合成小分子の1次元のランダムな歩行が熱力学的シンクに向かっている
Araceli G Campaña1, David A Leigh, Urszula Lewandowska
1School of Chemistry, University of Edinburgh, The King's Buildings, West Mains Road, Edinburgh EH9 3JJ, United Kingdom.
Journal of the American Chemical Society
|May 16, 2013
まとめ
この研究は,オリゴエチレンイミン鎖に沿ってα-メチレン-4-ニトロスティレンの動きを示しています. 分子は分子である.
科学分野:
- 超分子化学 超分子化学
- ポリマー化学のポリマー化学について
- 化学ダイナミクス 化学ダイナミクス
背景:
- オリゴエチレンイミンは,分子移動のための軌道を提供します.
- α-メチレン-4-ニトロチレンは分子ウォーカーとして作用する.
研究 の 目的:
- オリゴエチレンイミンの経路に沿ったα-メチレン-4-ニトロスティレンの自発的な分子内移動を調査する.
- この分子移動の位置性イソメリズムとダイナミクスを特徴づけるために.
主な方法:
- 異なる長さ (n=3,5,9) のオリゴエチレンイミン線路の合成
- (1) H NMRスペクトロスコーピーを用いてポジショナルの同位体をモニタリングする.
- ウォーカーのダイナミクスを記述するためにランダムウォークモデルを適用する.
主要な成果:
- 移動を可能にする反転可能な分子内ミカエル-レトロ-ミカエル反応が観察されました.
- n=3 と n=5.5 の定量化された位置性同位体群.
- ナフチルメチラミン群を熱力学的シンクとして識別し,分布をバイアスした.
- 移住のダイナミクスが1Dブラウンのランダムウォークモデルに従っていることを実証しました.
結論:
- オリゴエチレンイミンの痕跡は,制御された分子移動を促進します.
- ナフチルメチラミンエンドグループは,分子ウォーカーを効果的に捕まえる.
- 観測された動力は,ブラウンの運動によって正確にモデル化されています.
さらに関連する動画
09:17Structure-Based Simulation and Sampling of Transcription Factor Protein Movements along DNA from Atomic-Scale Stepping to Coarse-Grained Diffusion
Published on: March 1, 2022
11:03An Analog Macroscopic Technique for Studying Molecular Hydrodynamic Processes in Dense Gases and Liquids
Published on: December 4, 2017
関連する概念動画
01:29Reaction Mechanisms: Rate-limiting Step Approximation
The rate-determining step, or RDS, in a chemical reaction is the slowest step that determines the overall reaction rate. It is identified by using the observed rate law and typically involves approximation methods like the RDS approximation or the steady-state approximation.In the RDS approximation, also known as the rate-limiting-step or equilibrium approximation, the reaction mechanism consists of one or more reversible reactions near equilibrium, followed by a slower RDS, and then one or...
02:49Second Law of Thermodynamics
In the quest to identify a property that may reliably predict the spontaneity of a process, a promising candidate has been identified: entropy. Processes that involve an increase in entropy of the system (ΔS > 0) are very often spontaneous; however, examples to the contrary are plentiful. By expanding consideration of entropy changes to include the surroundings, a significant conclusion regarding the relation between this property and spontaneity may be reached. In thermodynamic models, the...
02:39Entropy
Salt particles that have dissolved in water never spontaneously come back together in solution to reform solid particles. Moreover, a gas that has expanded in a vacuum remains dispersed and never spontaneously reassembles. The unidirectional nature of these phenomena is the result of a thermodynamic state function called entropy (S). Entropy is the measure of the extent to which the energy is dispersed throughout a system, or in other words, it is proportional to the degree of disorder of a...
02:59The Nernst Equation
Nonstandard Reaction Conditions
The interconnection between standard cell potentials and various thermodynamic parameters such as the standard free energy change ΔG° and equilibrium constant K has been previously explored. For example, a redox reaction involving zinc(II) and tin(II) ions at 1 M concentration with Eºcell = +0.291 V and ΔG° = −56.2 kJ is spontaneous.
The interconnection between standard cell potentials and various thermodynamic parameters such as the standard free energy change ΔG° and equilibrium constant K has been previously explored. For example, a redox reaction involving zinc(II) and tin(II) ions at 1 M concentration with Eºcell = +0.291 V and ΔG° = −56.2 kJ is spontaneous.
03:08Rate-Determining Steps
Relating Reaction Mechanisms
In a multistep reaction mechanism, one of the elementary steps progresses significantly slower than the others. This slowest step is called the rate-limiting step (or rate-determining step). A reaction cannot proceed faster than its slowest step, and hence, the rate-determining step limits the overall reaction rate.
The concept of rate-determining step can be understood from the analogy of a 4-lane freeway with a short-stretch of traffic-bottleneck caused due to...
In a multistep reaction mechanism, one of the elementary steps progresses significantly slower than the others. This slowest step is called the rate-limiting step (or rate-determining step). A reaction cannot proceed faster than its slowest step, and hence, the rate-determining step limits the overall reaction rate.
The concept of rate-determining step can be understood from the analogy of a 4-lane freeway with a short-stretch of traffic-bottleneck caused due to...
01:12Diffusion
Diffusion is the passive movement of substances down their concentration gradients—requiring no expenditure of cellular energy. Substances, such as molecules or ions, diffuse from an area of high concentration to an area of low concentration in the cytosol or across membranes. Eventually, the concentration will even out, with the substance moving randomly but causing no net change in concentration. Such a state is called dynamic equilibrium, which is essential for maintaining overall...