Linear Dichroism Spectroscopy of Retinal with Picosecond Time Resolution

1985 ◽  
Vol 40 (11-12) ◽  
pp. 880-885
Author(s):  
M. E. Lippitsch ◽  
M. Riegler ◽  
F. R. Aussenegg ◽  
N. Friedman ◽  
M. Sheves ◽  
...  
Keyword(s):  
Transient Absorption ◽  
Molecular Geometry ◽  
Linear Dichroism ◽  
Triplet States ◽  
Polyethylene Films ◽  
Transient Absorption Spectra ◽  
Time Regime ◽  
Singlet And Triplet States ◽  
First Time ◽  
Time Linear

Abstract For the first time linear dichroism spectroscopy has been extended to the picosecond time regime. 11-cis retinal, all-trans retinal and 1,8-diphenyl-1,3,5,7-octatetraene (DPOT) are incorporated into polyethylene films and oriented by stretching the films. By measuring picosecond transient absorption spectra polarized parallel and perpendicular to the stretching direction and calculating the dichroic ratio we get informations about the molecular geometry in excited singlet and triplet states. The results may have relevance to vision.

REDUCED MULTIREFERENCE COUPLED-CLUSTER METHOD AND ITS APPLICATION TO THE PYRIDYNE DIRADICALS

2008 ◽  
Vol 07 (04) ◽  
pp. 805-820 ◽  
Author(s):  
XIANGZHU LI ◽  
JOSEF PALDUS
Keyword(s):  
Molecular Geometry ◽  
External Source ◽  
Cluster Method ◽  
Coupled Cluster ◽  
Triplet States ◽  
Correlation Effects ◽  
Spin Multiplicity ◽  
Triplet Splitting ◽  
Singlet And Triplet States

The reduced multireference (RMR) coupled-cluster (CC) method with singles and doubles (RMR CCSD) that employs a modest-size MR CISD wave function as an external source for the most important (primary) triples and quadruples in order to account for the nondynamic correlation effects in the presence of quasidegeneracy, and which is further perturbatively corrected for the remaining (secondary) triples, RMR CCSD(T), is employed to compute the molecular geometry and the energy of the lowest-lying singlet and triplet states, as well as the corresponding singlet–triplet splitting, for all possible isomers of the m, n-pyridyne diradicals. A comparison is made with earlier results that were obtained by other authors, and the role of the multireference effects for both the geometry and the spin multiplicity of the lowest state, as described by the RMR-type methods, is demonstrated on the example of 2,6- and 3,5-pyridynes.

scholarly journals Transient absorption spectra of triplet states and charge carriers of conjugated polymers

2001 ◽  
Vol 563-564 ◽  
pp. 41-50 ◽  
Author(s):  
H.D. Burrows ◽  
M.da G. Miguel ◽  
A.P. Monkman ◽  
I. Hamblett ◽  
S. Navaratnam
Keyword(s):  
Conjugated Polymers ◽  
Absorption Spectra ◽  
Transient Absorption ◽  
Charge Carriers ◽  
Triplet States ◽  
Transient Absorption Spectra

The bounding energy for singlet and triplet states of the negative muonium ion

2011 ◽  
Vol 30 (0) ◽  
pp. 240-245 ◽  
Author(s):  
М. Гайсак ◽  
М. Гнатич ◽  
Ю. Федорняк
Keyword(s):  
Triplet States ◽  
Singlet And Triplet States

Kinetic-Model-Free Analysis of Transient Absorption Spectra Enabled by 2D Correlation Analysis

2021 ◽  
pp. 4148-4153
Author(s):  
Julian Hniopek ◽  
Carolin Müller ◽  
Thomas Bocklitz ◽  
Michael Schmitt ◽  
Benjamin Dietzek ◽  
...  
Keyword(s):  
Kinetic Model ◽  
Correlation Analysis ◽  
Absorption Spectra ◽  
Transient Absorption ◽  
Transient Absorption Spectra ◽  
Model Free ◽  
2D Correlation Analysis

scholarly journals The role of spin in the degradation of organic photovoltaics

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Ivan Ramirez ◽  
Alberto Privitera ◽  
Safakath Karuthedath ◽  
Anna Jungbluth ◽  
Johannes Benduhn ◽  
...  
Keyword(s):  
Transient Absorption ◽  
Bulk Heterojunction ◽  
Critical Factor ◽  
Model Systems ◽  
Transient Absorption Spectroscopy ◽  
Triplet States ◽  
Paramagnetic Resonance ◽  
Time Resolved ◽  
A Charge

AbstractStability is now a critical factor in the commercialization of organic photovoltaic (OPV) devices. Both extrinsic stability to oxygen and water and intrinsic stability to light and heat in inert conditions must be achieved. Triplet states are known to be problematic in both cases, leading to singlet oxygen production or fullerene dimerization. The latter is thought to proceed from unquenched singlet excitons that have undergone intersystem crossing (ISC). Instead, we show that in bulk heterojunction (BHJ) solar cells the photo-degradation of C60 via photo-oligomerization occurs primarily via back-hole transfer (BHT) from a charge-transfer state to a C60 excited triplet state. We demonstrate this to be the principal pathway from a combination of steady-state optoelectronic measurements, time-resolved electron paramagnetic resonance, and temperature-dependent transient absorption spectroscopy on model systems. BHT is a much more serious concern than ISC because it cannot be mitigated by improved exciton quenching, obtained for example by a finer BHJ morphology. As BHT is not specific to fullerenes, our results suggest that the role of electron and hole back transfer in the degradation of BHJs should also be carefully considered when designing stable OPV devices.

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