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Updated: Jun 9, 2026

Determination of the Gas-phase Acidities of Oligopeptides
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二甲基-胺基酸盐:基或胺基基? 一个实验和理论案例研究

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
PubMed
概括

一种新的酸试剂TMEDA.Na (mu-tBu) (mu-TMP) Zn (tBu) 被合成并进行了表征. 这种金属酸盐在金属交换反应中充当基,因热力学因素而表现出独特的反应性.

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Ions as Acids and Bases02:54

Ions as Acids and Bases

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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:
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Determining 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...
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Brønsted-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...
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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.
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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...
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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.
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