Energy transfer within pc trimers of mastigocladus laminosus studied by picosecond time-resolved transient absorption spectroscopy

1988 ◽  
Vol 43 (1-2) ◽  
pp. 55-62 ◽  
Author(s):  
S. Schneider ◽  
P. Geiselhart ◽  
S. Siebzehnrübl ◽  
R. Fischer ◽  
H. Scheer
Keyword(s):  
Energy Transfer ◽  
Least Squares ◽  
Absorption Spectroscopy ◽  
Transient Absorption ◽  
Transient Absorption Spectroscopy ◽  
Transfer Time ◽  
Acceptor State ◽  
Time Resolved ◽  
Picosecond Pulses ◽  
Exponential Fit

The transient absorption recovery induced in phycocyanin trimers by picosecond pulses of variable wavelength (570-620 nm) has been recorded and analyzed by applying a least-squares multi-exponential fit procedure. The results suggest that in native PC trimers the chromophores exhibit a microheterogeneity with the effect that the derived apparent lifetimes are functions of excitation and probing wavelength. It is suggested that, due to strong excitonic coupling between a-84 and β-84 chromophores, the lifetime of the terminal acceptor state is reduced to about 900 ps; the apparent energy transfer time from chromophore β-155 to a-84 and β-84 chromophores varies between 20-50 ps depending on the actual chromophore-protein arrangement (microheterogeneity)

Decoupling the artificial special pair to slow down the rate of singlet energy transfer

2012 ◽  
Vol 16 (05n06) ◽  
pp. 685-694 ◽  
Author(s):  
Pierre D. Harvey ◽  
Adam Langlois ◽  
Mikhail Filatov ◽  
Daniel Fortin ◽  
Kei Ohkubo ◽  
...  
Keyword(s):  
Energy Transfer ◽  
Absorption Spectroscopy ◽  
Density Functional ◽  
Transient Absorption ◽  
Geometry Optimization ◽  
Transient Absorption Spectroscopy ◽  
Free Base ◽  
Functional Theory ◽  
Time Resolved ◽  
Slow Rise

Trimer 2, composed of a cofacial heterobismacrocycle, octamethyl-porphyrin zinc(II) and bisarylporphyrin zinc(II) held by an anthracenyl spacer, and a flanking acceptor, bisarylporphyrin free-base ( Ar = -3,5-(t Bu )2 C 6 H 3), has been studied by means of absorption spectroscopy, "steady state and time-resolved fluorescence" and fs transient absorption spectroscopy, and density functional theory (DFT) in order to assess the effect of decoupling the chromophores' low energy MOs on the rate of the singlet, S1, energy transfer, k ET , compared to a recently reported work on a heavily coupled trimeric system, Trimer 1, [biphenylenebis(n-nonyl)porphyrin zinc(II)]-bisarylporphyrin free-base ( Ar = -3,5-(t Bu )2 C 6 H 3). The position of the 0–0 peaks of the absorption and fluorescence spectra of Trimer 2 indicates that these porphyrin units are respectively energy donor 1, donor 2, and acceptor. The DFT computations confirm that the MOs of the cofacial donor 1-donor 2 dyad are decoupled, but significant MO coupling between donor 2 and acceptor 1 is still present despite the strong dihedral angle between their respective average planes (77.5°: geometry optimization by DFT). The fs transient absorption spectra exhibit a clear S1–Sn fingerprint of the bisarylporphyrin zinc(II) chromophore and the kinetic trace exhibits a slow rise time of 87 ps, due to a S1 donor 1 → donor 2 ET. The transient species donor 2 and acceptor decay respectively in the short (~1.5) ns and 6 ns time scale.

Ultrafast Heme Dynamics in Ferrous versus Ferric CytochromecStudied by Time-Resolved Resonance Raman and Transient Absorption Spectroscopy

2006 ◽  
Vol 110 (25) ◽  
pp. 12766-12781 ◽  
Author(s):  
Michel Negrerie ◽  
Simona Cianetti ◽  
Marten H. Vos ◽  
Jean-Louis Martin ◽  
Sergei G. Kruglik
Keyword(s):  
Absorption Spectroscopy ◽  
Transient Absorption ◽  
Resonance Raman ◽  
Transient Absorption Spectroscopy ◽  
Time Resolved

scholarly journals Towards understanding non-equivalence of α and β subunits within human hemoglobin in conformational relaxation and molecular oxygen rebinding

2021 ◽  
Author(s):  
Sergei V. Lepeshkevich ◽  
Igor V. Sazanovich ◽  
Marina V. Parkhats ◽  
Syargey N. Gilevich ◽  
Boris M. Dzhagarov
Keyword(s):  
Molecular Oxygen ◽  
Absorption Spectroscopy ◽  
Transient Absorption ◽  
Transient Absorption Spectroscopy ◽  
Human Hemoglobin ◽  
Time Resolved ◽  
Conformational Relaxation ◽  
Α And Β Subunits ◽  
Millisecond Laser

Picosecond to millisecond laser time-resolved transient absorption spectroscopy was used to study molecular oxygen (O2) rebinding and conformational relaxation following O2 photodissociation in the α and β subunits within human...

scholarly journals Tracking dissociation dynamics of strong-field ionized 1,2-dibromoethane with femtosecond XUV transient absorption spectroscopy

2016 ◽  
Vol 18 (21) ◽  
pp. 14644-14653 ◽  
Author(s):  
Adam S. Chatterley ◽  
Florian Lackner ◽  
Daniel M. Neumark ◽  
Stephen R. Leone ◽  
Oliver Gessner
Keyword(s):  
Absorption Spectroscopy ◽  
Near Infrared ◽  
Transient Absorption ◽  
Extreme Ultraviolet ◽  
Strong Field ◽  
Transient Absorption Spectroscopy ◽  
Time Resolved ◽  
Strong Field Ionization ◽  
Dissociation Dynamics ◽  
Ultraviolet Absorption Spectroscopy

Using femtosecond time-resolved extreme ultraviolet absorption spectroscopy, the dissociation dynamics of the haloalkane 1,2-dibromoethane (DBE) have been explored following strong field ionization by femtosecond near infrared pulses at intensities between 7.5 × 1013 and 2.2 × 1014 W cm−2.

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