吸附诱导的不对称组件从一个阿奇拉尔吸附剂
Yuguang Cai1, Steven L Bernasek
1Department of Chemistry, Princeton University, Princeton, New Jersey 08540, USA.
Journal of the American Chemical Society
|October 28, 2004
概括
阿基拉分子在石墨表面上形成不对称的结构. 这种由基板相互作用驱动的自组装单层 (SAM) 扭曲,是表面科学中的新发现.
科学领域:
- 表面科学是一门学科.
- 超分子化学 超分子化学
- 材料科学 材料科学 材料科学
背景情况:
- 自组装单层 (SAM) 是在表面上有序的分子组件.
- 阿基拉分子在吸附时通常形成对称结构.
- 基板-表面相互作用可以影响吸附剂的形状和对称性.
研究的目的:
- 为了研究在石墨上的1-octadecanol SAMs中的对称性破坏.
- 了解吸附引起的结构扭曲的机制.
- 为了探索从非体构建块中形成的超分子不对称性.
主要方法:
- 在液体/固体界面使用扫描道显微镜 (STM).
- 在高度排序的 pyrolytic 石墨 (HOPG) 上分析了 1-octadecanol 的自组合单层结构.
- 观察到的分子构造和单元细胞排列.
主要成果:
- 在HOPG.上观察到1-octadecanol SAM结构中的对称性破坏.
- 由于格子不匹配,证明了链的不对称扭曲.
- 鉴定出一个形单元细胞,由于键的要求导致了不对称的扭曲.
结论:
- 这项研究提供了吸附诱导扭曲的第一个例子,它从一个Achiral表面上的Achiral分子中形成了一个超分子不对称的结构.
- 观察到的不对称性来自于吸附剂对基质的反应,导致与溶液中的分子不同的构造.
- 这一发现为控制分子自我组装和从achiral前体中创建奇拉结构提供了新的见解.
相关概念视频
01:29Drug-Receptor Interactions
Drug-receptor interaction describes the binding of receptors by drugs, but not all drug-receptor interactions result in activation and tissue response. For instance, the binding of agonists activates the receptor to generate a cellular reaction, while antagonists bind to receptors without causing their activation.
Several parameters, such as the drug's affinity for its receptor and its efficacy, which is its ability to activate the receptor, determine the drug's effect on the tissue.
Several parameters, such as the drug's affinity for its receptor and its efficacy, which is its ability to activate the receptor, determine the drug's effect on the tissue.
01:25Drug-Receptor Interaction: Agonist
Agonists are drugs that interact with specific receptors in the body to produce a biological response. When an agonist binds to a receptor, it activates or enhances the receptor's function, leading to physiological effects. The interaction between agonist drugs and receptors is crucial for their therapeutic action in various medical treatments.
Agonists can bind to receptors in different ways. Some agonists bind directly to the receptor's active site, mimicking the endogenous ligand's action.
Agonists can bind to receptors in different ways. Some agonists bind directly to the receptor's active site, mimicking the endogenous ligand's action.
01:28Drug-Receptor Interaction: Antagonist
An antagonist is a drug that binds strongly to a receptor without activating it. An antagonist prevents other molecules, such as neurotransmitters or hormones, from binding to the receptor and triggering a cellular response. Such interaction effectively hinders the normal physiological processes mediated by the receptor, resulting in various pharmacological effects depending on the specific receptor targeted.
Antagonists can be classified as competitive or noncompetitive based on their...
Antagonists can be classified as competitive or noncompetitive based on their...
01:30Combined Effects of Drugs: Antagonism
The combined effects of drugs can result in various interactions, of which an important type is antagonism. Antagonism is a mechanism where one drug inhibits or counteracts the effects of another drug. Antagonism can occur through various means, including receptor binding, allosteric modulation, functional interaction, chemical reactions, and pharmacokinetic processes.
The most common type is receptor antagonism, where one drug acts as an antagonist to block the effects of another drug by...
The most common type is receptor antagonism, where one drug acts as an antagonist to block the effects of another drug by...
01:25Adrenergic Agonists: Indirect-Acting Agents
Indirect-acting adrenergic agonists potentiate the effects of endogenous catecholamines through different mechanisms without directly binding to adrenoceptors.
One mechanism involves depleting stored catecholamines by displacing them from synaptic vesicles. These agents, known as "displacers," are transported into vesicles at the expense of noradrenaline. Examples include amphetamine and tyramine, which lack a catechol moiety, resulting in prolonged action, improved oral bioavailability, and...
One mechanism involves depleting stored catecholamines by displacing them from synaptic vesicles. These agents, known as "displacers," are transported into vesicles at the expense of noradrenaline. Examples include amphetamine and tyramine, which lack a catechol moiety, resulting in prolonged action, improved oral bioavailability, and...
01:16Adrenergic Agonists: Chemistry and Structure-Activity Relationship
Adrenergic agonists' structure-activity relationship (SAR) determines their selectivity and efficacy. These agonists comprise a phenylethylamine moiety with an aromatic ring and an ethylamine side chain.
Aromatic ring substitutions: Substituting the aromatic ring with –OH groups at positions 3 and 4 yields catecholamines (e.g., epinephrine), which have a high affinity for adrenoceptors. Hydrogen bonding between –OH groups and receptors enhances adrenergic activity.
Separation of the aromatic...
Aromatic ring substitutions: Substituting the aromatic ring with –OH groups at positions 3 and 4 yields catecholamines (e.g., epinephrine), which have a high affinity for adrenoceptors. Hydrogen bonding between –OH groups and receptors enhances adrenergic activity.
Separation of the aromatic...