関連する実験動画
Updated: Jun 9, 2026
11:00
Determination of the Gas-phase Acidities of Oligopeptides
Published on: June 24, 2013
ナトリウムダイアルキルアミドジンケート:アルキル基またはアミド基. 実験的・理論的なケーススタディ
Prokopis C Andrikopoulos1, David R Armstrong, Helen R L Barley
1Department of Pure and Applied Chemistry, University of Strathclyde, Glasgow G1 1XL, UK.
Journal of the American Chemical Society
|April 28, 2005
まとめ
新しい亜鉛酸ナトリウム反応剤[TMEDA.Na(mu-tBu) ((mu-TMP) Zn(tBu) ]が合成され,特徴づけられました. このアルカリ金属亜鉛酸は,水素金属交換反応においてアルキル基として作用し,熱力学的要因によるユニークな反応性を示しています.
科学分野:
- 有機金属化学 有機金属化学
- メイングループ化学
背景:
- アルカリ金属亜鉛酸塩は,水素金属およびハロゲン金属相互変換反応においてユニークな反応性と選択性を示しています.
- ヘテロレプティックなダイオルガノ-アミドシンケートは,これらの変換において特に有用である.
研究 の 目的:
- 価値ある試薬として,新しいナトリウムTMP-亜鉛添加物[TMEDA.Na(mu-tBu) ((mu-TMP) Zn ((tBu)) ]を導入する.
- 水素金属交換反応におけるその構造,反応性,およびメカニズム的側面を調査する.
主な方法:
- tBu2Zn,NaTMP,TMEDAからナトリウムTMP-亜鉛アダクトを合成する.
- 1Hと13CのNMRスペクトロスコピーとX線結晶学を用いた特徴付け.
- ベンゼンとの反応による反応性の調査とDFT計算.
主要な成果:
- 新型亜鉛酸ナトリウム[TMEDA.Na(mu-tBu) ((mu-TMP) Zn(tBu) ]は,58%の収量で合成され,構造的に特徴づけられました.
- X線結晶学では,非対称なtBuブリッジとNa...Meアゴスティックコンタクトを持つ5つ構成のリングシステムが発見されました.
- 亜鉛酸塩は,ベンゼンと水素金属交換においてアルキル基として機能し,TMEDA.Na.mu-Ph.mu-TMP.Zn.tBu.を形成する.
- DFT計算は,熱力学的要因が tBu リガンド転送を好むことを示唆しています.
結論:
- 新しいナトリウムTMP-亜鉛酸は,安定した,合成的に利用可能な反応剤です.
- 水素金属交換におけるアルキル塩基としてのその反応性は確認され,機械的に説明されています.
- この研究は,合成化学におけるアルカリ金属亜鉛酸塩の範囲を拡大します.
さらに関連する動画
08:03Multi-analyte Biochip (MAB) Based on All-solid-state Ion-selective Electrodes (ASSISE) for Physiological Research
Published on: April 18, 2013
08:27Analysis of Effect of Compound Salt Stress on Seed Germination and Salt Tolerance Analysis of Pepper (Capsicum annuum L.)
Published on: November 30, 2022
関連する概念動画
02:54Ions as Acids and Bases
Salts with Acidic Ions
Salts are ionic compounds composed of cations and anions, either of which may be capable of undergoing an acid or base ionization reaction with water. Aqueous salt solutions, therefore, may be acidic, basic, or neutral, depending on the relative acid-base strengths of the salt’s constituent ions. For example, dissolving the ammonium chloride in water results in its dissociation, as described by the equation:
Salts are ionic compounds composed of cations and anions, either of which may be capable of undergoing an acid or base ionization reaction with water. Aqueous salt solutions, therefore, may be acidic, basic, or neutral, depending on the relative acid-base strengths of the salt’s constituent ions. For example, dissolving the ammonium chloride in water results in its dissociation, as described by the equation:
04:08Determining the pH of Salt Solutions
The pH of a salt solution is determined by its component anions and cations. Salts that contain pH-neutral anions and the hydronium ion-producing cations form a solution with a pH less than 7. For example, in ammonium nitrate (NH4NO3) solution, NO3− ions do not react with water whereas NH4+ ions produce the hydronium ions resulting in the acidic solution. In contrast, salts that contain pH-neutral cations and the hydroxide ion-producing anions form a solution with a pH greater than 7. For...
02:16Brønsted-Lowry Acids and Bases
In 1923, the Brønsted–Lowry definition of acids and bases was proposed by Johannes Brønsted and Thomas Lowry. According to this theory, a Brønsted acid is defined as a species that donates a proton in a chemical reaction and gets converted to its conjugate base. A Brønsted base is defined as a species that accepts a proton in a chemical reaction and gets converted into its conjugate acid. These transfers of protons are caused by the displacement of electrons in these reactions, which is...
01:21Basicity of Aliphatic Amines
Amines can behave as Brønsted–Lowry bases by accepting a proton from the acid to form corresponding conjugate acids. Due to a lone pair of nonbonding electrons, aliphatic amines can also act as Lewis bases by forming a covalent bond with an electrophile.
To measure the basicity of amines, two conventions are generally used. The first defines Kb as the basicity constant for the deprotonation reaction of water by the amine, as presented in Figure 1. Conventionally, lower Kb indicates higher...
To measure the basicity of amines, two conventions are generally used. The first defines Kb as the basicity constant for the deprotonation reaction of water by the amine, as presented in Figure 1. Conventionally, lower Kb indicates higher...
01:20Titration of a Weak Base with a Strong Acid
The titration curve of a weak base like ammonia with a strong acid like hydrochloric acid is the mirror image of the titration curve of a weak acid with a strong base.
Using the ICE table and substituting the Kb value, we calculate the initial pH of 50 mL of 0.1 M ammonia to be 11.11. Addition of 25 mL of 0.1 M hydrochloric acid to this solution of ammonia results in a buffer with an equal concentration of ammonia and ammonium ions. The pH of this buffer can be calculated by substituting these...
Using the ICE table and substituting the Kb value, we calculate the initial pH of 50 mL of 0.1 M ammonia to be 11.11. Addition of 25 mL of 0.1 M hydrochloric acid to this solution of ammonia results in a buffer with an equal concentration of ammonia and ammonium ions. The pH of this buffer can be calculated by substituting these...
01:08Titration of a Weak Acid with a Weak Base
Weak acids and bases do not undergo dissociation completely, and titrations between these two are rarely studied. When such studies are performed, say, for the titration of a weak acid with a weak base, the titration curve plots the change in pH as a function of the volume of base added. Take the titration of acetic acid with ammonia, for instance. During the titration, these two species form ammonium acetate and water, but the pH change is slow and gradual.
As a result, there is no simple...
As a result, there is no simple...