全光学的なスイッチングのための歪んだπ系クロモフォール
Guang S He1, Jing Zhu, Alexander Baev
1The Institute for Lasers, Photonics and Biophotonics, State University of New York at Buffalo, Buffalo, New York 14260, USA.
Journal of the American Chemical Society
|April 9, 2011
まとめ
歪んだ分子染色体は,非線形光学特性を有する. この研究は,大きな立方体超偏極性 (γ) と低二光子の吸収を明らかにし,全光学スイッチングアプリケーションにとって有望である.
科学分野:
- 非線形光学は,非線形光学である.
- マテリアルサイエンス 材料科学
- 有機化学 オーガニック・ケミストリー
背景:
- 歪んだπ電子系を持つ分子染色体には,高二次高極化性 (β) が示されている.
- 3次元の非線形光学特性を理解することは,高度な光子装置にとって極めて重要です.
研究 の 目的:
- 歪んだ染色体の立方体高極化 (γ) を調査する.
- 非線形屈折と全光学スイッチングの可能性を評価する.
主な方法:
- 実験的および理論的な研究が行われました.
- 測定は,TMC-2の非線形屈折と2光子の吸収に焦点を当てた.
主要な成果:
- ねじれた染色体には大きな正の立方体超極化性 (γ) があり,自己焦点化につながります.
- 染色体TMC-2は,775 nmで1.87 × 10−13 cm2/Wの大きな非線形屈折指数 (n(2) を示しています.
- 驚くほど低い2フォトンの吸収係数 (0.308のT係数) は,最小限の光学損失を示しています.
結論:
- 単一ビラジカルとズウィテリオン状態が密接に隔てられていることは,観測された非線形光学特性に寄与する.
- これらの歪んだ染色体は,好ましい非線形光学応答により,全光学スイッチングのアプリケーションの有望な候補である.
さらに関連する動画
06:24High-Contrast and Fast Photorheological Switching of a Twist-Bend Nematic Liquid Crystal
Published on: October 31, 2019
12:51A 'Plug and Play' Method to Create Water-dispersible Nanoassemblies Containing an Amphiphilic Polymer, Organic Dyes and Upconverting Nanoparticles
Published on: November 14, 2015
関連する概念動画
01:26Photochemical Electrocyclic Reactions: Stereochemistry
The absorption of UV–visible light by conjugated systems causes the promotion of an electron from the ground state to the excited state. Consequently, photochemical electrocyclic reactions proceed via the excited-state HOMO rather than the ground-state HOMO. Since the ground- and excited-state HOMOs have different symmetries, the stereochemical outcome of electrocyclic reactions depends on the mode of activation; i.e., thermal or photochemical.
Selection Rules: Photochemical Activation
Selection Rules: Photochemical Activation
01:32UV–Vis Spectroscopy of Conjugated Systems
Organic compounds with conjugated double bonds show strong absorption features in the UV–visible region of the electromagnetic spectrum attributed to π → π* electronic excitations. Generally, a UV–vis absorption spectrum is recorded as a plot of absorbance vs wavelength. The wavelength of maximum absorbance, which manifests as a peak in the absorption spectrum, is denoted as λmax.
One of the factors influencing λmax is the extent of conjugation in the...
One of the factors influencing λmax is the extent of conjugation in the...
01:09¹H NMR: Pople Notation
The Pople nomenclature system classifies spin systems based on the difference between their chemical shifts. Coupled spins are denoted by capital letters with subscripts indicating the number of equivalent nuclei. When the coupled nuclei have well-separated chemical shifts, they are assigned letters that are far apart in the alphabet, such as A and X. When the difference in chemical shifts is small, coupled nuclei are named using adjacent letters of the alphabet (AB, MN, or XY).
A proton...
A proton...
02:52Stereoisomerism
Isomerism in Complexes
Isomers are different chemical species that have the same chemical formula.
Transition metal complexes often exist as geometric isomers, in which the same atoms are connected through the same types of bonds but with differences in their orientation in space. Coordination complexes with two different ligands in the cis and trans positions from a ligand of interest form isomers. For example, the octahedral [Co(NH3)4Cl2]+ ion has two isomers (Figure 1) In the cis...
Isomers are different chemical species that have the same chemical formula.
Transition metal complexes often exist as geometric isomers, in which the same atoms are connected through the same types of bonds but with differences in their orientation in space. Coordination complexes with two different ligands in the cis and trans positions from a ligand of interest form isomers. For example, the octahedral [Co(NH3)4Cl2]+ ion has two isomers (Figure 1) In the cis...
01:34Woodward–Hoffmann Selection Rules and Microscopic Reversibility
Electrocyclic reactions, cycloadditions, and sigmatropic rearrangements are concerted pericyclic reactions that proceed via a cyclic transition state. These reactions are stereospecific and regioselective. The stereochemistry of the products depends on the symmetry characteristics of the interacting orbitals and the reaction conditions. Accordingly, pericyclic reactions are classified as either symmetry-allowed or symmetry-forbidden. Woodward and Hoffmann presented the selection criteria for...
01:16UV–Vis Spectroscopy: Molecular Electronic Transitions
In Ultraviolet–Visible (UV–Vis) spectroscopy, the absorption of electromagnetic radiation is used to probe the electronic structure of molecules. This technique provides insights into molecular electronic transitions, particularly the movement of electrons between different molecular orbitals. Radiation is absorbed if the energy of the electromagnetic radiation passing through the molecule is precisely equal to the energy difference between the excited and ground states. During this process,...