使-π

Josef M Maier1, Ping Li1, Jungwun Hwang1

  • 1Department of Chemistry and Biochemistry, University of South Carolina, Columbia, South Carolina 29208, United States.

概括

研究人员使用分子扭力平衡量度了溶液中银-pi相互作用的稳定强度. 这些在协调化学中至关重要的相互作用在-1.34到-2.63 kcal/mol之间,并且被证明对环境因素敏感.

相关概念视频

Precipitation Titration Curve: Analysis01:21

Precipitation Titration Curve: Analysis

The precipitation titration curve demonstrates the change in concentration of one reactant with the volume of titrant added. During the titration of chloride ions with silver nitrate, the precipitation titration curve is divided into three regions: before, at, and after the equivalence point. Before the equivalence point, low redissolution of the sparingly soluble silver chloride precipitate gives a low silver ion concentration. However, in the second region, representing the equivalence point,...
2.2K
Precipitation Titration: Overview01:26

Precipitation Titration: Overview

Precipitation titration involves the reaction of a titrant and an analyte to generate an insoluble precipitate. While precipitation titration uses various precipitating agents, silver nitrate is the most common precipitating reagent; titrations involving Ag+ are called argentometric titrations. Usually, the endpoint in a precipitation titration can be detected by visual indicators.
A precipitation titration curve demonstrates the change in concentration of the titrant or analyte upon adding the...
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Precipitation Titration: Endpoint Detection Methods01:19

Precipitation Titration: Endpoint Detection Methods

In argentometric precipitation titrations, endpoints can be detected visually by the Mohr, Volhard, and Fajans methods. In the Mohr method, adding a soluble chromate indicator gives an initial yellow color to the analyte solution. As the titrant is added, the first excess of silver ions forms a red silver chromate precipitate, marking the endpoint. The solution pH should be maintained at about 8 by adding solid CaCO3.
In the Volhard method, a standard excess of AgNO3 is first added to the...
6.6K