  
Redox Properties ◽  
Rhodopseudomonas Viridis

New Metalloporphyrins with Extremely Altered Redox Properties:  Synthesis, Structure, and Facile Reduction to Air-Stable π-Anion Radicals of Zinc and Nickel β-Heptanitroporphyrins

1997 ◽  
Vol 119 (27) ◽  
pp. 6442-6443 ◽  
Author(s):  
Karine Ozette ◽  
Philippe Leduc ◽  
Magali Palacio ◽  
Jean-Francois Bartoli ◽  
Kathleen M. Barkigia ◽  
...  
Keyword(s):  
Redox Properties ◽  
Anion Radicals

Spectroscopic and redox properties of sym1 and (M)F195H: Rhodobacter capsulatus reaction center symmetry mutants which affect the initial electron donor

Biochemistry ◽  
1992 ◽  
Vol 31 (42) ◽  
pp. 10356-10362 ◽  
Author(s):  
Jonathan W. Stocker ◽  
Aileen K. W. Taguchi ◽  
Heather A. Murchison ◽  
Neal W. Woodbury ◽  
Steven G. Boxer
Keyword(s):  
Reaction Center ◽  
Electron Donor ◽  
Rhodobacter Capsulatus ◽  
Redox Properties ◽  
Initial Electron

Cytochemical Localization of Polysaccharides in Diplodia Maydis With Thiosemicarbazide : Evaluation of Three Fixatives For Pa:Tsc:Os Reaction

1976 ◽  
Vol 34 ◽  
pp. 48-49 ◽  
Author(s):  
Judith A. Murphy ◽  
Mary R. Thompson ◽  
A.J. Pappelis
Keyword(s):  
Reaction Center ◽  
Osmium Tetroxide ◽  
Periodic Acid ◽  
Cytochemical Localization ◽  
Thin Sections ◽  
Selective Reaction ◽  
Amorphous Character

In an attempt to identify polysaccharide components in thin sections of D. maydis, procedures were employed such that a PAS localization could be carried out. Three different fixatives were evaluated ie. glutaraldehyde, formaldehyde and paraformaldehyde. These were used in conjunction with periodic acid (PA), thiosemicarbazide(TSC), and osmium tetroxide(Os) to localize polysaccharides in V. maydis using a pre-embedded reaction procedure. Polysaccharide localization is based on the oxidation of vic-glycol groups by PA, and the binding of TSC as a selective reaction center for the formation of osmium black. The reaction product is sufficiently electron opaque, insoluble in lipids, not altered when tissue is embedded, and has a fine amorphous character.

Oriented Luminescent Nanostructures From Single Molecules Of Conjugated Polymers

2003 ◽  
Vol 771 ◽  
Author(s):  
Adosh Mehta ◽  
Pradeep Kumar ◽  
Jie Zheng ◽  
Robert M. Dickson ◽  
Bobby Sumpter ◽  
...  
Keyword(s):  
Conjugated Polymers ◽  
Polarization Anisotropy ◽  
Emission Pattern ◽  
Spectral Signatures ◽  
Dipole Emission ◽  
Ink Jet ◽  
Molecular Scale ◽  
Jet Printing ◽  
Photochemical Stability ◽  
Printing Techniques

AbstractDipole emission pattern imaging experiments on single chains of common conjugated polymers (solubilized poly phenylene vinylenes) isolated by ink-jet printing techniques have revealed surprising uniformity in transition moment orientation perpendicular to the support substrate. In addition to uniform orientation, these species show a number of striking differences in photochemical stability, polarization anisotropy,[1] and spectral signatures[2] with respect to similar (well-studied) molecules dispersed in dilute thin-films. Combined with molecular mechanics simulation, these results point to a structural picture of a folded macromolecule as a highly ordered cylindrical nanostructure whose long-axis (approximately collinear with the conjugation axis) is oriented, by an electrostatic interaction, perpendicular to the coverglass substrate. These results suggest a number of important applications in nanoscale photonics and molecular-scale optoelectronics.

Computational Investigation of the Asymmetry in Photosynthetic Reaction Center Models from First Principles

2020 ◽  
Author(s):  
Denis Artiukhin ◽  
Patrick Eschenbach ◽  
Johannes Neugebauer
Keyword(s):  
Spin Density ◽  
Reaction Center ◽  
Density Functional ◽  
Photosynthetic Reaction Center ◽  
Chem Phys ◽  
Molecular Structures ◽  
Error Characteristic ◽  
Molecular Systems ◽  
Density Distributions ◽  
The Asymmetry

We present a computational analysis of the asymmetry in reaction center models of photosystem I, photosystem II, and bacteria from <i>Synechococcus elongatus</i>, <i>Thermococcus vulcanus</i>, and <i>Rhodobacter sphaeroides</i>, respectively. The recently developed FDE-diab methodology [J. Chem. Phys., 148 (2018), 214104] allowed us to effectively avoid the spin-density overdelocalization error characteristic for standard Kohn–Sham Density Functional Theory and to reliably calculate spin-density distributions and electronic couplings for a number of molecular systems ranging from dimeric models in vacuum to large protein including up to about 2000 atoms. The calculated spin densities showed a good agreement with available experimental results and were used to validate reaction center models reported in the literature. We demonstrated that the applied theoretical approach is very sensitive to changes in molecular structures and relative orientation of molecules. This makes FDE-diab a valuable tool for electronic structure calculations of large photosynthetic models effectively complementing the existing experimental techniques.

Photon Emission Spectral Signatures of AlGaN/GaN HEMT for Functional and Reliability Analysis

2008 ◽  
Author(s):  
Arkadiusz Glowacki ◽  
Christian Boit ◽  
Richard Lossy ◽  
Joachim Würfl
Keyword(s):  
Reliability Analysis ◽  
Gate Voltage ◽  
Near Infrared ◽  
Photon Emission ◽  
Electrical Characterization ◽  
Spectral Signatures ◽  
Operating Modes ◽  
Gan Hemt ◽  
Spectrally Resolved ◽  
Performance Variations

Abstract Non-degraded and degraded AlGaN/GaN HEMT devices have been characterized electrically and investigated in various operating modes using integral and spectrally resolved photon emission (PE). In degraded devices the PE dependence on the gate voltage differs from the non-degraded devices. Various types of dependencies on the gate voltage have been identified when investigating local degradation sites. PE spectroscopy was performed at various bias conditions. For both devices broad spectra have been obtained in a wavelength regime from visible to near-infrared, including local performance variations. Signatures of the degradation have been determined in the electrical characterization, in integral PE distribution and in the PE spectrum.

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