scholarly journals Influence of Membrane Phase on the Optical Properties of DPH

Molecules ◽  
2020 ◽  
Vol 25 (18) ◽  
pp. 4264
Author(s):  
Silvio Osella ◽  
Markéta Paloncýová ◽  
Maryam Sahi ◽  
Stefan Knippenberg
Keyword(s):  
Optical Properties ◽  
Absorption Spectra ◽  
Fluorescence Anisotropy ◽  
Rayleigh Scattering ◽  
Molecular Conformation ◽  
Dipole Moments ◽  
Photon Absorption ◽  
Molecular Mechanics Calculations ◽  
Fluorescence Anisotropy Decay ◽  
Transition Dipole

The fluorescent molecule diphenylhexatriene (DPH) has been often used in combination with fluorescence anisotropy measurements, yet little is known regarding the non-linear optical properties. In the current work, we focus on them and extend the application to fluorescence, while paying attention to the conformational versatility of DPH when it is embedded in different membrane phases. Extensive hybrid quantum mechanics/molecular mechanics calculations were performed to investigate the influence of the phase- and temperature-dependent lipid environment on the probe. Already, the transition dipole moments and one-photon absorption spectra obtained in the liquid ordered mixture of sphingomyelin (SM)-cholesterol (Chol) (2:1) differ largely from the ones calculated in the liquid disordered DOPC and solid gel DPPC membranes. Throughout the work, the molecular conformation in SM:Chol is found to differ from the other environments. The two-photon absorption spectra and the ones obtained by hyper-Rayleigh scattering depend strongly on the environment. Finally, a stringent comparison of the fluorescence anisotropy decay and the fluorescence lifetime confirm the use of DPH to gain information upon the surrounding lipids and lipid phases. DPH might thus open the possibility to detect and analyze different biological environments based on its absorption and emission properties.

Theoretical study on nonlinear optical properties of N-(6-hydroxyhexyl)-5-nitroazophenyl carbazole

2018 ◽  
Vol 27 (04) ◽  
pp. 1850036
Author(s):  
Quanjie Zhong ◽  
Jian Zheng ◽  
Lin Zhang ◽  
Xuan Luo
Keyword(s):  
Optical Properties ◽  
Charge Transfer ◽  
Excited States ◽  
Density Functional ◽  
Nonlinear Optical ◽  
Dipole Moments ◽  
Electron Excitation ◽  
Nonlinear Optical Properties ◽  
Transition Dipole ◽  
Leading Role

The first-, second- and third-order nonlinear optical properties of N-(6-hydroxyhexyl)-5-nitroazophenyl carbazole in gas phase employing sum-over-states (SOS) method have been calculated for the first time. The ground state molecular structure of N-(6-hydroxyhexyl)-5-nitroazophenyl carbazole was obtained by the geometrical optimizations based on the B3LYP/6-31[Formula: see text]G(d) level. The energy of excited states and transition dipole moments between different excited states were obtained by using the time-dependent density functional theory (TDDFT) based on the CAM-B3LYP/Sadlej POL level. Charge transfer during electron excitation was analyzed based on hole and electron distributions. Our calculations showed that the N-(6-hydroxyhexyl)-5-nitroazophenyl carbazole has good nonlinear optical properties and its nonlinear optical properties arise from charge-transfer excitation and local excitation but charge transfer plays the leading role.

Substituent effects on linear and nonlinear optical properties of fluorescent (E)-2-(4-halophenyl)-7-arlstyrylimidazo[1,2-A]pyridine: spectroscopic and computational methods

2018 ◽  
Vol 4 (4) ◽  
Author(s):  
Siddheshwar D. Jadhav ◽  
Ponnadurai Ramasami ◽  
Nagaiyan Sekar
Keyword(s):  
Optical Properties ◽  
Excited State ◽  
Nonlinear Optical ◽  
Dipole Moments ◽  
Nonlinear Optical Properties ◽  
Photon Absorption ◽  
Degree Of Polarization ◽  
Hammett Constant ◽  
Linear And Nonlinear ◽  
The Difference

Abstract Effects of alkylamino and bromo substituents on imidazo[1,2-a]pyridines containing donor-π-acceptor type groups were comprehensively investigated for their linear and nonlinear optical properties by solvatochromic and DFT (CAM-B3LYP and BHandHLYP) methods. The difference between the ground and excited dipole moments as well as their ratios obtained by solvatochromic analysis indicate that the excited state is more polar than the ground state for both the bromo and diethyl amino derivative. More than twofold enhancement in the excited state dipole moments was observed as revealed by the difference and ratio of dipole moment upon the introduction of alkylamino donor group and these suggest large intramolecular charge transfer in the dyes. Stabilization energy above 20 kJ/mol was observed for large number of electron donor–acceptor interactions in Natural Bonding Orbital (NBO) analysis. Bond length alternation (BLA) and Bond order alternation (BOA) values tend to zero suggesting a high degree of polarization in the dyes. Enhancement in mean polarizability (α0), first hyperpolarizability (β0) and second static hyperpolarizabilities ( $\bar \gamma$) were observed by the introduction of alkylamino and bromo group in place of chloro in spite of the fact that Hammett constant of chloro and bromo are the same. The dyes have fundamental and intrinsic properties within the Hamiltonian limits. The two-photon absorption cross section value (≈100 GM) is comparable with LDS-698, a commercial TPA dye. This investigation is important for understanding the electronic structure of imidazo[1,2-a]pyridine with active functional groups and extending the potential for optical applications.

Cylindrical Aggregates of TDBC: Linear and Nonlinear Optical Properties Versus Morphology

2004 ◽  
Vol 97-98 ◽  
pp. 201-206 ◽  
Author(s):  
A. Pugžlys ◽  
P.R. Hania ◽  
C. Didraga ◽  
J. Knoester ◽  
K. Duppen
Keyword(s):  
Optical Properties ◽  
Nonlinear Optical ◽  
Dipole Moments ◽  
Nonlinear Optical Properties ◽  
Exciton Band ◽  
Absorption Bands ◽  
Linear Absorption ◽  
Transition Dipole ◽  
Linear And Nonlinear ◽  
Double Wall

The linear and nonlinear optical properties of pure 3,3'-bis(3-carboxypropyl)-5,5',6,6'- tetrachloro-1,1'-dioctylbenzimidacarbocyanine (C8O3) aggregates as well as of C8O3 aggregates in the presence of PVA are studied at room temperature. The obtained results reveal that absorption spectra of both aggregates are governed by four absorption bands. Three of these represent transitions having dipole moments oriented parallel to the axis of the aggregate and one oriented perpendicular to it. The two lower energy parallel transitions are found to be weakly coupled which suggests that they represent two excitons located on different walls of the double-wall cylinder. In contrast, the lowest energy parallel transition and the transition having a transition dipole moment oriented perpendicular to the aggregate axis share the same ground state which reveals that they belong to the same exciton band. The manner of modification of the linear absorption with addition of PVA as well as the similarity of the pump-probe spectra of the two investigated aggregates suggests that this exciton band originates from the inner wall of the double-wall cylinder.

Ab Initio Design of Two-Photon Absorbing Materials

1999 ◽  
Vol 597 ◽  
Author(s):  
Paul N. Day ◽  
Kiet A. Nguyen ◽  
Ruth Pachter
Keyword(s):  
Excited State ◽  
Ab Initio ◽  
Nonlinear Optical ◽  
Dipole Moments ◽  
Transition Dipole Moment ◽  
Photon Absorption ◽  
Transition Dipole ◽  
Two Photon Absorption ◽  
Two Photon ◽  
Absorbing Materials

AbstractTwo-photon absorbing materials such as conjugated polyenes show promise as nonlinear optical materials. Prediction of two-photon absorption frequencies and cross-sections has been limited by the high level of ab initio calculations that must be carried out in order to accurately calculate excited state energies and transition dipole moments, by the size of many of the compounds of interest, and by the difficulty of handling condensed phase effects in the calculations. We have carried out geometry optimizations at the multi-configurational selfconsistent field level on a small polyene, hexatriene, both in the gas-phase and in solution, with the solvent effects being modeled by the effective fragment potential. The excited-state energies have been calculated by the multiconfigurational quasidegenerate perturbation theory. Transition dipole moment calculations have also been carried out, from which the two-photon absorption cross-section can be estimated. The results indicate that just one or two solvent molecules can have a large effect on the nonlinear optical properties of two-photon absorbing materials.

THEORETICAL STUDIES OF ONE- AND TWO-PHOTON ABSORPTION PROPERTIES FOR SYMMETRIC MOLECULES BASED ON BIS(STILBENE)DIETHYLENE

2006 ◽  
Vol 05 (03) ◽  
pp. 535-542 ◽  
Author(s):  
SHU-LAN ZHOU ◽  
XIAN ZHAO ◽  
XUE-QIN SUN ◽  
XIU-FENG CHENG
Keyword(s):  
Excited State ◽  
Cross Sections ◽  
Dipole Moments ◽  
Photon Absorption ◽  
Absorption Properties ◽  
Final State ◽  
Transition Dipole ◽  
Two Photon Absorption ◽  
Two Photon ◽  
Acceptor Side

In order to investigate the substituting effects on the two-photon absorption (TPA) cross-section and the position of the TPA peak, the one- and two-photon absorption properties of a series of symmetric molecules with bis(stilbene)diethylene π-conjugated bridge have been studied using ZINDO-SOS method. The transition moments from the ground state to the lowest excited state (M0k) and from the lowest excited state to the TPA final state (Mkn), together with the detuning energy ΔE = E0k - Ekn/2, were calculated using the INDO1 method included in the ZINDO program. The results indicate that bis-donor and bis-acceptor substitutions mainly affect the transition dipole moments M0k and Mkn, and that donor or acceptor side groups have a strong influence on the detuning energy. Meanwhile, it was found that the molecules with the bis-donor structure possess enhanced TPA cross sections, and the molecules with cyano or methoxy side groups have a large red-shift with respect to molecules without side groups.

scholarly journals π–π-Induced aggregation and single-crystal fluorescence anisotropy of 5,6,10b-triazaacephenanthrylene

IUCrJ ◽  
2018 ◽  
Vol 5 (3) ◽  
pp. 335-347 ◽  
Author(s):  
Katarzyna Ostrowska ◽  
Davide Ceresoli ◽  
Katarzyna Stadnicka ◽  
Marlena Gryl ◽  
Marco Cazzaniga ◽  
...  
Keyword(s):  
Dipole Moment ◽  
Single Crystal ◽  
Fluorescence Anisotropy ◽  
Dipole Moments ◽  
Emission Spectra ◽  
Permanent Dipole Moment ◽  
Transition Dipole ◽  
Absorption And Emission ◽  
Covalent Interaction ◽  
Induced Aggregation

The structural origin of absorption and fluorescence anisotropy of the single crystal of the π-conjugated heterocyclic system 5,6,10b-triazaacephenanthrylene, TAAP, is presented in this study. X-ray analysis shows that the crystal framework in the space group P\overline{1} is formed by centrosymmetric dimers of face-to-face mutually oriented TAAP molecules joined by π–π non-covalent interactions. The conformation of the TAAP molecule is stabilized by intramolecular C—H...N(sp 2), N(sp 2)H...π(CN), and C—H...O(sp 2) hydrogen bonds. The presence of weak π–π interactions is confirmed by quantum theory of atoms in molecules (QTAIM) and non-covalent interaction (NCI) analysis. The analysis of the optical spectra of TAAP in solution and in the solid state does not allow the specification of the aggregation type. DFT calculations for the dimer in the gas phase indicate that the lowest singlet excitation is forbidden by symmetry, suggesting H-type aggregation, even though the overall absorption spectrum is bathochromically shifted as for the J-type. The experimental determination of the permanent dipole moment of a TAAP molecule in 1,4-dioxane solution indicates the presence of the monomer form. The calculated absorption and emission spectra of the crystal in a simple approximation are consistent with the experimentally determined orientation of the absorption and emission transition dipole moments in TAAP single crystals. The electrostatic interaction between monomers with a permanent dipole moment (ca 4 D each) could result in the unusual spectroscopic JH-aggregate behaviour of the TAAP dimer.

Organometallic Complexes for Non-Linear Optics. 51. Second- and Third-Order Non-Linear Optical Properties of Alkynylgold Complexes

2012 ◽  
Vol 65 (7) ◽  
pp. 834 ◽  
Author(s):  
Adam Barlow ◽  
Bandar Babgi ◽  
Marek Samoc ◽  
T. Christopher Corkery ◽  
Stijn van Cleuvenbergen ◽  
...  
Keyword(s):  
Optical Properties ◽  
Rayleigh Scattering ◽  
Organometallic Complexes ◽  
Photon Absorption ◽  
Imaginary Component ◽  
Linear Optics ◽  
Non Linear Optics ◽  
Non Linear ◽  
Linear Optical Properties ◽  
Linear Optical

The alkynes HC≡CC6H2-2,6-Et2-4-C≡CC6H4-4-NO2 (4) and HC≡CC6H4-4-C≡CC6H2-2,6-Et2-4-C≡CC6H4-4-NO2 (6) and gold alkynyl complexes Au{C≡CC6H2-2,5-(OEt)2-4-C≡CC6H4-4-NO2}(PPh3) (7), Au(C≡CC6H2-2,6-Et2-4-C≡CC6H4-4-NO2)(PPh3) (8), and Au(C≡CC6H4-4-C≡CC6H2-2,6-Et2-4-C≡CC6H4-4-NO2)(PPh3) (9) have been synthesized. The linear optical properties and quadratic optical non-linearities of 7–9 have been measured, the latter by hyper-Rayleigh scattering at 1064 nm, and compared with data for the previously reported complexes Au(C≡CC6H4-4-NO2)(PPh3) (10) and Au(C≡CC6H4-4-C≡CC6H4-4-NO2)(PPh3) (11). The optical absorption maximum red-shifts and the first hyperpolarizabilities increase on π-system lengthening and on introduction of electron-releasing substituents on the π-bridge ring adjacent to the metal centre. The cubic non-linear optical properties of 1,4-{(PCy3)Au(C≡C)}2C6H4 (12) and {(PCy3)Au(C≡C-4-C6H4C≡C)}6C6 (13) have been assessed by wide spectroscopic range femtosecond Z-scan studies; the maximal values of the imaginary component and the effective two-photon absorption cross-section increase markedly on proceeding from linear complex 12 to 6-fold-symmetric complex 13, an increase that is maintained when data are scaled by relative molecular weight.

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