Antivitamins B12 in a Microdrop: The Excited-State Structure of a Precious Sample Using Transient Polarized X-ray Absorption Near-Edge Structure

2019 ◽  
Vol 10 (18) ◽  
pp. 5484-5489 ◽  
Author(s):  
Nicholas A. Miller ◽  
Lindsay B. Michocki ◽  
Roberto Alonso-Mori ◽  
Alexander Britz ◽  
Aniruddha Deb ◽  
...  
Keyword(s):  
Excited State ◽  
State Structure ◽  
Edge Structure ◽  
X Ray ◽  
X Ray Absorption

scholarly journals Ballistic excited state dynamics revealed by polarized fs-XANES

2019 ◽  
Vol 205 ◽  
pp. 05014 ◽  
Author(s):  
Roseanne J. Sension ◽  
Nicholas A. Miller ◽  
Aniruddha Deb ◽  
Roberto Alonso-Mori ◽  
James M. Glownia ◽  
...  
Keyword(s):  
Excited State ◽  
Time Resolved ◽  
Edge Structure ◽  
X Ray ◽  
Excited State Dynamics ◽  
X Ray Absorption

Polarized time-resolved X-ray absorption near edge structure (XANES) is used to characterize the sequential ballistic excited state dynamics of two B12 vitamers: cyanocobalamin and adenosylcobalamin. Excitation at 550 nm and 365 nm is used to resolve axial and equatorial contributions to the excited state dynamics.

scholarly journals Ballistic ΔS=2 Intersystem Crossing in a Cobalt Cubane Following Ligand-Field Excitation Probed by Extreme Ultraviolet Spectroscopy

2021 ◽  
Author(s):  
Yusef Shari'ati ◽  
Josh Vura-Weis
Keyword(s):  
Excited State ◽  
Extreme Ultraviolet ◽  
Xanes Spectroscopy ◽  
Ligand Field ◽  
Ultraviolet Spectroscopy ◽  
Intersystem Crossing ◽  
Edge Structure ◽  
X Ray ◽  
Field Excitation ◽  
X Ray Absorption

Femtosecond M2,3-edge X-ray absorption near-edge structure (XANES) spectroscopy is used to probe the excited-state dynamics of the cobalt cubane [CoIII4O4](OAc)4(py)4 (OAc = acetate, py = pyridine), a model for water...

scholarly journals Ballistic ΔS=2 Intersystem Crossing in a Cobalt Cubane Following Ligand-Field Excitation Probed by Extreme Ultraviolet Spectroscopy

2021 ◽  
Author(s):  
Yusef Shari'ati ◽  
Josh Vura-Weis
Keyword(s):  
Excited State ◽  
Water Oxidation ◽  
Extreme Ultraviolet ◽  
Ligand Field ◽  
Ultraviolet Spectroscopy ◽  
Intersystem Crossing ◽  
Edge Structure ◽  
X Ray ◽  
Field Excitation ◽  
X Ray Absorption

Femtosecond M2,3-edge X-ray absorption near-edge structure (XANES) spectroscopy is used to probe the excited-state dynamics of the cobalt cubane [CoIII4O4](OAc)4(py)4 (OAc = acetate, py = pyridine), a model for water oxidation catalysts. After ligand-field excitation, intersystem crossing to a metal-centered quintet occurs in 38 fs. 30% of the hot quintet undergoes ballistic back-ISC directly to the singlet ground stat, with the remainder relaxing to a long-lived triplet.

scholarly journals Probing spin–vibronic dynamics using femtosecond X-ray spectroscopy

2016 ◽  
Vol 194 ◽  
pp. 731-746 ◽  
Author(s):  
T. J. Penfold ◽  
M. Pápai ◽  
T. Rozgonyi ◽  
K. B. Møller ◽  
G. Vankó
Keyword(s):  
Excited State ◽  
Degrees Of Freedom ◽  
Free Electrons ◽  
Edge Structure ◽  
Pump Probe ◽  
X Ray ◽  
Wavepacket Dynamics ◽  
Methyl Imidazole ◽  
Probe Spectroscopy ◽  
X Ray Absorption

Ultrafast pump-probe spectroscopy within the X-ray regime is now possible owing to the development of X-ray Free Electrons Lasers (X-FELs) and is opening new opportunities for the direct probing of femtosecond evolution of the nuclei, the electronic and spin degrees of freedom. In this contribution we use wavepacket dynamics of the photoexcited decay of a new Fe(ii) complex, [Fe(bmip)2]2+ (bmip = 2,6-bis(3-methyl-imidazole-1-ylidine)pyridine), to simulate the experimental observables associated with femtosecond Fe K-edge X-ray Absorption Near-Edge Structure (XANES) and X-ray emission (XES) spectroscopy. We show how the evolution of the nuclear wavepacket is translated into the spectroscopic signal and the sensitivity of these approaches for following excited state dynamics.

scholarly journals Ultrafast X-ray Absorption Near Edge Structure Reveals Ballistic Excited State Structural Dynamics

2018 ◽  
Vol 122 (22) ◽  
pp. 4963-4971 ◽  
Author(s):  
Nicholas A. Miller ◽  
Aniruddha Deb ◽  
Roberto Alonso-Mori ◽  
James M. Glownia ◽  
Laura M. Kiefer ◽  
...  
Keyword(s):  
Excited State ◽  
Structural Dynamics ◽  
Edge Structure ◽  
X Ray ◽  
X Ray Absorption

Chemical and orientational imaging of polymeric samples

1994 ◽  
Vol 52 ◽  
pp. 68-69
Author(s):  
H. Ade ◽  
B. Hsiao ◽  
G. Mitchell ◽  
E. Rightor ◽  
A. P. Smith ◽  
...  
Keyword(s):  
Ethylene Terephthalate ◽  
National Laboratory ◽  
Brookhaven National Laboratory ◽  
Carbonyl Groups ◽  
Aromatic Rings ◽  
Edge Structure ◽  
X Ray ◽  
Scanning Transmission ◽  
Polymeric Samples ◽  
X Ray Absorption

We have used the Scanning Transmission X-ray Microscope at beamline X1A (X1-STXM) at Brookhaven National Laboratory (BNL) to acquire high resolution, chemical and orientation sensitive images of polymeric samples as well as point spectra from 0.1 μm areas. This sensitivity is achieved by exploiting the X-ray Absorption Near Edge Structure (XANES) of the carbon K edge. One of the most illustrative example of the chemical sensitivity achievable is provided by images of a polycarbonate/pol(ethylene terephthalate) (70/30 PC/PET) blend. Contrast reversal at high overall contrast is observed between images acquired at 285.36 and 285.69 eV (Fig. 1). Contrast in these images is achieved by exploring subtle differences between resonances associated with the π bonds (sp hybridization) of the aromatic groups of each polymer. PET has a split peak associated with these aromatic groups, due to the proximity of its carbonyl groups to its aromatic rings, whereas PC has only a single peak.

Full-Field Calcium K-Edge X-ray Absorption Near-Edge Structure Spectroscopy on Cortical Bone at the Micron-Scale: Polarization Effects Reveal Mineral Orientation

2016 ◽  
Vol 88 (7) ◽  
pp. 3826-3835 ◽  
Author(s):  
Bernhard Hesse ◽  
Murielle Salome ◽  
Hiram Castillo-Michel ◽  
Marine Cotte ◽  
Barbara Fayard ◽  
...  
Keyword(s):  
Cortical Bone ◽  
Edge Structure ◽  
Full Field ◽  
Polarization Effects ◽  
X Ray ◽  
X Ray Absorption
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