scholarly journals Two-photon absorption of the spatially confined LiH molecule

2017 ◽  
Vol 19 (11) ◽  
pp. 7568-7575 ◽  
Author(s):  
Justyna Kozłowska ◽  
Marta Chołuj ◽  
Robert Zaleśny ◽  
Wojciech Bartkowiak
Keyword(s):  
Bond Length ◽  
Lithium Hydride ◽  
Photon Absorption ◽  
Present Contribution ◽  
Two Photon Absorption ◽  
Two Photon ◽  
Length Dependence ◽  
First Time

In the present contribution we study the influence of spatial restriction on the two-photon dipole transitions between the X1Σ+and A1Σ+states of lithium hydride. The bond-length dependence of the two-photon absorption strength is also analyzed for the first time in the literature.

scholarly journals Trans-cis Photoisomerization of a Biomimetic Cyclocurcumin Analogue Rationalized by Molecular Modelling

2021 ◽  
Author(s):  
Raúl Losantos ◽  
Jeremy Pecourneau ◽  
Maxime Mourer ◽  
Stephane Parant ◽  
Andreea Pasc ◽  
...  
Keyword(s):  
Excited States ◽  
Density Functional ◽  
Parent Compound ◽  
Photon Absorption ◽  
Present Contribution ◽  
Two Photon Absorption ◽  
Two Photon ◽  
Photochemical Properties ◽  
A Minor ◽  
Π State

<div> <p>Cyclocurcumin is a natural compound extracted from turmeric and showing, in addition to antiinfective, antibacterial, and intinflammatory capabilities, solvent-dependent phtoswitching ability. The solvent-dependent photochemistry of cyclocurcumin has been rationalized on the basis of a competition between π-π* and n-π* states. Recently we have reported the synthesis of a biomimetic analogue showing enhanced photochemical properties and in particular presenting photoswitching capacity in various media. In the present contribution we rely on the use of molecular modeling and simulation, incuding density functional and wavefunction based methods to explore the excited states potential energy surface landscape. We see that the addition of a carbon-carbon double bond to the core of the natural compounds favors the population of the π-π* state, whatever the choice of the solvent, and hence leads to photoisomerisation, with fluorescence reduced to only a minor channel, rationalizing the experimental observations. In addition, the two photon absorption cross section is also strongly increased compared to the parent compound, paving the way to the use in biologically oriented applications.</p></div>

GIANT TWO-PHOTON ABSORPTION INTO EXCITED STATES OF BIEXCITON

2001 ◽  
Vol 15 (28n30) ◽  
pp. 3765-3768
Author(s):  
I. DMITRUK ◽  
A. KASUYA ◽  
T. GOTO ◽  
Z. YANCHUK
Keyword(s):  
Absorption Spectra ◽  
Excited States ◽  
Direct Method ◽  
Picosecond Laser ◽  
Laser Pulses ◽  
Binding Energies ◽  
Photon Absorption ◽  
Two Photon Absorption ◽  
Two Photon ◽  
First Time

Excited states of excitonic molecule have been observed for the first time by direct method of giant two-photon absorption in monoclinic ZnP 2 single crystal. Two excited states with binding energies 3.3 meV and 1.9 meV have been observed in absorption spectra of intense picosecond laser pulses. First one corresponds to rotational excited state. Interpretation of the second one and details of nonlinear absorption spectra are discussed.

scholarly journals Two-Color Infrared Sensor on the PbTe: In p-n Junction

Sensors ◽  
2021 ◽  
Vol 21 (4) ◽  
pp. 1195
Author(s):  
Jonas Gradauskas ◽  
Bohdan Dzundza ◽  
Leonid Chernyak ◽  
Zinovy Dashevsky
Keyword(s):  
Photovoltaic Effect ◽  
Lead Telluride ◽  
Photon Absorption ◽  
Ir Radiation ◽  
Two Photon Absorption ◽  
Temperature Range ◽  
Two Photon ◽  
Current Voltage ◽  
Current Voltage Characteristics ◽  
First Time

A lead telluride sensor was fabricated on the base of a p-n PbTe junction created on a PbTe single crystal grown by the Czochralski technique, followed by the diffusion of an indium donor impurity into a crystal. The capacitance-voltage and current-voltage characteristics of the sensor were measured over the temperature range from 80 K to 150 K. A prototype of a high-temperature mid-IR sensor, a PbTe diode, with a cut-off wavelength of 4 μm, operating at temperatures up to 150 K, was demonstrated for the first time. The advantage of the sensor is that its operating temperature is high enough to be reached by a solid-state thermoelectric cooler. The sensor showed a specific detectivity value of 1010 cm Hz1/2/W at a temperature of 150 K and a wavelength of 4.2 μm. The possibility to sense pulses of long-IR radiation by means of the PbTe diode was also demonstrated over the 100–180 K temperature range. For the first time, a two-photon absorption-caused photovoltaic effect was observed in PbTe at a wavelength of 9.5 μm at 150 K.

scholarly journals Trans-cis Photoisomerization of Biomimetic Cyclocurcumin Analogous Rationalized by Molecular Modelling

2021 ◽  
Author(s):  
Raúl Losantos ◽  
Jeremy Pecourneau ◽  
Maxime Mourer ◽  
Stephane Parant ◽  
Andreea Pasc ◽  
...  
Keyword(s):  
Excited States ◽  
Density Functional ◽  
Parent Compound ◽  
Photon Absorption ◽  
Present Contribution ◽  
Two Photon Absorption ◽  
Two Photon ◽  
Photochemical Properties ◽  
A Minor ◽  
Π State

Cyclocurcumin is a natural compound extracted from turmeric and showing, in addition to antiinfective, antibacterial, and intinflammatory capabilities, solvent-dependent phtoswitching ability. The solvent-dependent photochemistry of cyclocurcumin has been rationalized on the basis of a competition between π-π* and n-π* states. Recently we have reported the synthesis of a biomimetic analogous showing enhanced photochemical properties and in particular presenting photoswitching capacity in various media. In the present contribution we rely on the use of molecular modeling and simulation, incuding density functional and wavefunction based methods to explore the excited states potential energy surface landscape. We see that the addition of a carbon-carbon double bond to the core of the natural compounds favors the population of the π-π* state, whatever the choice of the solvent, and hence leads to photoisomerisation, with fluorescence reduced to only a minor channel, rationalizing the experimental observations. In addition, the two photon absorption cross section is also strongly increased compared to the parent compound, paving the way to the use in biologically oriented applications.

scholarly journals Trans-cis Photoisomerization of a Biomimetic Cyclocurcumin Analogue Rationalized by Molecular Modelling

2021 ◽  
Author(s):  
Raúl Losantos ◽  
Jeremy Pecourneau ◽  
Maxime Mourer ◽  
Stephane Parant ◽  
Andreea Pasc ◽  
...  
Keyword(s):  
Excited States ◽  
Density Functional ◽  
Parent Compound ◽  
Photon Absorption ◽  
Present Contribution ◽  
Two Photon Absorption ◽  
Two Photon ◽  
Photochemical Properties ◽  
A Minor ◽  
Π State

<div> <p>Cyclocurcumin is a natural compound extracted from turmeric and showing, in addition to antiinfective, antibacterial, and intinflammatory capabilities, solvent-dependent phtoswitching ability. The solvent-dependent photochemistry of cyclocurcumin has been rationalized on the basis of a competition between π-π* and n-π* states. Recently we have reported the synthesis of a biomimetic analogue showing enhanced photochemical properties and in particular presenting photoswitching capacity in various media. In the present contribution we rely on the use of molecular modeling and simulation, incuding density functional and wavefunction based methods to explore the excited states potential energy surface landscape. We see that the addition of a carbon-carbon double bond to the core of the natural compounds favors the population of the π-π* state, whatever the choice of the solvent, and hence leads to photoisomerisation, with fluorescence reduced to only a minor channel, rationalizing the experimental observations. In addition, the two photon absorption cross section is also strongly increased compared to the parent compound, paving the way to the use in biologically oriented applications.</p></div>

Soluble meso-tetrakis(arylethynyl)porphyrins — synthesis and optical properties

2014 ◽  
Vol 18 (10n11) ◽  
pp. 998-1013 ◽  
Author(s):  
Agnieszka Nowak-Król ◽  
Łukasz G. Łukasiewicz ◽  
Joy E. Haley ◽  
Mikhail Drobizhev ◽  
Aleksander Rebane ◽  
...  
Keyword(s):  
Optical Properties ◽  
Red Light ◽  
Photon Absorption ◽  
Two Photon Absorption ◽  
Two Photon ◽  
Resonance Enhancement ◽  
Order Of Magnitude ◽  
Homo And Lumo ◽  
The One ◽  
First Time

Trans- A 2 B 2-tetrakis(arylethynyl)porphyrins with suitable solubility in CH 2 Cl 2, CHCl 3, EtOAc , acetone and toluene have been obtained for the first time. Among two possible strategies the one comprising the synthesis of 5,15-dibromo-10,20-bis[(isopropylsilyl)ethynyl]porphyrin proved to be more efficient. The pathway towards densely substituted arylacetylenes has been optimized. The use of previously identified 3,4,5-trialkoxyaryl substituent was crucial for achieving the reasonable solubility. The optical properties of meso-substituted tetrakis(arylethynyl)porphyrins were studied showing that strong polarization imparted by direct conjugation of all four substituents with porphyrin core resulted not only in strong absorption of red light but also in a relatively long triplet lifetime. Meso-tetrakis(arylethynyl)porphyrins have a significantly longer lifetime of T1 state than bis(arylethynyl)porphyrins and in their case all the states are mixtures of transitions between the HOMO-1, HOMO and LUMO, LUMO+1 MOs. We show that the presence of two additional arylethynyl substituents at meso-positions enhance the maximum two-photon absorption cross-section of trans- A 2 B 2-tetrakis(arylethynyl)porphyrins by more than one order of magnitude. Maximum values as high as σ2 = 500 GM at 950 nm result from realization of suitable conditions for effective resonance enhancement along with a lowering of the energy and intensification of the two-photon allowed transitions in the Soret region.

Three- and two-photon absorption spectroscopy: REMPI of HCl and HBr

2001 ◽  
Vol 79 (2-3) ◽  
pp. 197-210 ◽  
Author(s):  
Á. Kvaran ◽  
H Wang ◽  
B G Waage
Keyword(s):  
Absorption Line ◽  
Line Strength ◽  
Multiphoton Ionization ◽  
Photon Absorption ◽  
Excitation Process ◽  
Two Photon Absorption ◽  
Two Photon ◽  
Population Distributions ◽  
Photon Excitation ◽  
First Time

Approximation expressions for absorption line strengths due to Ω' = 0,1,2,3 ¬ Ω" = 0 (Σ, Π, Δ, and Φ ¬ Σ) transitions for three-, two-, and one-photon absorptions are summarized. Those for three- and two-photon absorptions are used to analyse room temperature (3+1) and (2+1) REMPI (resonance enhanced multiphoton ionization) spectra due to transitions to Rydberg states in HCl and HBr to give spectroscopic parameters. A mechanism of the three-photon excitation process for the (E1 Σ+) ¬ X(1Σ+), (0,0) transition in HCl is proposed. A Rydberg state, not observed in single- or two-photon absorption, with a band origin at 80 167 cm-1 was identified in (3+1) REMPI of HBr and analysed for the first time. It was assigned to the l(3(Φ(Ω' = 3)) ((σ2π3)5dδ) state, (0,0) band. Use of the three-photon absorption line strength expressions for deriving rotational population distributions in ground-state HBr is demonstrated. PACS Nos.: 03.40Kf, 42.65Tg, 42.81Dp

scholarly journals Trans-cis Photoisomerization of Biomimetic Cyclocurcumin Analogous Rationalized by Molecular Modelling

2021 ◽  
Author(s):  
Raúl Losantos ◽  
Jeremy Pecourneau ◽  
Maxime Mourer ◽  
Stephane Parant ◽  
Andreea Pasc ◽  
...  
Keyword(s):  
Excited States ◽  
Density Functional ◽  
Parent Compound ◽  
Photon Absorption ◽  
Present Contribution ◽  
Two Photon Absorption ◽  
Two Photon ◽  
Photochemical Properties ◽  
A Minor ◽  
Π State

Cyclocurcumin is a natural compound extracted from turmeric and showing, in addition to antiinfective, antibacterial, and intinflammatory capabilities, solvent-dependent phtoswitching ability. The solvent-dependent photochemistry of cyclocurcumin has been rationalized on the basis of a competition between π-π* and n-π* states. Recently we have reported the synthesis of a biomimetic analogous showing enhanced photochemical properties and in particular presenting photoswitching capacity in various media. In the present contribution we rely on the use of molecular modeling and simulation, incuding density functional and wavefunction based methods to explore the excited states potential energy surface landscape. We see that the addition of a carbon-carbon double bond to the core of the natural compounds favors the population of the π-π* state, whatever the choice of the solvent, and hence leads to photoisomerisation, with fluorescence reduced to only a minor channel, rationalizing the experimental observations. In addition, the two photon absorption cross section is also strongly increased compared to the parent compound, paving the way to the use in biologically oriented applications.

Investigation of the nonlinear absorption spectrum of all-trans retinoic acid by using the steady and transient two-photon absorption spectroscopy

RSC Advances ◽  
2015 ◽  
Vol 5 (91) ◽  
pp. 74531-74538 ◽  
Author(s):  
M. G. Vivas ◽  
J. P. Siqueira ◽  
D. L. Silva ◽  
L. de Boni ◽  
C. R. Mendonca
Keyword(s):  
Absorption Spectrum ◽  
Retinoic Acid ◽  
Excited State ◽  
Photon Absorption ◽  
Two Photon Absorption ◽  
Two Photon ◽  
Trans Retinoic Acid ◽  
All Trans Retinoic Acid ◽  
Complete Study ◽  
First Time

This paper reports for the first time a complete study on the steady and transient excited state dynamics induced by 2PA for ATRA.

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